6533b7dafe1ef96bd126f438

RESEARCH PRODUCT

Wear of Ceramic Tools When Working Nickel Based Alloys

subject

description

In order to improve the toughness of alumina materials, various trials have recently been made. These include toughening by the addition of zirconia and of significant amounts of titanium carbide to ceramic oxide Al2O3 and the more recent use of nitride based ceramics, which have resulted in an increase of fracture toughness and in a significant improvement of ceramic tool performance. Another very recent way of improving ceramic materials consists in adding SiC whiskers to Al2O3 matrix. This composite material is also suitable for machining nickel based alloys. In order to evaluate and to qualify these materials some test cycles have been carried out in continuous cutting conditions, employing cutting parameters chosen following an experimental design and suitable testing. The wear tests have been carried out on an AISI 310 steel tube, with cutting speeds ranging from lm/s to 4m/s, using as cutting tools silicon nitride, alumina based and mixed-base alumina, alumina reinforced with SiC whiskers and sintered carbide. Their chemical stability, together with their good mechanical properties can explain the appreciable results obtained with sintered carbide and alumina reinforced with SiC whisker tools for the cutting parameters and tool geometry utilised.