Application of Chromium-based Nitride Films to Cutting Tools.

通过在二元氮化物薄膜中掺入第二金属制备了亚稳态PVD薄膜，旨在获得优异的机械性能和摩擦学性能。阴极弧法是一种制备在稳定热力学条件下无法合成的亚稳态三元薄膜的专门方法。在2004-2006年的这一系列研究中，通过X射线衍射和扫描电子显微镜的相变分析，研究了陶瓷氮化物薄膜的最大硬度。当X=0.6时，Ti_&lt；1-x&Gt；Al_xN的晶体结构由NaCl型转变为纤锌矿型，而Ti_&lt；1-x&Gt；CrxN和Ti_&lt；1-x&Gt；ZrxN的晶体结构在所有X值都保持了氯化盐型。Crlt；1-x&Gt；AlxN和Zr&lt；1-x&Gt；AlxN的显微硬度在相界处达到最大值，此时薄膜具有一些特殊的晶体和非晶态混合组织。在(Ti，Al)N薄膜中添加铬使Al的最大溶解度增加到73at.%，没有六方相偏析。研究了热退火法制备的立方TixCryAlZn薄膜的相变、晶格参数和显微硬度。即使在800℃时，它们仍保持立方结构。薄膜的点阵参数比室温下降低了0.5%。最后，通过900℃以上的热扩散过程，立方相部分转变为六方相，降低了显微硬度。

Metastable PVD films have been developed by incorporating second metals to binary nitride films in aims a gaining excellent mechanical and tribological properties. The cathodic arc method is a specialized method in creating metastable ternary films which cannot be synthesized under stable thermodynamic conditions. In this series of study, 2004-2006, the maximum hardness of ceramics nitride films was investigated based on the phase transition analyzed by X-ray diffraction and scanning and transmission electron microscopy.Ternary nitride films had higher microhardness than the binaries and had their own maximum hardness at certain values. The crystal structures of Ti_<1-x>Al_xN changed from the NaCl-type to Wurtzite-type at the X=0.6, while the structures of Ti_<1-x>Cr_xN and Ti_<1-x>Zr_xN retained the NaCl-type for all X values. The maximum microhardness of Cr_<1-x>Al_xN and Zr_<1-x>Al_xN were obtained at phase boundary, where films had had some special microstructure with the mixture with crystal and amorphous. Addition of Cr atoms to (Ti, Al) N films expanded maximum Al solubility up to 73 at.% without hexagonal phase segregation. The cubic Ti_xCr_yAl_zN films obtained by thermal annealing were investigated with respect to phase transition, lattice parameter and microhardness. They were kept cubic type even up to 800℃. The lattice parameter of films at decreased by 0.5% compared with to that of room temperature. Finally, cubic phase was partially transformed into hexagonal phase through the thermal diffusion process over 900℃, which decreased its microhardness.