Mechanical Properties of TiB₂–Al₃Ti and TiB₂–(Al,Ni)₃Ti Composites

Abstract

Composites of TiB₂-tetragonal Al₃Ti and TiB₂-cubic (Al,Ni)₃Ti have been fabricated using spark plasma sintering method at the temperature between 1173 and 1573 K. When TiB₂–(Al,Ni)₃Ti specimens were sintered between 1273 and 1373 K, (Al,Ni)₃Ti filled in space between TiB₂ grains and dense samples were obtained. On the other hand, when TiB₂–(Al,Ni)₃Ti specimens were sintered at above 1473 K, (Al,Ni)₃Ti evaporated and monolithic TiB₂ were obtained. A similar results have been obtained for the TiB₂–Al₃Ti composites. The highest bending strength of TiB₂–(Al,Ni)₃Ti specimens were 660 MPa obtained for TiB₂–30 mass%(Al,Ni)₃Ti sintered at 1373 K. The highest bending strength of TiB₂–Al₃Ti composites were 610 MPa obtained for TiB₂–30 mass%Al₃Ti sintered at 1473 K. The Vickers hardness of TiB₂–(Al,Ni)₃Ti composites increased as the sintering temperature increased and the maximum value of 2100 Hv were obtained by the sintering at 1573 K.