7 WAYS TO IMPROVE YOUR DIE CAST COMPONENTS

Transcription

1 7 WAYS TO IMPROVE YOUR DIE CAST COMPONENTS

2 Design for manufacturing (DFM) is a core methodology that ensures your die cast parts perform to specification and require the minimum of secondary operations. This is important when you consider that these operations can often represent as much as 80% of the component cost. Discover our top tips for improving product efficiency, extending tool life, and lowering part costs. 2

3 01 REDUCE WEIGHT, SAVE MONEY Reducing weight saves on material costs, leading to production efficiency with shorter solidification times. To achieve this, avoid oaverly thick cross sections. See figure 1 for a simplified example: Fig.1 3

4 02 REDUCE WALL THICKNESS TO LOWER COSTS When the wall thickness of a part increases, so does the process cycle time and material consumption all of which leads to higher costs. Figure 2 illustrates how minimizing wall thickness reduces the material content of the part and its cost. Fig.2 4

5 03 CONSIDER DRAFT TO SIMPLIFY TOOL MANUFACTURING Draft reduces the unnecessary complexity of tool manufacturing, facilitates the ejection of the part from the tool, and reduces tool wear, prolonging the life of the die. You should have twice the draft angle for inside walls or surfaces as for outside. This is because the material solidifies and shrinks onto the features that form the inside surface and away from those that form the outside surfaces. Shorter features require more draft than longer features. Figures 3 and 4 illustrate the different draft angles required for different metals. 5

6 03 CONSIDER DRAFT TO SIMPLIFY TOOL MANUFACTURING ALUMINUM DRAFT ANGLE DRAFT ANGLE IN DEGREES Standard Inside Wall Standard Outside Wall Precision Outside Wall Standard Hole 0 1 (25.4) 2 (50.8) 3 (76.2) 4 (101.6) 5 (127.0) 6 (152.4) 7 (177.8) 8 (203.2) 9 (228.6) 10 (254.0) 11 (279.4) 12 (304.8) LENGTH FROM PARTING LINE IN INCHES (mm) Fig.3 6

7 03 CONSIDER DRAFT TO SIMPLIFY TOOL MANUFACTURING ZINC DRAFT ANGLE 1.8 DRAFT ANGLE IN DEGREES Standard Inside Wall Standard Outside Wall Precision Outside Wall Standard Hole (25.4) 2 (50.8) 3 (76.2) 4 (101.6) 5 (127.0) 6 (152.4) 7 (177.8) 8 (203.2) 9 (228.6) 10 (254.0) 11 (279.4) 12 (304.8) LENGTH FROM PARTING LINE IN INCHES (mm) Fig.4 7

8 04 FACTOR IN FILLET RADII TO AVOID STRESS CONCENTRATIONS While critically important, fillet radii are often overlooked by component designers. To avoid high stress concentrations in the component and die, use fillet radii of the appropriate size in all internal and external edges. (The exception to this rule is where the feature lands on the parting line of the tool.) Figures 5 and 6 illustrate there is an optimum fillet size where structural parts are concerned. Increasing the fillet radii size will generally decrease the stress concentration at the bottom of a rib. Eventually, the mass of material added by the fillet will induce shrinkage porosity in that area. Fig.5 8

9 04 FACTOR IN FILLET RADII TO AVOID STRESS CONCENTRATIONS Fig.6 9

10 05 IMPROVE PART STRENGTH WITH RIBS AND WEBS Ribs and webs are an efficient way to increase part strength and minimize the effects of dimensional variation caused by substantial shrinkage. Ribs can be added where part strength is a concern and can also aid in providing a path for metal flow during cavity fill. Figures 7 and 8 illustrate how webs and ribs can be added to improve the mechanical design and deliver a more robust component. Fig.7 Fig.8 10

11 06 FACTOR IN EJECTOR PINS Ejector pins are required in most cases to remove the part(s) from the die. This results in a residual ejector pin mark on the part. In addition to automatically pushing the part from the tool after solidification, ejector pins keep the part from bending. Figure 9 illustrates how there are several ways to incorporate ejector pins. Ejector pin marks on most parts may be raised or depressed by 0.3mm. Larger parts may require additional pin tolerances for proper ejection. Ejector pin pads Fig.9 11

12 07 AVOID THREAD MISALIGNMENT External threads can be cast. However, a full 360 thread is not recommended. There is a risk of a slight shift in the halves of the tool which will cause the threads to be misaligned. Adding flats to the threads across the parting line of the tool alleviates this issue. Figure 10 illustrates how the recessed flat reduces the opportunity for parting line vestige to interfere with the component s function. Parting line flats added Fig.10 12

13 HELPING YOU DEVELOP BETTER DESIGNS There are many ways design for manufacturing can help you produce higher performing parts, in less time, for less cost. Dynacast runs regular DFM seminars to help today s design engineers understand the wide range of options open to them. You can learn more at design-seminars. Of course, we are also happy to advise on any specific issue or project. Simply contact us at DYN ACAST 7 WAYS TO IM P R OV E YO U R D IE CAS T COMPON ENTS 13

14 ABOUT DYNACAST Dynacast works with organizations all over the world, helping bring their ideas to life with the highest quality die cast components on the planet. Customers can come from virtually any industry consumer electronics, automotive, healthcare, or any other where only the very best is good enough. And each benefits from our 80+ years of experience pioneering the techniques and technologies that have redefined the industry. It means that every customer receives insight and expertise that adds value at every stage of the design and die cast manufacturing process. It s why today, across multiple industries and multiple geographies, Dynacast is the name synonymous with precision engineered metal components. Please visit dynacast.com to learn more. 14