Effects of Purity of Titanium Powder and Porosity on Static Tensile Properties of Sintered Titanium Specimens

Using two different kinds of titanium powders, some properties of P/M titanium specimens were investigated in relation to porosity. Hunter-process sponge fines showed a better compressibility than Kroll-process HDH titanium powders, but the sintered density ratio of the former became nearly the same as that of the latter due to the poorer shinkage during sintering. Both tensile strength and elongation of the sintered HDH titanium powder specimen increased nearly in proportion to the increased sintered density ratio, while in the sintered Hunter-process sponge fines specimen, there existed a flat region where both of the above mentioned static tensile properties were nearly constant independently of sintered density ratio. In the fracture surface of the sintered Hunter-process sponge fines specimen after static tensile test, there appeared non-metallic inclusions, which were identified as NaCl crystal by energy dispersive spectrum analysis.