DEEP DRAWING OF MOLYBDENUM AND ITS ALLOYS
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
The effect of various technological factors on the capacity for deep drawing of commercial-grade sintered molybdenum and TaM-2 and Vm-1 molybdenum alloys has been investigated on flat specimens, 6mm wide and 0.5 and 0.8mm thick, cut from rolled sheets in the direction alone, andor transverse, or at a 45 deg. angle to the direction of rolling. Test specimens in the annealed or strain-hardened condition were tested for mechanical properties under conditions of uniaxial and biaxial tension at temperatures of up to 500C. Except for recrystallized sheet, the NDT temperature of all the investigated material was below room temperature. This showed that satisfactory parts can be produced from them by drawing at room temperature. The capacity for deep drawing depended mainly on the content of impurities, the microstructure and the deformation rate. Heating to 100-120C significantly decreased the susceptibility to exfoliation and cracking and appreciably extended the technological use of the investigated metals. The capacity of sheet molybdenum for deep drawing increased with increasing prestraining at cold or warm rolling. The experimental results showed also the feasibility of progressive multioperation deep drawing of thin wall parts from molybdenum and molybdenum- alloy sheets, with or without intermediate stress relieving. Depending on the sheet thickness, the direction of rolling and the heat treatment prior to drawing, the optimum temperature of drawing was within 220 to 350C.
- Properties of Metals and Alloys
- Fabrication Metallurgy