Abstract
TiNi shape memory alloy was fabricated by powder injection molding, and tensile and recovery stress tests were carried out on the alloy. The effects of sintering conditions on the microstructures and mechanical properties of the sintered alloy were investigated. Ti gas-atomized powder and carbonyl Ni powder mixed well with polyamide binder and injection-molded into a mold for tensile test specimens. The injection-molded compacts were debound at 593 K and then sintered at 1173 K, 1223 K and 1423 K for various sintering times. The density and microstructure of the sintered compacts were influenced greatly by the sintering temperature. The tensile strength and elongation of the sintered compacts were much less than those of the same alloy made by spark-plasma sintering, because the density of the former were much lower than that of the latter. The obtained alloy, however, showed apparent shape memory effect.
