MATERIAL CHARACTERISTICS AND CUTTING PERFORMANCE OF TIN-AL2O3 CERAMICTOOL

With the objective of producing a ceramic tool for hardened steel cutt ing that is 10% the price of cBN sintered tool but with equal cutting performance, a TiN-Al2O3 ceramic tool was developed in which Al2O3 par ticles are dispersed throughout a matrix that uses TiN as the principa l component. When bearing steel (SUJ2, HRC60) is cut, a TiN-Bl(2)O(3) ceramic tool that is 40vol% Al2O3 particles produces 25% less flank we ar than does a cBN sintered tool. Furthermore, by the time the flank w ear land width V-B reaches 0.2 mm, the surface roughness of the cBN si ntered tool worsens to 4.0 mu mRmax; however, that of the TiN-Al2O3 ce ramic tool is maintained at a value better than 2.5 mu mRmax. Also, in vestigation of the residual stress in the machined work found no diffe rence between the TiN-Al2O3 ceramic tool and cBN sintered tool. Even i f a cBN sintered tool were to be substituted with a TiN-Al2O3 ceramic tool, no problem would generate in the residual stress df cutting surf ace.