Rapid thermal processing of TiN coatings deposited by chemical and physical vapor deposition using a low-energy, high-current electron beam: Microstructural studies and properties
Aj. Perry et al., Rapid thermal processing of TiN coatings deposited by chemical and physical vapor deposition using a low-energy, high-current electron beam: Microstructural studies and properties, MET MAT T A, 30(11), 1999, pp. 2931-2939
Monolithic TiN coatings deposited onto cemented carbide cutting tool insert
s coated by chemical vapor deposition (CVD) or physical vapor deposition (P
VD) methods, respectively were subjected to pulsed intense electron beam tr
eatments in the energy range 3 to 5 J.cm(-2). The temperature profiles for
this rapid thermal processing (RTP) covered the range between fusion of the
cobalt binder in the carbide to surface fusion of the TiN coatings. The tr
eatment caused extensive cracking in all coatings, removed the atomic level
defects, vacancies and dislocations, and the residual stress in the PVD co
atings, but caused little change in the CVD coatings. There was some nitrog
en loss very close to the surface but no change in the stoichiometry of the
bulk of the nitride. In contrast, no changes were found in the carbide sub
strate below the PVD coatings, but microscopic changes were found immediate
ly below the surface in the carbide under the CVD coatings. Steel turning t
ests suggest that treatment of the PVD coatings at the lowest power used, 3
J.cm(-2), reduced the flank wear by a factor of 2 but had no effect on any
of the CVD coatings.