Design and fabrication of TiC-based symmetrically compositional functional graded materials

Some Aspects of Research on Layered Ceramic Composites in China

“…In a symmetrical layered ceramic, the design of the residual stress is very important, because the inner tensile stress should be as low as possible when a surface compressive stress is introduced. For further improving the properties of TiC-based cermets with the aim to replace more kinds of WC-based cemented carbides, TiC(Mo, Ni)x/TiC(Mo, Ni)y/ TiC(Mo, Ni)x symmetrically compositionally functional graded materials SCFGM are proposed and fabricated, which have the following advantages: (1) more wear resistant surface layers composed of less Ni-Mo alloying in combination with tougher mid-layers composed of more Ni-Mo alloying; and (2) artificial residual compressive stress created on both surfaces of the specimen due to the difference in the thermal expansion coefficient between surface layers and mid-layer s, which remarkably increases the bending strength and the fracture toughness of the SCFGM [14].…”