HPDC: How We Pushed The Limits of Cycle-time With Scientific Precision
The die caster was awarded a very thick heavy bulky transfer case for a high power automobile application (over 700 HP engine). The die runs very hot in spite of measures to maximize internal cooling using conventional design practice along with heavy external spray. And even with this arrangement, die solder was the source of daily down time and scrap rates was due solely to the tearing of the skin of the cast part from die solder.
The customer needed to improve plant capacity and reduce scrap so that they can remain competitive. The key avenue for meeting these targets are to reduce the cycle-time and eliminate die solder.
BHOLSER was retained to analyze their current process and then to assess the challenges that will arise if they reduce their cycle-time by 20%. We simulated their existing process and pinpointed the precise die features that will exceed the solder threshold temperature; this correlated exactly with the foundry. This step confirmed that our simulations can precisely predict solder locations. We then found innovative measures to get closer to the die cavity (copper sleeve). However, some regions needed conformal cooling in order to eliminate solder from every die feature. PALCAM® was sourced for the tool build because of their reputation delivering quality die inserts made from 3D printed H13. Their extensive experience in conformal cooling design was instrumental in finding practical and functional cooling for those difficult to reach areas.
After a couple of design and simulation iterations, we confirmed that the proposed cooling not solder, even if the customer run 20% faster.
The end result (actual internal email exchange at the die caster):
“ . . . After running over 500 parts, zero solder, zero scrap from solder, zero down time . . .”
The most difficult part of this project was to understand exactly how to program the simulation software so that it can predict die solder.
Lesson learned on this project is to be careful and know at what time during dwell reveals the onset of die solder. We now have this in our arsenal when we support our clients in the future.