Ti-30Zr-5Al-2.5Sn (TZAS, wt. %) is a novel α-type Ti-Zr based alloy. Herein, the effect of phase and microstructure evolution on mechanical properties of hot-rolled TZAS alloy with mixed α and α′ martensite phase were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy and statistical analysis. The content of primary α phase decreased as the hot-rolling temperature increased from α to α+β region. When the rolling temperature increased to 875 °C, the predominant phase transformed from α phase to α′ martensite phase. The spheroidization degree of TZAS alloys increased with rolling temperature until 850 °C. As the rolling temperature increased from 775 °C to 825 °C, the yield strength gradually enhanced, attributing to the synergistic effect of grain-boundary strengthening, dislocation strengthening and second-phase strengthening from martensite. While, as further increase of rolling temperature, the coarsen primary α grains led to the decrease of yield strength. A peak yield strength of 1038 ± 26 MPa and total elongation of 14 ± 0.6% were obtained after rolling at 825 °C. One should note that work hardening was also a key factor for the alloys strengthening. Furthermore, the fracture mechanisms of studied alloys were also discussed in depth.

Ti-30Zr-5Al-2.5Sn（TZAS，wt。％）是一种新型的α型Ti-Zr基合金。在此，通过光学显微镜，扫描电子显微镜，透射电子显微镜和统计分析研究了相和组织演变对具有α和α'马氏体混合相的热轧TZAS合金力学性能的影响。随着热轧温度从α到α+β区域的增加，初生α相的含量降低。当轧制温度升至875°C时，主要相从α相转变为α'马氏体相。TZAS合金的球化度随轧制温度的升高而提高，直至850°C。随着轧制温度从775°C升高到825°C，屈服强度逐渐增强，这归因于晶界强化的协同作用，马氏体的位错强化和第二相强化。同时，随着轧制温度的进一步升高，粗大的初生α晶粒导致屈服强度降低。在825°C下轧制后，可获得1038±26 MPa的峰值屈服强度和14±0.6％的总伸长率。应该注意的是，加工硬化也是合金强化的关键因素。此外，还深入讨论了研究合金的断裂机理。