METHOD FOR MAKING BLANKS OF POWDERS OF REFRACTORY ALLOYS Russian patent published in 2004 - IPC

FIELD: production of blanks of powders of refractory nickel alloys having high resistance against oxidation and used in condition of heavy loads. SUBSTANCE: method for making sintered blanks of powders of refractory alloys comprises steps of pouring powder into capsule; stepwise heating powder until sintering temperature and sintering it; hot plastic working and further stepwise heat treatment of powder. Heating until sintering temperature is realized in next modes: heating until 350 - 400C for time period no more than 20 - 40 min; heating from 350 - 450 C until 750 - 850 C at rate up to 40 C/min; soaking at 750 -850 C for 1.5 - 3 hours; heating until temperature [Ts - (10-30)]C, where Ts - solidus temperature of refractory alloy, and soaking for 0.3 - 0.5 h; heating until temperature of liquid-phase sintering equal to [Tl - (10-50)]C, where Tl - liquidus temperature of refractory alloy, at rate up to 50C/min; soaking at temperature of liquid-phase sintering for time period 20 - 60 min; cooling to 800 - (Ts-10)C and soaking at such temperature for 4 - 6 h. EFFECT: production of blank with optimal macro- and microstructure. 10 cl, 1 ex