Die Casting Tools: Quality, Maintenance, Replacement
Tool Quality, Tool Maintenance, and Tool Replacement
When it comes to being a successful manufacturer, you want to get the most value out of each step of your production process, and it can be tempting to cut corners. Without knowing much about the importance of tooling, some manufacturers can slip into the trap of cutting cost with cheaper molds.
Great tool design is critical to the overall success of your project. No matter how advanced your die cast machines are, if you cut costs for a cheaper tool, you run the risk of creating mediocre parts, adding costs with unnecessary secondary operations—or worse, complete project failure.
Sign up for our free on-demand webinar and learn about the importance of quality tooling to see the most ROI on your project, how to properly maintain a tool, and when it’s necessary to replace your die cast mold. In this webinar, we’ll cover
- What makes a quality tool
- Dynacast tool maintenance standards
- Designing to prolong the life of your tool
- And more!
Fill out the form below to sign up for our free on-demand webinar:
Transcript: Tools for Die Casting: Quality, Maintenance, Replacement
Carly East, Content Strategist:
Hello, everyone, and welcome to today’s Metal Solutions webinar, Tools for Die-Casting: Quality, Maintenance, Replacement presented by Form Technologies. I’m Carly East, content strategist at Form Technologies and your hostess for today’s webinar. Before we get started, I’d like to go over a few housekeeping items, so you know how to participate in today’s events.
There is no dial in for this webcast. All audio will come through your computer’s speakers. All widgets are moveable and resizable, so feel free to organize your console in a way that works best for you. You can utilize the resources widget to view additional resources. There, you can access a free download of our whitepaper Engineering Value: Balancing Design with Cost Effective Production as well as one of our most recent blogposts on optimizing your diecast tool.
There are also several other resources like this available in the knowledge center of the Dynacast website. You can submit questions via the Q&A widget. I see a couple people have already submitted questions prior to the start of the webinar so feel free to take advantage of this feature during the webinar as well. We will be holding a live Q&A session at the end of the webinar and try to answer questions in order as they come in so make sure to get them in early. If we’re unable to get to your question we will have an engineer follow-up with you via email after the webinar.
If you have any technical issues like no sound, slides aren’t moving, or anything else, please submit a comment via the Q&A widget and we’ll do our best to troubleshoot. As usual, this webcast is being recorded so if you’d like to rewatch the presentation or if you miss something you can use the same link that you used to access this live webinar again in a few short hours.
This webinar is presented by Form Technologies, a leading global group of precision component manufacturers including three major brands. Dynacast for diecasting. Signicast for investment casting, and Optimim for metal injection molding. With our world class technology and processes, we can serve any industry at virtually any volume with superior components and outstanding part to part consistency.
The Form Technologies group of companies operates 29 design and production facilities in 19 countries worldwide. Together, our entire business is focused on delivering the highest level of quality at scale. Dynacast is the world’s leading global manufacturer of complex precision components, helping customers solve their manufacturing challenges with state-of-the-art technology, automation, and advanced tooling techniques. Today, we have two experts with over 30 years of experience with Dynacast to help present.
First, we have Bill Dodge. Bill’s been with Dynacast for over 26 years and is currently the engineering manager for Dynacast’s tooling division. Prior to this role, Bill worked as an engineering manager at another Dynacast facility and as a tool design engineer for 10 years. Bill specializes in tool design, tool optimization and design for manufacturability practices. This is Bill’s second time hosting one of our webinars and we’re grateful for his time and expertise.
Next, I’d like to introduce you to Nate Moore. Nate has been with Dynacast for five-and-a-half years as a design engineer and brings several years in manufacturing experience to the table. Before joining Dynacast, Nate worked for a spin caster specializing in design optimization and quality control. At Dynacast Tooling Division, Nate specializes in additive manufacturing. Nate is a pro at increasing production efficiency and implementing new technologies. Each of our presenters has exceptional experience with optimizing tool design for a better part performance, longer tool life and more ROI.
They’ve worked really hard on this presentation for you all and as you’ll hear, they’re excited to jump into conversation about what goes into manufacturing quality tools for die-casting. Bill and Nate, thank you kindly for presenting with us today. You can go ahead and get started.
Bill Dodge, Engineering Manager of Dynacast Germantown:
Thanks, Carly. I’m Bill Dodge. As Carly mentioned, engineering manager here at Dynacast Tooling Division.
Nathan Moore, Design Engineer of Dynacast :
I’m Nate. I’m the design engineer and I’m excited to share with you guys how we make some great tools. We’ll let Bill start it off.
Bill Dodge:
Here’s kind of the bullet points of what we’re going to go over today. We’ll give a brief overview of our tooling division here. We’ll get into some of the features and requests that we’ll probably make on your parts for DFM or design for manufacturing. We’ll show some flow simulation examples and briefly discuss some components and materials and then we’ll also share some tooling examples. Then we can get into some Q&A at the end.
