- Thermal cycling simulation of the die
- Blowing and spraying thermal effect of the release agents
- Optimization of thermoregulation
- User friendly: full die simulation can be easily set up in few minutes even for the most intricate of dies
In high pressure die casting the average working temperature of a die is commonly related to the end of the cycle, with values in the range of 390-570 C (for cold chamber) and usually allows a good cavity filling and a quick and uniform cooling of the die.
But the actual die heat balance is not easy to predict and some die maker and foundry’s choices (i.e. about the cooling channels design or about lubrication) are led by the experience in the search of a good compromise between a too hot and too cold die.
Too hot areas in the die lead to soldering, the surface layer of the lubricant-separator tends to a quick lowering and the die tear and wear increases; the cycle time increases, and the size instability of the component may show considerable shrinkage porosities.
Too cold areas in the die lead to difficult ejection of the casting, that shrinks around core pins and lug bolts. Also uncomplete filling and cold slugs are possible and gas porosities increase since the metal becomes solid faster during the filling time and the solid “crust” prevent the pressure to compress enough the residual air.
The factors contributing to the die heat balance are well known, starting from the principal heat source (the cooling metal) to the main media for heat loss (die thermoregulation and lubricant application).
But it is not so easy to assign them a general contribution percentage to the heat balance and it may be difficult to understand what to change when die temperature related issues occur.
During production thermo-cameras and sensors are very practical and helpful tools to detect the actual situation but it is extremely important to predict possible issues when the change costs are least, that is during the die design and machine setup phase.
The thermal module within Castle – Therm – is a step forward in the die heat balance calculation in high pressure die casting. The multiphase analysis (metal, air, coolant) provides an accuracy level not previously reached. The cooling media flow inside the cooling channels is actually simulated as a fluid domain. Thermal exchange between inserts (i.e steel) and media (i.e water or oil) is not an input (as in the majority of the simulation software on the marketplace) but it realistically and automatically calculated as a function of the coolant flow depending on position and time.