Properties of the sintered TiAl compacts prepared by injection molding

摘要

Properties of the sintered TiAl compacts by applying a metal injection molding(MIM) process to various type of pre-alloyed powders by SHS-crash method were investigated. Results obtained are as follows:1) Test pieces of Ti-50at%Al intermetallic compounds were prepared under various process conditions; size and shape of powder, debinding condition, and sintering temperature. When fine spherical-treated powder (average particle size: 10μm) was used，sintering reaction proceeded rather readily， and then the compacts was more dense and more tough ( >400MPa) than the case of coarse powder.2) Properties of binary sintered compacts with various Ti /Al ratios (45,48,50,52, and 55at%) were investigated. The compacts except 55at%Al had the relative densities more than 96% and the tensile strength of about 400MPa at room temperature. Tensilestrength of 45.48 and 5Oat%Al compacts at 800°C were almost equal to the strength of those at room temperature. The strength of those compacts at 1000°C, however, went down to about 200MPa.3) Properties of ternary sintered compacts (Ti-48A1- 2Mo,Ti-50Al-2Mo,Ti-48A1-2Mn, Ti-50Al-2Mn, Ti-48A1-2Cr) were investigated. All compacts had the relative densities more than 95% Ti-rich compacts (Ti-48A1-2Mo, Ti-48A1-2Mn, Ti-48A1-2Cr) had finemicrostructures to the binary. Ti-48A1-2Mo compact had the strength of 470MPa. The ductility of ternary compacts at room temperature was lower than that of binary one.