Tool Edge Wear of P/M High Speed Steel

Advantages of P/M high speed steel tools compared with conventional high speed steel tools are due to the former's lack of segregation and coarse particles within thin the crystallized carbide structure. Carbidide particles of P/M tools have a uniform distribution range of about 1μm in diameter, higher toughness, and excellent grindability. After turning and milling operation, the edge of the tools are carefully observed by the scanning electron microscope (SEM) to determine how the uniform distribution of the small carbide particles can affect the sharpenability of the cutting edge. The results show the P/M high speed steel tool minimizes the fall-off of carbide particles on the cutting edge, reduces wear on the flank face, and maintains sharpness of the cutting edge. However, under certain cutting conditions, in which crater wear readily forms on the tool face, the conventional high speed steel tool is superior in terms of tool wear.