Hot deformation behavior and microstructure evolution of flaky Ti₃AlC₂ particles reinforced pure Al composite

Optimizing the hot working parameters of metal matrix composites is beneficial for improving the microstructure of the matrix and the distribution of the reinforcements and eliminating materials defects. In this work, the hot deformation behaviors of the 20 vol% flaky Ti₃AlC₂ particles reinforced pure Al composite at strain rates of 10⁻³–1 s⁻¹ and temperatures of 350–500 °C were investigated by hot compression tests. Friction correction equations were used to correct the flow stress data. The constitutive equations and processing maps were successfully established. The flow stresses of the Ti₃AlC₂/Al composite were precisely described through the hyperbolic sine constitutive equation. The true stress exponent was calculated to be 8, similar to the creep process with invariant microstructure. The particle rotation caused by the deformation of the Al matrix led to the alignment of the Ti₃AlC₂ flakes. The optimum hot working parameters of the composite are in the range of 410–500 °C, 0.18–1 s⁻¹ based on the processing maps. Dynamic recrystallization (DRX) had a higher proportion in the optimum safe region. The high temperature-low strain rate unstable region was associated with superplastic. The instability in the low temperature-low strain rate region stemmed from the interface microcracks generated by the rotation of Ti₃AlC₂ flakes. The processing map theory can be well correlated with the microstructure evolution of the composite under different deformation parameters.