アルミニウム-珪素系鋳物合金の切削における工具付着物に関する検討

Abstract

During the cutting operation, the authors observed the deposits of the tool face and flank by an X-ray microanalyzer and the like on the aluminium-silicon casting alloys which showed comparatively severe tool wear, generated much tool deposit and were difficult to obtain good finished surfaces among aluminium alloys, and then searched for the relationship of tool wear to deposit formation. Cutting specimens are F-material which are cast metallic mold and T6 treatment material after casting of AC4B (Copper silumin) and AC8A (Lo-ex), and the tests consist of dry cutting with fhe sintered carbide (P20) and high speed steel (SKH4) tools. The results obtained are as follows.Flank deposits are divided into the stratum type and the ribbon type which is followed by rapid growth. The stratum type deposit is formed with flank wear as its basis and adhere rigidly to the tool flank 2 to 4 times greater than the flank wear width. The ribbon type deposit grows rapidly as the cutting time elapses at a speed faster than the cutting speed at which the built-up edge disappears, and the faster the cutting speed the more remarkable the growth of the ribbon type deposit. In this deposit T6-material generates earlier than F-material, but it is easier to generate F-material in terms of flank wear width. The flank deposits are divided into the stratum type part containing a large a mount of Al, the part with piled-up Si, Mg, Ni, etc. and the part to which Al seems to have readhered. On the other hand, the tool face deposit protects rake face as a comparatively thick stratum for a low cutting speed, but for a high cutting speed, adhesion wear advances and at that time Si particles may play an important role in the advance of wear.