So, to start off, we’re going to show a quick video that shows some of Dynacast capabilities. You get a glimpse of some of our production operations and toolmaking. Actually, you’ll see some of the tools during the build phase.
Video:
What does it take to create world leading precision metal components? It starts with people. Experts with decades of experience. Experts who truly understand what it takes to design for the real world of manufacturing, experts, who transform designs to make resulting die what we call a tool stronger, more accurate, and longer lasting. Then it’s about marrying that insight with the most advanced tooling technology in the industry. Technology that creates tools with super tight tolerances, tools that are easier to maintain with less downtime that reduce parts requiring little or no secondary work. We should know. Dynacast designs the tools to create high precision components for some of the most demanding companies on the planet. We do this across more than 20 locations worldwide and we do it at scale. Discover how our approach can help you create stronger, lighter, better performing components. Visit Dynacast.com to learn more.
Bill Dodge:
Okay. As we mentioned before, we’re representing Dynacast Tooling Division here, or DTD. We’re a full-service tooling center. We have 24 thousand square feet. We’re located in Germantown, Wisconsin. We have approximately 30 employees at the facility. We have toolmakers, machinists, design engineers. We have over 40 years of experience here, and we work directly with the production plants during the design phase of the tool. So, we’re not operating solely on an island her. So, this allows us to combine input from out toolmakers as well as the plant’s production departments, their quality departments so that we’re not just designing for the quality of the tool build but we’re also designing for the performance of the tool and the long-term maintenance of the tool.
So, we design and build tools from our small, multi-slide A2 tools all the way up to over 500-ton conventional aluminum tools. That picture on the upper left corner kind of shows the size range. We’ve got a small A2 tool sitting on top of a larger conventional aluminum tool. So, we mostly build tools for our North American facility, but we also build tools for Dynacast worldwide on occasion. So, we can build tools for a very short lead time depending on the project. Design and build A2 tools in under four weeks and large, complicated conventional aluminum tools in six to eight weeks.
We have all the necessary equipment in-house to complete builds. We also support the plants in refurbishment and repairs when needed, and we can sample and qualify our A2 tools in-house since we have a machine here on site. This is the only tool we could qualify on site. We don’t have any other production machines here.
Nathan Moore:
Here’s an example video of five axis machining. What you’re seeing is an insert being hard cut, hard tool seal. Later on, in the webinar, we’re going to talk about how we can adjust your part to facilitate added machining like this which can almost speed up tool build time.
Bill Dodge:
So the point of DFM or design for manufacturing is to design the casting or your part in such a way that we can optimize the efficiency, the performance, the build, the longevity of the tool. We recommend if you can involve us early and the design stage this way there’s probably a better chance that we can incorporate these design changes early in your design process rather than later on when your design probably becomes a bit more rigid.
We are seeing some more projects kicked off solely with 3D models. However, it’s very beneficial for us to have these 2D detailed drawings. It’s crucial to have front engineering of the tools because your tolerances, your cosmetic features, your data structures and allowable draft and radii greatly influence how we’re going to design and build our tools. If you solely give us a 3D model, so maybe you have a part that’s modeled. You’ve got a one inch external feature modeled up but we don’t have the prints. You may want that tolerance plus nothing, minus let’s say ten thousandths.
Without the print we wouldn’t be able to adjust for that. We want to target nominal to give us a little bit of room in the tool. We don’t want to be up on one end of the tolerance. So, if your model was all the way up at the high end, we’d prefer to be a bit closer to nominal. So, we’ve got some leeway for the tool making process and also for the ware of the tool. So, if we were at the one end of the tolerance we’d have to replace or rework that tool sooner just to stay in tolerance.
Also, whenever possible if we could have information on mating components, assemblies. I know that’s not always possible. There’s some proprietary information but when it is it’s very useful for us and we can understand which areas are more critical than others, which areas of the department might be more flexible that we can change to benefit the tool build and tool design. So, the more information we have on a part the better.
Nathan Moore:
Let’s talk a little bit about draft now. Draft is necessary on surfaces parallel to the direction of ______ in the die and helps facilitate part ejection from the tool. Insufficient draft could result in bent castings, possibly could get stuck in the tool or ______ 00:11:49 all the casting of the die field. These issues end up resulting in premature wear, die damage, and then in turn tool downtime.
You can technically draft every feature optimally based on how deep it goes in the mold but this is not common practice. We normally draft features generally per side, whether it’s an internal or external of the cavity. For internal walls, we usually draft twice as much as the external walls. This is because the alloy solidifies on to features on the inside surface and away from features on the outside surface. If you look at that picture on the right-hand side, you have that light blue internal surface, so the casting is going to solidify and shrink on to that making it hard to pull off and then it would be the outside of the cavity that’s going to pull away. So, you don’t require as much draft on the outside, dark blue, as we do on the inside with the light blue.
