Fabrication and Mechanical Property of W-Y₂O₃ Composites and Graded material

W-Y 2 O 3 composite with the gradient variation of volume content of Y 2 O 3 was fabricated by pressureless sintering process. Phases and microstructure of W-Y 2 O 3 composite were characterized. Fracture mechanism was explored by means of the measured results of mechanical properties and fracture morphology. Distribution of thermal stress in W-Y 2 O 3 graded material during sintering is simulated by finite element method, while feasibility of composition content and structure of each layer are analyzed, then W-Y 2 O 3 graded material is successfully fabricated by this process. The results show that the mechanical properties of W-Y 2 O 3 composite decrease with the increment of volume content of Y 2 O 3 , which is mainly contributed to the effects of inherent strength of composed phase, porosity and grain size. Finally, faultless W-Y 2 O 3 graded material with high quality of interface bonding can be fabricated by reasonable design of gradient layers.