Tensile properties, strain rate sensitivity and failure mechanism of single crystal superalloys CMSX-4

The tensile behavior of single crystal superalloys CMSX-4 was investigated under different strain rates at room temperature. The objective of this study is to identify the strain rate sensitivity and understand the damage failure mechanism by checking stress-strain curves and microstructure of the deformed sample. Experimental results show that the stress-strain curves including strain hardening behavior at both strain rates are different. The size of cleavage facets and dimples in the tensile fracture surface is related to the strain rates. The shearing lines cross through the γ matrix and γ' precipitates, which is related to the movement of dislocations. Then, Schmid factor and the damage failure mechanism during tensile tests are estimated and discussed.