Different casting materials, whether it’s zinc or aluminum and the process we do will determine the amount of draft. That’s what that little chart on the bottom left hand over there is talking about. So, usually for precision aluminum we require more drafting with zinc.
Now we’re going to talk about ______ 00:13:11 in radii. These are important because they help strengthen the casting and aid in material flow through the die. They also help reduce stress concentrations in the tool. They also aid in the build of the tool by reducing potential processes, increased radii and we simplify the electrodes required for the EDM process or enable us to hard cut the die field and eliminating the EDM process altogether. That’s what we saw on that five axis machining video earlier. We were just ______ 00:13:39 so that part may not have been needed within EDM.
Typically in model construction, during model construction it’s normal to add draft first. Then we radii and fill it. If you’re uncertain how to draft your part though you can always send us a file without any draft or radii. This makes it easier for us to manipulate your model to add draft and radii, although some of the more advanced CAD tools we have are allowing us to modify your customer parts easier even if they do have lots of drafts and several radii.
Typically, when adding radii we want to maintain a constant wall thickness wherever possible. Above are some examples of common situations when designing a part. We’re not going to dive too deep into this slide but just know you can utilize our Dynacast knowledge center on our website or the widget on your screen. Then recommendations for rounds, graphs, ribs, and several other design considerations can all be found on the site.
Bill Dodge:
So, another feature we’re going to request when we’re designing a part for manufacturing will be injector pins. The injector pins are required to extract the casting from the die. There are some exceptions and our small multi-slide process we can strip parts off internal cores or inserts. With injector pins, we want to have a nice balance of injector pin layouts to ensure the casting ejects straight and repeatedly. We look to place these pins near areas that have higher shrinkage forces such as cord holes. Insufficient ejection could result in bent or stuck casting, which also leads to die damage and tool downtime.
Now, these injector pins do leave a weakness mark on the casting. The pin holes in the die still do eventually wear so these weaknesses can grow or flash over time. So, for this reason, we’ll typically rest the pins in pads in order to avoid interference with mating components. You can kind of see in that upper right image where the injector pins are and they’re recessed in little ______ 00:15:53 usually about .3 millimeters recess on some conventional aluminum parts.
If this raised material ______ 00:16:04 from the injector pins poses a problem with the function of your part or a concern, we may be able to add features to the part or redesign a draft in such a way to flip the ejection to the opposite side of the part, so a non-critical side of your part.
Nathan Moore:
Let’s talk about some tool simplification now. Designing for a constant wall thickness is typically advisable. We usually want to minimize heavy wall sections that retain higher temperatures that could lead to heat checking or cracking in the die steel. In some configurations though this adds unneeded complexity to the die cast tool. It’s important to think about how these features affect the tooling requirements when you’re designing. Maybe they can give you design to simplify the tool instead of just making a part look better or making it a constant wall thickness. If you look on the image on your screen, number one, this is a tool that has four pull directions. We have top, bottom, left and right.
On image two there, we have a redesigned part specifically for HPDC, high-pressure diecasting, where we can then reduce the four pulls to two pulls of direction, and we may increase some wall thickness in this part but it’s an added benefit to reduce that tool cost. When you have multiple slides, not only does it cost more in tooling but then we have extra-rare components that may need maintenance in the future.
Bill Dodge:
So, here’s another example of redesigning parts to eliminate a required side pull. You can see in that first image there’s a slide pull required for those ______ 00:17:52 that are blind, internal to the part. Image two, one option could be to move those ______ 00:18:01 to the outside of the casting to eliminate that slide. Another option might be is shown on three is to open up a window through the part so the die still can come through and form the underside of those features.
Or maybe it’s simple and just extending those ______ 00:18:16 down to the mating cast material. That image there on four does create a heavier wall thickness, so it would be optimal to remove the material from the opposite side of the part as shown in image five to maintain a constant wall thickness. So, when you’re designing your part maybe you can identify the required parting lines, so where the mold needs to be split from one half to the other.
See if you can identify some bad steel conditions ahead of time. So, this part you can see there’s a valley required for the parting line. The blue translucent surface kind of gives you an idea of what the parting line would look like. We’ve got a deep, thin piece of steel that could be prone to failure. So, we could look to insert this area and plan for replacement but it would be much better if we could redesign the part and eliminate that for a steel condition altogether. So, in this example we just simply filled in that area requires, that step in the parting line and this allows the parting line just to come straight across. There’s much more robust situations.
If we were concerned about constant wall thickness we could look to core out the backside if possible on the part to maintain that constant wall.
Nathan Moore:
Here’s another additional example of some poor steel conditions we often see. If you look on your tool images here, we have our two parts. They serve the same function and the black line on the screen you see is the cross-sectional area of what the die steel would look like. That profile on the left shows that we’d have some really sharp pieces of steel. We often refer to these as mice edges in the tool, and it would not last long in production.
