Molybdenum News Center

TZM Alloy Strengthening Ways

TZM alloy has three strengthening mechanism, which is solid solution strengthening and second phase strengthening caused by titanium, zirconium, carbon and deformation strengthening caused by subsequent processing of produce. However, there are other strengthening ways, such as adding rhenium, carbide, rare earth oxides, staple fibers and neutron radiation and so on. These methods can improve alloy’s properties.

Rhenium Elements Strengthening

Doped alloying elements in TZM alloy will great improvement molybdenum brittleness and improve the performance of the alloy. Besides, doped rhenium in the alloy, not only can improve the high temperature properties of the alloy, and can significantly improve the properties of the alloy at room temperature. Rhenium occur solid solution reaction with the molybdenum substrate to form toughness and dense solid solution crystal structure. During bending fracture, molybdenum-rhenium solid solution is mainly transgranular fracture. And molybdenum-rhenium solid solution absorbs a lot of breaking energy can effectively improve the properties of the alloy at room temperature. However doped rhenium in alloys can inhibit titanium, zirconium solid solution in molybdenum, resulting in a large number of pores and a second phase particles gathering in rhenium-molybdenum alloy grain boundaries, which have an adverse effect on the strength of the alloy.

Rare Earth Oxide Strengthening
Doped with rare earth oxides in TZM alloys is in favor of grain refinement, and with doped quantity of rare earth oxides increase, the grain refining effect is more obvious. The common rare earth oxide is La₂O₃. Doped a certain amount of La₂O₃ particles in the alloy, these particles will also evenly distributed in the grain boundary and grain, so that the toughness of TZM alloy has been significantly strengthened.

Neutron radiation strengthening
In the range of 25 ~ 450 ℃ TZM alloy after neutron irradiation, the elongation sharp declines, but the breaking strength increases with test temperature increases. In addition, the alloy at 700 ℃ neutron radiation, a significant increase in yield strength, but the temperature exceeds 700 ℃, its strength did not change significantly.

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