High pressure die casting (HPDC) forces molten aluminium into a hardened steel die at high speed and pressure, then holds it under pressure while it solidifies. Cold chamber machines are used for aluminium. The process gives near-net-shape parts with thin walls, good surface finish and tight tolerances at high output, which makes it the main route for automotive and appliance castings in India.
Why it matters when buying
- Die casters mostly use secondary alloy ingots such as ADC12, A380 and LM24, chosen for fluidity and resistance to die soldering.
- Ingot chemistry consistency, especially Fe, Cu and Zn, directly affects rejection rates, so buy with a spectro report for every heat.
- Melt cleanliness and hydrogen control decide porosity; ask suppliers about degassing and fluxing.
- Runners, overflows and rejects generate in-house scrap that is usually remelted; outside sales of such scrap fall under Tense-type grades.
Notes
Standard HPDC parts contain some porosity and are not normally solution heat treated. For heat-treated structural parts, foundries use gravity or low-pressure casting, or special vacuum die casting. See choosing an alloy for die casting.