Simple Test for AL Casting Impurities

[ismengr]

Does anyone know of a simple (maybe by hand) hardness test or otherwise to test Aluminum for impurities based on hardness of the material at teh surface.

Current problem: Machining a casting (using carbide bits) from aluminum but there appears to be "dross" (technical term for impurities?) in the material, and as soon as the bit hits the "impure material", it stops drilling becasue the material appears to be too hard.

We currently don't have a way to test teh small surface on a standard harndess tester.

May your -dv/dt always be small.

 

[MintJulep]

Stop paying the foundry for the crap they are selling you and back-charge them for lost time and broken tooling.

The quality of your castings should improve markedly. If they don't, get a new supplier.