Abstract
In traditional physical metallurgy,once recrystallization occurs,it will proceed to 100％along with time even at relatively low temperatures,resulting in the limited thermal stability of partially recrystallized al-loys.Here,we proposed the strategy of achieving the endless recrystallization state at high temperature(～0.6Tm)in high entropy alloys for the first time.The partially recrystallized microstructures remained stable after annealing at 700℃ for 1440 h toward endless recrystallization with kinetics analysis.Ben-efiting from the ultra-thermostable heterostructures,the alloy exhibited excellent mechanical properties of～1.6 GPa tensile strength at room temperature and～1.1 GPa tensile strength at 600℃ even after exposure at 700℃ for 720 h.The kinetics of recovery,recrystallization,grain growth,and precipitate coarsening were quantitatively analyzed to uncover the mechanisms of endless recrystallization.The re-sults revealed that the stable state of 50％recrystallization at 700℃ can be attributed to the precipitates inhibited recrystallization and the continued recovery decreased stored energy in the non-recrystallized regions.Furthermore,the grain size was stable in the recrystallized regions due to the strong pinning ef-fect of the intergranular precipitates with slow coarsening rates.These findings created a brand-new state of endless recrystallization with the combination of recovery and recrystallization,which can significantly broaden the service temperature range of heterogeneous materials.
基金项目
国家自然科学基金(51771149)
国家自然科学基金(51871183)
Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX202022)
NETL
NSTL
维普
万方数据