Mechanical properties of Al2O3/TiC/Ni FGMs doped with WC/Co
Tanihata Kimiaki; Qin Jining; Lin Junshan; Miyamoto Yoshinari; Yamamoto Masafumi; Yarii Toshio; Tanaka Ryohei
Abstract:The Al2O3 WC-Co/TiC/Ni/TiC/Al2O3 WC-Co FGMs with a symmetrically graded structure were fabricated by SHS/HIP. It is possible to induce the strong residual compressive stress in the outer ceramic layers of the ceramic/metal/ceramic symmetric FGMs due to the thermal expansion mismatch between the outer and inner layers. The doping of WC-Co into the outer Al2O3 layers further increased the residual stress comparing with the Al2O3/TiC/Ni/TiC/Al2O3 system. The toughness and the strength of the outer layer increased to 13.1 MPam1/2 and 950 MPa by doping 20 vol% of WC-Co, respectively. Stress analysis was carded out for the macro and micro structures of FGMs by means of X-ray diffraction method and finite element method. The correlation between the surface stress and the mechanical properties was discussed. Key Words:Al2O3-WC-Co.TiC/Ni/TiC/Al2O3-WC-Co, symmetrically graded structure, residual compressive stress, WC-Co dopants, stress analysis by FEM