Method of preparation by metallurgy of the powders of pieces in molybdenum or an alloy of molybdenum

摘要

P the invention relates to a method of preparation by powder metallurgy of parts made of molybdenum or an alloy of molybdenum. / p & & p & this method consists of: a. by preparing a powder of molybdenum or molybdenum alloy of a particle size greater than 100 mu and having a content of o2 at most equal to 100 ppm; b. to introduce under vacuum or under an inert atmosphere, the said powder in a sheath made of a material having a temperature of less than 1 250°C, the ductility at least equal to that of the molybdenum or of the alloy of molybdenum, said material is not capable of reacting with the molybdenum or the alloy of molybdenum at said temperature, to be packed, under vacuum or under inert atmosphere, the powder in the sheath and to close off under vacuum or under an inert atmosphere, said sheath; c. a sheathed subjecting the assembly thus obtained to an operation of drawing or rolling at a temperature less than 1 250°C, and d. to subsequently remove the sheath in order to obtain a part made of molybdenum or an alloy of molybdenum. / p & & p & application to the embodiment of the tubes of molybdenum. / p