On the right, we have altered the geometry of the casting to create a more robust tooling condition. These adjustments don’t change any function of the part. It’s purely more of a cosmetic. Here is the actual steel models up now instead of the cross section. We don’t have the most ideal steel condition on the opposite side of the part but it’s still a lot better than the knife edge we had before, and this is something that’s more manageable and something we could deal with.
Now we’re going to talk about some flow simulation. We use Magmasoft as our flow simulation software, as a lot of the rest of the Dynacast or Signicast. We use it as well. Magma is our flow and thermal simulation software. It’s a very powerful tool we use throughout the entire design process. It’s used to find potential issue areas in casting, to optimize gating and overflow placement, as well as optimizing cooling channels for consistent die temperatures. Sometimes, altering part geometry can aid in filling of the cavity, possibly reducing porosity and making melt flow more favorable.
Bill Dodge:
So here’s just one example where we might be altering the casting for the flow. So, when we’re designing our die we need to consider the ingate location. Depending on the alloy and the process that we’re running or the molten metals entering the die at approximately 15 hundred inches per second. So, we want to avoid gating directly until ______ 00:22:02 steel whenever possible otherwise we could quicky erode the die steel.
So, in this example you can kind of see there was a ______ 00:22:13 around this part and the ingate location would just blast straight into the die steel and erode that wall. We’re able to work with a customer to increase the thickness of the flange to move the gate location up, and you have more of a direct path across the parts and reduce any potential erosion.
Nathan Moore:
This is an animation made in Magma to demonstrate the issue shown by Bill in the previous slide. During the DFM process, we determined to move a flange by the gate slightly. In the video on the left, you can see the melt entering and hitting that wall almost immediately. The right video shows the melt now entering at a higher level, avoiding that same wall. By doing this small change to the casting we reduce the risk or erosion significantly, and this helps to ensure that we get the maximum amount of shots out of the tool.
This is an example of adjusting a ______ 00:23:45 with a ______ 00:23:46 to create a more uniform section with better filling. In the left video, you’ll see the full front passing underneath the ______ 00:23:54 and trapping more air near the ______ 00:23:59. The right ______ 00:23:58 has a ramp which works twofold. One, it helps create a more uniform cross section helping to reduce any shrinkage porosity. Second, the ramp helps direct melt up into the ______ 00:24:09 filling it faster. This moves the air from the ______ 00:24:10 back into the body where it can then be dealt with easier with either overflows ______ 00:24:14.
We also use Magma for runner and overflow design. We will be viewing the entrapped air mass result that Magma has. This result allows us to see which areas of the casting are at higher risk for porosity and then try to mitigate these issues. What you see here in the left video is a casting that we currently have no overflows on. We will simulate a basic runner and see how the flow behaves to determine what are some ways that we could improve the tool design. Near the end of that video or that animation you can see that the mouth seems to backfill a bit near the runner so we’re stuck with a high concentration of air in the casting.
On the right video, we increased the gate area and simulate filling on the longer edge of the casting. This larger gate allows us to fill the cavity faster and have a shorter filling time. The fast filling also allows for longer intensification before the gate freezes off and we are unable apply an pressure to the cavity. Even though both these results don’t look the best it is potential to get a good casting out of them. Since we’re able to squeeze the casting at the end of fill with intensification a lot of that porosity could be squished very tightly and you’d have a perfectly usable casting.
This next example or for this main example we chose to go with the shorter gate even though we have a longer fill time. That was not an issue for this. We then placed overflows near the last fill position of the casting and then added vents to those overflows. The vents are not shown but this allows air to be pushed out of the cavity, which in this case is near the end of fill.
Because of these well-placed overflows we get a very good end result of less than one microgram of trapped air mass. This is significantly less than the air mass you saw in the two previous videos. We didn’t have the… the scale actually maxes out at one microgram and the two images before actually were way above that. So this iterative process in addition to a ______ 00:26:37 is what allows us to achieve optimal casting quality.
Bill Dodge:
We were having a little issue with the transition there. So now we’re going to get into some materials and components. So materials and components play a large factor in the tooling. We’re using premium die seals in our tooling. There’s a bit of an added cost in this but it’s necessary to improve this life of the tool. We’ll utilize different steels depending on the cast alloy, what machine we’re using. The function of the component and the die and other reasons. This image here just is one example of cavity fill we use in a conventional aluminum tool versus typical H13. We can also utilize die coating if we anticipate issues with wear or ______ 00:28:16 or soldering.
This can add quite a bit of cost to tool though and also require a longer lead time for the build of the tool.
