Development and Tensile Properties Evaluation at Room Temperature of Thermal Stress Relaxation Type Ni/PSZ Functionally Graded Materials

Abstract

Using a bonding material of metal and ceramics for heat-resistant materials, large thermal stress is caused by a difference of the coefficient of thermal expansion between metal and ceramics. The functionally graded materials, FGMs could relax the thermal stress. Heat resistance testing for FGMs has been conducted, but a tensile test has not been done. We use powder injection molding, PIM method to fabricate 9-layer Ni/PSZ system FGMs. The purpose of this study; 1) Fabrication of FGMs without warping. 2) Evaluation of tensile properties of FGMs and single sintered body. The conclusions of this study are as follows; 1) The warping of FGMs decreases with increasing load applied to the specimen during sintering. However, cracks occur on the Ni-0 surface. 2) Tensile stress of FGMs decreases rapidly because of breaking the PSZ rich layer.