Abstract
Sintered binary Ti-Al compacts with various Ti/Al ratios prepared by metal injection molding process were investigated. Powder materials used for this study were pre-alloyed TiAl powders (average particle size:10μm), which compositions were Ti55Al45, Ti52Al48, Ti50Al50, Ti48Al52 and Ti45Al55. The green compacts were debound in air or vacuum(102Pa order). Subsequently, they were sintered at 1648K for 7.2ks in vacuum(10-2Pa).
Sintered densities of the compacts after air debinding were lower than that of the compacts after vacuum debinding for all compositions. Relative sintered densities of Ti55Al45 to Ti48Al52 compacts after vacuum debinding were above 96.5%. A Ti45Al55 compact had lower density(94.5%) than the others. Microstructures of the former were composed of two phases of γ and α2. The latter showed γ-phase only. Lamellar structure was observed in the microstructures of Ti55Al45 to Ti50Al50 compacts. Tensile strength at room temperature of Ti55Al45 to Ti48Al52 compacts were in the range of approximately 350-400MPa. A Ti48Al52 compact had the highest strength in all of the TiAl compacts.
