Compositions comprising nickel-titanium, methods of manufacture thereof and articles comprising the same
View Patent ↗Disclosing herein is a method for manufacturing nickel-titanium compositions. The method includes disposing a powdered composition in a mold; the powdered composition comprising nickel and titanium; the titanium being present in an amount of about 38 to about 42 wt % and the nickel being present in an amount of about 58 to about 62 wt %; sintering the powdered composition to produce a sintered preform; compacting the preform; machining the preform to form an article; heat treating the article; the annealing being conducted at a temperature of about 1650° F. to about 1900° F. at a pressure of about 3 Torr to about 5 Kg-f/cm 2 for a time period of about 10 minutes to about 5 hours; and quenching the article.
1. A method comprising:
disposing a powdered composition in a mold; the powdered composition comprising nickel and titanium; the titanium being present in an amount of about 38 to about 42 wt % and the nickel being present in an amount of about 58 to about 62 wt %;
sintering the powdered composition to produce a sintered preform, wherein sintering the powdered composition is conducted at a first temperature of about 1800° F. to about 2200° F., a first pressure of about 3 Torr to about 5 Kg-f/cm 2 for a first time period of about 20 minutes to about 180 minutes;
compacting the preform;
machining the preform to form an article;
heat treating the article; the heat treating being conducted at a temperature of about 1650° F. to about 1900° F. at a pressure of about 3 Torr to about 5 Kg-f/cm 2 for a time period of about 10 minutes to about 5 hours; and
quenching the article.
2. The method of claim 1 , wherein the compacting the preform is conducted using hot isostatic pressure compaction.
3. The method of claim 2 , wherein the hot isostatic pressure compaction is conducted at a second temperature of about 1700° F. to about 2250° F., a second pressure of about 2110 to about 11250 Kg-f/cm 2 , and a second time is about 0.5 to about 20 hours.
4. The method of claim 2 , wherein the hot isostatic pressure compaction is conducted at a second temperature of about 1800° F. to about 1900° F., a second pressure of about 4000 to about 8000 Kg-f/cm 2 and a second time of about 2 to about 5 hours.
5. The method of claim 1 , wherein the heat treatment is conducted at a temperature of about 1790° F. at ambient pressure for a time period of 150 minutes.
6. The method of claim 1 , further comprising vibrating the powdered composition prior to the sintering.
7. The method of claim 1 , wherein the powdered composition comprises particles having an average particle size of about 50 to about 150 micrometers.
8. The method of claim 1 , wherein the quenching is conducted in oil.