So, obviously we can’t oversimplify everything. There are certain geometry requirements your parts need so we have to kind of plan for potential failure points. So, we’ll look to design our tools with maintenance and repair in mind. We’ll insert areas that we anticipate to have a high potential for failure or high wear. Maybe areas with lower draft allowances or areas with non-ideal steel conditions or areas in line with the ingate that can’t be avoided.
Earlier, we discussed some injector pins. So, we’ll look to insert these areas if we need to keep the flash line to a minimum depending on your part requirements. These are some images of inserts. The one on the upper left is peppered with quite a number of inserts. You can see in the red these are areas that are a bit more delicate in the tool or we envision to have more wear. The image on the right side, there’s a red insert there right in line where the ingate would come in. The ingate isn’t shown from the other side. So, this is easily replaceable so that we don’t have to replace the whole die if we encounter a version as an ingate.
The image in the middle there shows a stack of smaller inserts. There’s this part requires a large number of thin blades of steel. So, these could be prone to failure, so we’ll insert these areas so that it’s easier to replace. This would also aid in the building of the tool since they are removeable. We can work and polish these inserts individually and get a nice surface finish to ensure a good part release from the die and more efficient running of the tool.
That image on the lower left is just kind of one example of what a smaller insert might look like.
Nathan Moore:
There’s another application for utilizing inserts and that would be for combo tools. If you have multiple castings that are very similar and have low production runs we can look to insert these unique areas in the tool. This way we can utilize one tool with interchangeable inserts rather than building multiple complete tools requiring less tooling investment. The image on the upper left is the full tool and it was on the upper right is that piano looking part. That’s all the inserts and those can actually be swapped in any order that you want. So there’s a switch panel. You can have the largest switches near the back, near the front. It allows for multiple different combinations all in one tool.
Bill Dodge:
So as we said earlier, we don’t want to add additional slides if they can be avoided but many times it’s just not possible. But it’s just one example of multi-slide tool. We have four direction of ______ 00:31:43 on our smaller multi-slide machines and two directions of pull naturally on our larger conventional machines. So, we need to achieve additional pulls we’ll have to add either mechanical or hydraulic slides.
In zinc diecasting tools, we can also pull geometry internal to the casting with lifters. So, this tooling example has seven unique pull directions. It’s got the main open, closed parting line, mechanical slides pulling the perimeter of the part and this particular part had a feature inside the casting as you can see in the middle lower view cross section to the casting that’s shown on the left. But there’s a back drafted feature that could not be redesigned to pull to the outside of the part and had to be pulled internally. We’re able to do that with a lifter to pull that undercurrent geometry in the die steel.
Nathan Moore:
Unfortunately, porosity-free castings are unavoidable in high-pressure diecasting. We can reduce the amount of porosity with good tool design but sometimes we may even need additional strategies for best results. We can add backing systems to achieve the lowest porosity possible in a casting. This is a bit more costly to implement in the tool, so we only utilize it when it’s absolutely necessary. The image on the left there is actually a backing valve that’s used in the vacuum process and the tool on the right is an example tool that used vacuum and that’s the part in the first video you guys watched that sort of slides across the screen. You saw that tool actually being made in that video.
Bill Dodge:
So we’ll share a couple of tool examples. We’ve been highlighting ways to design out unnecessary complexity, but I don’t want to give the impression that we can tool off more complicated tools but when it is necessary. For these more complicated tools it’s even more important that we implement as many of the DFM features as possible to make the tools more robust and run more efficiently and maximize our uptime. So, here’s one example. This tool was an ______ 00:34:01 award winner. It has some very complicated parting lines as well as geometry that needed to be pulled at an angle below the die steel main parting line.
Our Dynacast sales team worked with the customer to redesign an assembly of parts, machine aluminum extrudents to a single diecasting component for this application.
Nathan Moore:
Here are some examples of some three plate tools with multiple internal slides. Three plate designs are more complex and allow us to gate in unique areas and can also aid in the casting extraction from die. The tool on the left has six different pulls of direction with gating below the main parting line. The tool on the right is assisted by two hydraulic cylinders which allow us to have greater pull force as well as independent movement of the slide. In the case of the image on the right we needed the independent movement of the slides to achieve the complex part.
Here are some final examples of some more complex tools we’ve built. These tools have many different pulls of direction with complex internal features. We talked a lot about DSM and how it could be very beneficial. Even with good DSM parts can still be very, very complex. A high level of experience in addition to the closed loop feedback we have with those plans allows us to handle these complexities to make great tools for our customers. Thank you for attending the webinar. I think we’re going to give it back over to Carly to take over for the ending comments and Q&A.
Carly East:
Thanks, guys, for another really great informative webinar. Just a reminder to everyone in the audience, please go ahead and submit your questions via the Q&A widget and we’ll do our best to get to everyone. We’ve already got a couple great questions in the queue, so we’ll go ahead and get started with those. All right. First question, is there any good way to easily remove soldered aluminum in a short time without damaging the die? In parentheses, surfaces treatment layer.
