A study of hot deformation behavior and microstructural characterization of Mo-TZM alloy

Hot compression testing of Mo-TZM (Mo-0.5Ti-0.1Zr-0.02C) alloy was carried out between 600 and 900 deg. C employing strain rates from 0.001 s-1 to 1 s-1. Both the constant strain rate and strain rate change test results showed that Mo-TZM possesses low strain rate sensitivity in this temperature range. Activation energy calculated by using strain rate change data and plotting temperature compensated strain rate (Z) vs. shear modulus corrected flow stress (σ/G) was found to be 290 kJ/mol. Electron back scattered diffraction (EBSD) and transmission electron microscopic (TEM) results obtained from the rapidly cooled deformed specimens revealed the formation of subgrains. Flow stress-plastic strain results and misorientation angles between subgrains showed an anomalous behavior at 800 deg. C.