What is adc12 / adc10?
ADC12 and ADC10 are Japanese-standard aluminium die-casting alloys used widely in Indian automotive components — gearbox housings, covers, brackets and pump bodies. Both are aluminium-silicon alloys with copper, and both are alkali-sensitive, so they must be cleaned with neutral-pH chemistry.
ADC12 carries roughly 9.6–12% silicon and 1.5–3.5% copper; ADC10 is similar with slightly less silicon. The copper content improves strength and castability but reduces corrosion resistance, which is directly relevant to how these parts behave after washing.
Alkaline cleaners etch these alloys. The visible result is a dull grey or blotchy surface, and beneath it a freshly exposed, highly reactive face. Add residual rinse water in a blind hole and a sealed package, and white rust follows within days.
The correct process is a neutral-pH cleaner at 55–65 °C, a clean rinse, and a genuinely dry part before packing. On die-cast housings, Power Clean has recorded white-rust rejection falling from 3.2% to 0.4% on exactly that change.