Bill Dodge:
Well, we’ve got some issues with soldering. We’re typically going to polish the solder off trying obviously not to damage the die steel and reduce dimensions on the die steel, but if we do have problems with soldering we’ll look to coat the die or inserts to prevent the soldering altogether. So, we’ve got several different options for die steel coatings to combat the soldering.
Carly East:
All right. What is the average lifespan of a die cast mold?
Bill Dodge:
Well, that’s very complicated. It depends on the part geometry. It depends on the process. So, our four slide zinc tooling, those tools last, I would say the longest. Next would be our conventional zinc tools and last would be the conventional aluminum tools. It’s greatly dependent on the geometry of the part. If we’ve got open and closed parting lines, if we’ve got complicated step parting lines. If we’ve got slide pulls with more wear items. Maybe some parts have heavier wall thicknesses that could lead to heat checking. So, it’s very geometry and part dependent.
Carly East:
All right. I’ll go ahead and add to that and say that if you have any questions about a specific project let us know and we’ll put you in contact with a sales engineer because they’ll be in contact with plants and have probably a more specific answer as well. Another question just came in that I think is really great. So, I’m going to skip this one upfront. If the part gets stuck to the die what are possible reasons and possible solutions?
Bill Dodge:
Yeah. Parts could be stuck if there’s insufficient draft. I know lube plays a big factor. We utilize die lube in production to release the casting. Obviously, we’re looking to design in as much draft and radii ahead of time to avoid stuck castings but they do tend to happen. You could have some…if parts have maybe some heavier wall sections we’ve got some high heat areas. We do have a bit of solder build up and you could have a little bit more adhesion from the castings over time to the die steel which could lead to some stuck castings. So, there’s many reasons that it could potentially cause stuck castings.
Carly East:
Then how might you solve for that if it does happen?
Bill Dodge:
Well, we can look at…if it’s a die soldering issue maybe we haven’t coated the dies previously. We could look to add some coating. Maybe we have to add some additional injector pins if the part’s not ejecting quite squarely if it wasn’t anticipated ahead of time. We tend to maybe go in and polish a little bit more draft in those areas that are thick and heavy. So it really depends on the geometry and what’s causing it as to how we would tackle it.
Carly East:
Awesome. Are there any new achievements on reducing a draft angle for high pressure die casting?
Bill Dodge:
Well, the die coatings help in ______ 00:40:08 and release of the castings. We’d prefer the increased draft over the cost of the coating. If we have additional injector pins and injector locations we could get away with some less draft to make sure the parts come out straight. So, there’s kind of a tradeoff there with less draft, more injector pins, but I guess I want to look at the part to see what areas maybe you’re looking to have less draft on. We do require less draft on our smaller four slide tools versus the larger conventional tools. So, depending which alloy or how big the part is we can cast areas with less draft in different processes. So, I’d like to see the part and discuss it further.
Carly East:
So while you’re on the subject of the different tools, someone has asked, what’s the difference between a conventional tool and an A3 tool?
Bill Dodge:
Between convention and A3 did you say?
Carly East:
Yes.
Bill Dodge:
Our multi-slide tools we’ve got our A2 machines or A3 machines, they’re setup in more of a crosshead setup. They’ve got four directions of pull. These are the multi-slides. Conventional, we refer to those for a larger hot chamber or cold chamber machines or just have an open and close. Your typical die casting press similar to a plastic injection machine. It’s got just two main directionary pulls and they’re a lot larger machines than our multi-slide machines, a lot higher tonnages.
Carly East:
Okay. Great. Let’s see. We’ve got a lot of good questions in line. One of our attendees is asking why do you choose to use inserts within a tool if the tool can only ______ 00:42:27 between 80 thousand and 100 thousand shot?
Bill Dodge:
I didn’t quite hear.
Nathan Moore:
What as the question with including inserts?
Bill Dodge:
I guess the attendee is asking why would you choose to use inserts in a tool if the tool itself is lasting between 80 thousand and 100 thousand shots.
Nathan Moore:
Well, one example would be the erosion issue we had. The Magma and the moving of the flange to avoid the wall, that erosion can happen very, very quickly so even though the tool may be supposed to be lasting 80 thousand shots we want to be able to enter that area sooner so that we’re staying within tolerance of the potassium requirements. So, that would be an area that’s very prone to erosion that would need to be replaced sooner. Sometimes, if you have a tap hole those tap holes can be very small and those core pin can be small and they can potentially break off if ejection isn’t perfectly square as well. Then having those areas inserted allow for easy replacement.
Carly East:
Okay. Cool. So speaking of inserts, how do you estimate the lifetime of parts within the die like cores, inserts, chill blocks, and ______ 00:43:48?
