Temperature Dependence of Thermal Expansion Coefficient and Bi-axial Modulus of arc-ion Plated Tin, Crn, Cr₂N and AlTin coations

Abstract

The temperature dependence of metal nitride thermal stress was measured up to 500°C using a high-temperature thin film stress system (Tencor F2400), and primary results for TiN, CrN, Cr₂N, and AlTiN were presented. A series of metal nitrides-TiN, CrN, Cr₂N and AlTiN -were deposited by cathodic arc-ion plating onto Ti-6Al-4V and SUS304 substrate. The temperature dependence of the thermal expansion coefficient and the bi-axial modulus of these coatings were calculated from the temperature-stress relationship for coating deposited onto substrates having different thermal expansion coefficients. Results showed that thermal expansion coefficients of these coatings were monotonically increased as temperature increased up to about 500°C. Of these, Cr₂N and AlTiN are largest at about 9.5×10^-6/°C at room temperature. The biaxial modulus showed slight temperature dependence for all coatings, but different for each coating. The room-temperature biaxial moduluses of TiN, CrN, Cr₂N, and AlTiN are 420, 320, 290 and 500GPa. Using there results, the stress-temperature relationship of TiN, CrN, and Cr₂N which were deposited onto SKD61 and Ti-6Al-4V substrate were calculated.