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An Introduction to Precision Die Casting: Frequently Asked Questions
The die casting process can have significant advantages over other manufacturing processes—like machining and stamping—leading to major cost savings in piece price and overall cost of production. With die casting, you can create complex net-shapes, including complex internal and external features with minimal Draught angles—minimizing secondary operations. But as with any production process, there is a lot to learn before making a decision on which process would be best for you component.
In January of 2021, Form Technologies hosted the first installment of Metal Solutions Webinar Series – EU. This webinar, An Introduction to Precision Die Casting, presented by the European Dynacast team, aims to guide our customers on how to take advantage of the benefits of die casting. Our webinars present attendees with the opportunity to ask our experts real questions about the die casting process during our live question and answer section. Take a look at some of the most frequently asked questions below.
What is the minimum wall thickness for die cast components?
The minimum wall thickness that we can achieve is dependent on the part geometry and part design, but in an ideal scenario, Dynacast can cast Aluminium walls as thin as 0.3mm. Generally, a minimum wall thickness of 0.5mm – 1.0mm is advisable to maintain high strength.
What is the ideal wall thickness for die casting?
There is no one ideal wall thickness for a die casting component. Rather, it is exceedingly important to maintain consistent wall thickness and reduce weight where possible for a strong, cost-effective component. The best way to achieve this is to design optimized gate and overflow locations into your part design to avoid unnecessary porosity and maintain strength.
What is the tightest tolerance Dynacast can hold?
Dynacast prides itself on maintaining the tightest tolerances in the industry, but similarly to wall thickness, the tolerance is largely dependent on part geometry. For the most exact tolerances, generally between ±0.001” and ±0.002” is possible for zinc, whereas Aluminium can hold between ±0.002” and ±0.004”.
However, even though a tolerance of ±0.001” is possible with Dynacast, manufacturers must be careful to avoid engineering unnecessary cost into the design. Too often, companies will request exacting tolerances and minimal Draught angles when such features are not needed to maximize part performance. As a result, their castings fail.
Instead, take a more holistic approach to your design. With the help of our engineers, determine the non-critical dimensions of your component to allow for more lenient tolerance zones. In addition to extending the life of your tool since there are fewer exact geometries that wear down, allowing for tolerance zones also makes it easier to plan the tolerance stack-up of your entire component. This will help you to avoid machining and secondary operations wherever possible, making your design work for you to get the most out of the die casting process.
Which die cast metals are environmentally friendly to use and produce?
All of the die cast materials that we use, Aluminium, zinc, and magnesium are environmentally friendly because they are recycled. At Dynacast, our plants work in a closed loop cycle, utilizing advanced re-melting capabilities to re-use any excess metal retrieved from our runner systems in the dies. After reclaiming the excess metal, Dynacast verifies the chemical composition with spectroMetres to ensure that they maintain the physical and mechanical properties of newly sourced metal.
In terms of production, Aluminium is the most environmentally friendly of all the die casting metals. Aluminium is 100% recyclable, and 75% of all the Aluminium ever produced is still in use today. Since Aluminium can be recycled again and again with no deterioration in its mechanical or physical properties, it can serve the same applications with the same level of performance as primary Aluminium extracted directly from bauxite ore—all while having a positive impact on the environment and your bottom line.
The physical and mechanical properties of Aluminium make it the ideal choice for parts that can be used in almost any industry, including aerospace, Defence, consumer electronics, healthcare, automotive, and more. Learn more about out recycled Aluminium capabilities with our blog.
What are the benefits of die casting over screw machining?
The benefits of die casting are largely associated with production speed and total piece price savings. Dynacast’s multi-slide machines can be designed with multiple cavities and enable our engineers to cast extremely complex parts, quickly. Our multi-slide die casting machines cycle at speeds of up to 75 cycles per minute, delivering 4,500 shots per hour. In a two-cavity tool, this means 9,000 parts per hour.
A faster cycle time contributes to lowered overall cost per piece. Additionally, die cast tools ensure unmatched complexity of internal and external geometries, so there are fewer secondary operations associated with die casting. With multi-slide die casting, you can cast complex geometries that would otherwise need to be manufactured from two or more pieces and assembled using any other processes.
While screw machining offers a lower up-front tooling cost, die casting more than makes up for that in the overall peice price savings. On an ideal part (one that is small, high volume, and can be cast in zinc), the tool is paid back in full somewhere between 10-14 months of production. Every part made after that is an earning towards your bottom line.
Do you have materials that are corrosion resistant without surface treatment?
The level of environmental resistance offered depends on the material and your project requirements. Zinc, for example, is relatively self-resistant in comparison to Aluminium alloys, but you will get some zinc oxide, or white rust. However, if you need a high level of environmental resistance for your die cast component, we recommend utilizing one of our surface treatments—from treatments and coatings that offer corrosion resistance, high-gloss finishing, painting, and more.
How can you determine if die casting is cost effective compared to other fabrication processes?
The cost effectiveness of the die casting process needs to be evaluated on a case-by-case basis. There are many cases in which converting to die casting from screw machining, machining from solid, stamping, and welding results in better part performance and better cost at full-scale production. However, we invite you to contact an engineer to determine if converting to die casting is the best solution for you.
With over 80 years of experience, Dynacast consistently delivers value through engineering expertise, efficient operations, and Advanced Quality Planning systems. If you’re interested in learning more about the die casting process or Dynacast’s unique capabilities, sign up for our free on-demand seminar and view at your convenience.