Effects of heat treatment on the mechanical property and corrosion behavior of PT-7M titanium alloy

The effects of heat treatment on the mechanical property and corrosion behavior of PT-7M titanium alloy have been evaluated. The alloy was heat -treated in the temperature range of 500 to 1000 .deg. C for 1hr, and water quenched. Tensile test results indicated that there was little effect of the α heat-treatment (from 500 to 900 .deg. C) on the strength and ductility of this alloy whilst there was a considerable reduction of the strength and ductility in the alloy heat-treated at the β-Ti phase region (1000 .deg. C). The hardness test results revealed that there was little effect of the α heat-treatment on the hardness values whilst the β heat-treatment induced a significant increase of the hardness values in this alloy. It would be mainly attributed to the microstructure change by the β heat-treatment. Corrosion test results at 360 .deg. C in an ammonia aqueous solution of a pH 9.98 showed that the α heat-treatment of this alloy induced a significant reduction of corrosion resistance. It would be mainly responsible for the enlargement of precipitate size