The effect of indentation temperature and load on mechanical characterization and transformation behavior of high temperature Ti-V-Al-Cu shape memory alloy

The effects of temperature and load on the indentation-induced mechanical characterization of the Ti-V-Al-Cu alloy were investigated. Also, the effects of heating/cooling rate and thermal cycle on the transformation temperatures were examined. Thermally-induced reverse martensite phase transformation was detected from alpha '' martensite phase to beta austenite phase during heating. Transformation temperatures decreased with the heating rate and thermal cycles. High temperature microindentation tests were conducted at both 450 degrees C (>As) and room temperature (24 degrees C) at four different loads to determine indentation-induced mechanical properties and deformation behaviors. The deformation mechanism of the Ti-V-Al-Cu alloy at 450 degrees C was found to involve the stressinduced martensite transformation associated with superelasticity and partially causing transformation from beta phase to alpha '' phase. The superelastic and total recoverable strains are 48% and 62% at 8000 mN load for 450 degrees C and are the highest values obtained for this study. The results show that the effect of load on the deformation mechanism of the same Ti-V-Al-Cu alloy at different temperatures is different and positively affects elastic recovery at 450 degrees C while causing plastic deformation at room temperature.

Automated summary

The study investigated the effects of temperature and load on the indentation-induced mechanical properties of the Ti-V-Al-Cu alloy, finding that transformation temperatures decreased with heating rate and thermal cycles. The effect of load on the deformation mechanism of the alloy at different temperatures was different, positively affecting elastic recovery at 450 degrees C.