Molybdenum News Center

Different Compression Ratio Affected TZM Alloy Plate Tensile Fracture

Observed 40%, 60%, 82% and 90% compression rate the TZM alloy plate tensile fracture morphology found as the compression ratio increases, the degree of densification is increase and the fracture mode change from the intergranular brittle fracture, intergranular ductile fracture, transcrystalline fracture to transgranular quasi-cleavage fracture.

The un-rollding alloy plate has a lot of voids and the fracture mode is intergranular brittle fracture. Observed the SEM picture can found each grain of alloy mostly is polyhedral shape and filled with voids. In the stretching process, these voids will become a source of cracks, causing fracture, reducing tensile strength.

When the compression rate is 40%, TZM alloy plate tensile fracture morphology is intergranular ductile fracture and cleavage fracture, in which a small number of grains have transgranular fracture phenomenon. There are some voids and small TiC particle. TiC particle showed in the grain boundary will reduce the strength of grain boundary. Further, presented crystal axis organization and voids will reduce the tensile strength of the alloy.

When the compression rate is 60%, the fracture mode is mixed fracture mode which includes quasi-cleavage fracture and transgranular ductile and brittle intergranular fracture. Besides, the dimple is clearly visible and transgranular fracture grains are increase, accompanied with quasi-cleavage fracture characteristics. In addition, the more transcrystalline fracture grains increases, indicating that the grain boundary of the alloy has been some strengthening.

When the compression rate is 80%, the fracture mode is still mixed fracture. However, transgranular fracture and quasi-cleavage fracture grains have further improved. In addition, the fibrous tissue of alloy is increase and you can clearly see some tearing ridge and shallow small dimple, which mainly occurs in plastic deformation of quasi-cleavage fracture. The alloy presented quasi-cleavage fracture has higher fracture toughness property.

When compression ratio is 90%, TZM alloy plate showing obvious quasi-cleavage fracture and transgranular fracture, most grain showing transgranular fracture. Further, since plastic deformation occurs in the grains and the cracks and voids are crushed and welded, so the welding and voids on the fracture have significantly decrease, which can enhance the strength and cohesion of the alloy, improving alloy’s mechanical properties.

• < Prev
• Next >