Molybdenum News Center

TZM Alloy High Temperature Mechanical Properties Affected by TiC and ZrC Doping Quantity

In the high temperature, TZM alloy can be affected by heat, and reduce the binding force between the atoms, causing "softening" effect at high temperatures and reducing alloy’s high temperature mechanical properties. Testing undoped carbide alloy and doped with TiC / ZrC alloys found these three alloys tensile strength at 800 ℃ is lower room temperature tensile strength. Compared with room temperature tensile strength, doped with 0.4% TiC alloy at 800 ℃tensile strength is decrease by 22.4%. Doped with 0.4% ZrC alloy compare with room temperature is decrease only 16.1%. However, Undoped carbides alloy tensile strength decline fast, down by as much as 27.7%.

Carbide content has a certain influence on alloy’s strength. With the carbide quantity increase, alloy strength has been significantly improved. At 800 ℃, doped 0.4% TiC alloy, the tensile strength is 450.5MPa, compared with undoped carbides alloy is increase 28.3%. Alloy doped with 0.4% ZrC, the tensile strength at 800 ℃ is about 513.4MPa, compared with carbides free alloy increases 56.7%.

TZM alloy which doped with small amount of carbide room temperature tensile exhibits elastic deformation, followed by obvious plastic deformation and fracture. Alloy which undoped with carbide after elastic deformation is fracture, indicating carbide can improve alloy room temperature brittle. On the other hand, doped with 0.4% TiC / ZrC alloy has obvious yield phenomenon at 800 ℃. Observing from the micrograph there is significant upper and lower yield point and the yield plateau, having large fracture strain. Indicating doped with carbide alloy can has higher elongation. This is mainly because TiC or ZrC can interact with solute atoms and dislocations to form Cottrell air mass, so that the dislocation is stability. Dislocation motion to get rid of the Cottrell air mass pinning effect need for greater stress, but once it break the movement of dislocations is easier, which appeared in the upper and lower yield point and the yield plateau.

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