Crater Wear

Crater Wear

Crater Wear - Crater wear is characterized by the formation of a crater or depression at the tool chip interface. Crater wear is caused by the pressure of the chip as if slides up the face of the cutting tool. The crater or depression formed on the tool face conforms to the shape of the chip underside and is restricted to the chip tool contact area. In addition, the region adjacent to the cutting edge where sticking friction or built up edge occurs is subjected to relatively slight wear.

Under high temperatures (as high as l000°C) experienced at high cutting speeds, H.S.S., tools will wear very rapidly because of thermal softening of the tool material. With carbide tool materials, although they retain their hardness at these high temperatures, solid state diffusion can cause rapid wear.

Under very high speed cutting conditions, crater wear is often the factor which determines the life of the cutting tool: the cratering becomes so severe that the tool edge is weakened and eventually fails.

Crater wear takes place at feeds greater than 0.1.5 mm/revolution at low or moderate cutting speeds. Lack of lubrication during cutting enhances crater wear. Slight cratering may improve cutting action, but increased cratering weakens the cutting edge.