Study of the mechanical properties of molybdenum alloyed with hafnium

Abstract

The mechanical properties of Mo-base alloys containing 0.2, 0.5, and 1.0 wt. percent Hf were investigated at 20 to 2000/sup 0/C. It was found that at the test temperatures used, all the alloys of molybdenum with hafnium possess a higher short-term strength than does unalloyed molybdenum. At temperatures up to 500/sup 0/C the strongest alloy is that containing 0.2 wt. percent Hf (the strengthening being greater if the hafnium is in the oxidized state); above 1250/sup 0/C the alloys become stronger with increase (0.5 to 1.0 wt. percent) in hafnium content (strengthening being greater if the hafnium is in the unoxidized state). In the temperature range 1250/sup 0/C to 1500/sup 0/C the ductility of molybdenum and its alloys with hafnium is heightened probably as a result of recrystallization processes taking place in the course of the tests.