Method to produce gamma titanium aluminide articles having improved properties

摘要

Gamma titanium aluminide alloy articles having improved properties are produced by the following methods: The first of these methods comprises the steps of: (a) heat treating an alloy billet or preform at a temperature in the approximate range of T alpha to T alpha +100 DEG C. for about 0.5 to 8 hours, (b) shaping the billet at a temperature between T alpha -30 DEG C. and T alpha to produce a shaped article, and (c) aging the thus-shaped article at a temperature between about 750 DEG and 1050 DEG C. for about 2 to 24 hours. The second method comprises (a) rapidly preheating an alloy preform to a temperature in the approximate range of T alpha to T alpha +100 DEG C., (b) shaping the billet at a temperature between T alpha and T alpha +100 DEG C. to produce a shaped article, and (c) aging the thus-shaped article at a temperature between about 750 DEG and 1050 DEG C. for about 2 to 24 hours. The preform is held at the preheat temperature for 0.1 to 2 hours, just long enough to bring the preform uniformly to the shaping temperature. The third method comprises the steps of: (a) heat treating an alloy billet or preform at a temperature in the approximate range of T alpha to T alpha +100 DEG C. for about 0.5 to 8 hours, (b) rapidly heating the preform to shaping temperature, if the shaping temperature is greater than the heat treatment temperature, (c) shaping the preform at a temperature between T alpha and T alpha +100 DEG C. to produce a shaped article, and (d) aging the thus-shaped article at a temperature between about 750 DEG and 1050 DEG C. for about 2 to 24 hours. The fourth method comprises the steps of: (a) heat treating an alloy billet or preform at a temperature in the approximate range of T alpha -40 DEG C. to T alpha to for about 0.1 to 2 hours, (b) rapidly preheating the preform to shaping temperature, (c) shaping the preform at a temperature between T alpha and T alpha +100 DEG C. to produce an shaped article, and (d) aging the thus-shaped article at a temperature between about 750 DEG and 1050 DEG C. for about 2 to 24 hours.