Bill Dodge:
That’s very part specific, too, and alloy specific. Whether it’s zinc or aluminum, whether it’s running in our smaller four slide or larger conventional tools. Are there bad steel conditions, delicate steel conditions on the inserts or cores? Do we have heavy wall thicknesses that could lead to heat checking? It’s very part specific as well.
Carly East:
Okay. We have one user asking what’s your approach to minimizing your eliminating heat check on a casted surface?
Bill Dodge:
Well, we want to try to maintain constant wall thickness so we don’t have any real heavy…to try to avoid heavy wall thicknesses which could lead to higher temperatures localized in the die steel, that could lead to heat checking. We want to have a very balanced cooling channel layout. This is one area that we could utilize our Magma simulations to do a thermal analysis to make sure we’ve got a balanced cooling channel layout. There’s a couple areas there to focus on to try to minimize the heat checking.
Carly East:
Okay. Let’s see. So we have one user asking what’s the approach to reducing the parting line on a casted part? So, I assume they mean ______ 00:45:26.
Bill Dodge:
To reducing the number of parting lines?
Carly East:
Yes.
Bill Dodge:
The one example we had earlier showing that there was a step in the parting line that had that valley of steel or thin steel. That was one example of how to reduce the parting line. Once we redesigned that part we had a nice, flat parting line. The other examples we have to eliminate the slides, reduce the number of parting lines required by changing the features so that we went from a four slide to just an open and close. So, if you’ve got quite a bit of flexibility in your part design we can work with you. If we can take a look at the 3D model we can work with you to eliminate steps in the parting lines or additional pulls that require additional parting lines on our part.
Carly East:
Okay.
Bill Dodge:
Sometimes you may have a cosmetic area on a part that you’re concerned about a parting line on. Maybe we would normally have two pulls on a part or we’d have a seamline or a parting line through a surface that you would deems is cosmetic. In those instances, we would actually introduce a slide into a tool that might necessarily ______ 00:46:54 then we can avoid a parting line on certain areas that you would need to be free of any parting lines for cosmetic reasons. That’s kind of a backwards approach but there’s a time where we do add slides to avoid parting lines in certain areas.
Carly East:
Awesome. Is there any heat treatment or finishing recommendations for the tools that you guys have?
Bill Dodge:
Is there any heat treatment or?
Carly East:
Yeah. Or a finish that might facilitate easier ejection from the mold.
Bill Dodge:
Yeah. For ejection from the mold we mentioned that there’s different die coatings that we utilize depending on the process, the alloy, and the geometry that we’re looking to release from the tool. ______ 00:47:52 treating is specific to the alloys, the tool seals that we’re using for the different alloys. We utilize a number of different heat treaters here, but typically going ______ 00:48:03 with a manufacturing recommendations of the die steel themselves that you’re treating.
Carly East:
I just got another really great question in. The ______ 00:48:17 seem to take a lot of material at each shot. Is that material recycled to other castings or if so is there some sort of process requirement before it’s recycled and put into another component?
Bill Dodge:
Yeah. So, for the conventional… the material in the runners tends to be pretty clean so that could be remelted. The materials in the overflows, that’s going to be a bit more dirty because you’ve got the material that’s flowing the runner system, through the cavity, into the overflow that’s picking up the die a little bit and other impurities. So, we’re not going to reuse that. That gets shipped out to the alloy vendors for recycling to return us back with some virgin material. But the material in the runners is kind of ______ 00:49:08. It’s the cleanest that does get remelted in the furnace.
Carly East:
Okay. Great. Thank you. We have one attendee looking for alternative assembly processes to replace screws and gaskets to cover complex water cooling channels. Would IMA, so injected metal assembly, be applicable for this application? Is it possible to use aluminum alloys instead of ______ 00:49:40?
Bill Dodge:
We do use IMA to merge components of different materials together, eliminating screws or rivets or other assembly methods. They’re using ______ 00:49:56 solely for the merging of the parts not aluminum. Aluminum parts can be merged together but merged together with ______ 00:50:07 zinc alloys. As far as the process or the part you’re talking about, it’s probably be best to get our IMA experts involved in that part in our ______ 00:50:22 plant. So, I would suggest getting them involved. I don't know if Carly you can get them the contact ______ 00:50:31 to look at the part a little bit more in depth.
Carly East:
Yeah. Sure. I will definitely have someone contact them because that sounds like a very specific project. Okay. I know you went over quickly for tolerances depending on materials but can you say again what kind of tolerances can be expected from various types of geometries as well as materials?
Bill Dodge:
So we ______ 00:51:08 tighter tolerances on our smaller four-side ______ 00:51:10 tooling. Open our tolerances up a little bit more on our conventional zinc and then we need a little bit more for our conventional aluminum. We’ve got great resources on the website that point out the tolerances for the different alloys and processes.
