Molybdenum News Center

TZM Alloy Strengthening Mechanism

TZM alloy is an important molybdenum alloy. It is widely used in many different fields. Comparing with pure molybdenum, TZM alloy has better performance. TZM alloy based on molybdenum matrix doped with Ti, Zr, C and other trace elements, and these elements will react with molybdenum (Mo) to produce solid solution strengthening and second phase strengthening. These strengthening mechanism can improve TZM alloy high temperature property and mechanical property. The following major analyze TZM alloy strengthening mechanism, including solid solution strengthening, and second phase strengthening deformation strengthening.

Solid solution strengthening means Ti, Zr and C atoms into the crystal lattice of molybdenum, distorting the lattice distortion, while strengthening effect produced. The large atomic element difference factor between solvent and solute elements is, the greater strengthening effect is showing. In the solid solution strengthening, Zr and Mo have largest atomic size factor difference, so the effect is most obvious.

The second phase strengthening refers doped trace elements react with C to form insoluble fine carbide particles. These particles are dispersed distribution at grain boundaries of TZM alloy. They can stabilize forging structure and impede dislocation motion, so that the alloy gets strengthened. Researchers believe that the mass ratio of (Ti + Zr) and C at 4~10 is the best. On the other hand, during production TZM alloy should more stringent control C content, preventing to produce Mo2C, reducing the mechanical property of the alloy.

Deformation strengthening, namely, work hardening, with the plastic deformation of the alloy increase, the strength of the metal flow also increased. TZM alloy under recrystallization temperature, deformation strengthening effect will increase with deformation enhance. TZM alloy grain along the machine direction elongation occur lattice distortion during deformation, so that the dislocation density increases, secondary grains produced, thereby increasing the strength of the alloy.

• < Prev
• Next >