On the Flank Wear of Carbide Tool in Al-Si Cast Alloy Machining

Abstract

On the JIS aluminium cast alloy 8th class, one of Al-Si alloys, the flank wear of carbide tool is examined and the thin ribbon type deposit on the flank is sought by EPMA with respect to the origin and the mechanism of its growth. The results obtained are as follows.
As the ribbon type deposit is formed with the flank wear, its formation occurs when the flank wear width reaches about 0.2∼0.3 mm and the cutting temperature arises to about 500°C regardless of the tool material or the cutting speed. The flank wear advances by scratching of Si particls, and Co is removed from the tool surface to the flank deposit with rising cutting temperature under high speed cutting. The tool surfaces are partially destroyed as a result of losing the binder, which accelerate the wear. Ni which is contained in the workpiece is a homologous element and has strong affinity with Co, so that Ni seems to contributes to the removal of Co, and the carbide tool is abrased severely during high speed cutting of the workpiece containing a large amount of Ni. Si particles in the workpiece breaks into fine grains under a high stress condition near the cutting edge, subdivides still more, abrases pulling into and pressing against the tool flank, and hangs down as the ribbon type deposit.