Carly East:
Okay. Then in that same vein, is there a maximum and minimum thickness for aluminum parts versus magnesium parts? I know we have really great thin wall aluminum capability but is there a sort of range that you like to stick to?
Bill Dodge:
It seems like two millimeter walls are very typical on aluminum. We can go a little bit thinner than that. Maybe a little bit less down to maybe 60 ______ 00:52:12 I guess, I wouldn’t really want to go much thinner than that and that’s generally an area that is our last place to fill rather than in the middle of the part. So for aluminum I’d recommend about a two millimeter wall.
Carly East:
Okay. So I have a question that’s a little bit more general. How would you compare zinc versus aluminum die casting? The attendee is asking about tool component injection parts ______ 00:52:43 radii. This seems similar to when you were talking about conventional versus A2 and A3 tooling. Could you give a quick overview about the difference between zinc die casting and aluminum die casting the processes?
Bill Dodge:
No. Zinc die casting process is what we called a hot chamber process where the injection system is submerged into the molten zinc and the material is delivered to the die through this submerged gooseneck system with the nozzle that butts up against the tool. This process tends to be less air entrapment versus the aluminum process which is a cold chamber process. So, there’s actually a cylinder or a shot sleeve and the molten aluminum needs to be ladled into the shot sleeve and then pushed through into the die with a plunger. So, there’s a bit more air that’s sitting in that shot sleeve above the molten aluminum that needs to be pushed through the cavity. So, we do quite a bit of simulations on making sure we’re pushing that air through the cavity.
The cold chamber process is going to tend to have more porosity than a hot chamber zinc process.
Carly East:
All right. I’ll make sure I follow up with this user. We have a great short YouTube video that explains the difference between hot chamber and cold chamber die casting. On to the next question, I have one that’s asking how you guys accomplished tight dimensions for slider moving portions or a moving die component?
Bill Dodge:
For parts? ______ 00:54:48 tolerances for parts with sliders or you mean on the multi-slide?
Carly East:
I think they might be talking about sliding rooting portions of the mold. I may be reading that wrong, so I might follow up with them after the webinar instead.
Bill Dodge:
______ 00:55:21.
Carly East:
All right. Back to remelting and reusing hot ______ 00:55:26 material. What percentage of remelt do you suggest and reusing and will increasing this percentage impact the structure of the part? They also ask if there’s a difference between remelting material for aluminum and remelting material for zinc.
Bill Dodge:
So how much remelt material are they using?
Carly East:
Yeah. I think they’re asking how much is okay to use.
Nathan Moore:
I mentioned earlier we’re using the runner systems, the remelting. Quantity-wise it’d probably be more of a production plant question.
Carly East:
All right. Good to know. Then we have ______ 00:56:18 if anyone has any other questions feel free to shoot them to me and I’ll try and make sure we get to answer them, but we have a couple left. I have one user asking what is the recommended material for prototypes versus full production tools? So if you were prototyping using the die casting process would you still use the same material for the tool?
Bill Dodge:
Yeah. We could prototype and run the same alloy if we’re looking at…so let’s say a conventional aluminum part. We could look to build a ______ 00:56:57 tool. So, it’d be maybe a single cavity unit die tool versus when you get into a multi-cavity production tool. But we’d be casting the same alloy. So, the tool cost would be cheaper up front for the prototype. We’ve got unitype bases that would just swap out the cavity inserts. So, we’d just be building the set of cavity inserts for the prototype part. Again, running the same alloy, proving out the part before we get into more costly multi-cavity production tool.
But we do have other…it really depends on the size of the part and what you’re looking for. We do have other applications of processes to prototype parts maybe close to a ______ 00:57:43 zinc. We’ve got some spin casting options that may be the same but the process would be slightly different. We’ve got different options for prototyping so it depends on the size of the part, the alloy and what you’re looking for.
Carly East:
Then I have one more question. I’m going to end on a specific one for you guys. Do we have the capability to cast one-and-a-half millimeter thickness aluminum casting while accomplishing a 0.3 millimeter flatness requirement?
Bill Dodge:
I guess I want to take a look at the part and see how large of a part we’re talking about. Get into more of the details of the requirements. So, Carly, you can pass the contact information whether it’s the plant or here and we can look at it in a little bit more detail.
Carly East:
Sounds good. I think that’s about all the time that we’re going to have for today. For anyone who didn’t get their question answered we will make sure that we have an engineer follow-up with you via email at the conclusion of the webinar. One more quick reminder, this webinar is part of our ongoing series, Metal Solutions Webinar hosted by Form Technologies. These webinars cover hot topics in diecasting, investment casting, and metal injection molding industries, and we host them once a month. So, make sure you’re signed up to our email so you never miss an invitation. One more round of thanks for our presenters Bill and Nate for taking the time to lend their expertise to us today. We hope everyone has a wonderful, safe rest of your week. Thank you for joining.
