2. Molybdenum Alloys In contrast to the other bcc refractory metals – molybdenum is a relatively abundant material in the Earth’s crust – and reasonable quantities of fine grained material can be prepared by consumable electrode melting – or by powder metallurgy followed by sintering.

3. Molybdenum Alloys Mo and W form a continuous series of solid solutions and the resultant solution strengthening increases the degree of strain hardening that can be obtained by cold work Ti and Zr are added to form a fine dispersion of carbides in order to restrict the recrystallization of Mo – so that strain hardening can be retained to higher temperatures Mo-5Re and Mo-41Re alloys have been developed for improved high-temperature strength but such alloys are not regarded as cost effective at the present time – as Re is a relatively scarce and expensive metal

4. Microstructure of Mo Alloys Fine grained structure of Mo prepared by powder metallurgy and sintering

5. Effect of Temperature on UTS of Mo Alloys As the basis of dispersive strengthening is the retention of cold work – the advantages of dispersive phase alloying disappear above the recrystallization temperature of 1000-1300 o C – when pure Mo is just as strong Key 1 = TZM cold worked 2 = Pure Mo cold worked 3 = TZM recrystallized 4 = Pure Mo recrystallized

6. The End Any questions or comments?