Ti–6Al–4V (TC4) and Ti–6.5Al–3.5Mo–1.5Zr–0.3Si (TC11) joints were achieved via Ti–37.5Zr–15Ni–10Cu (wt%) filler metal when the brazing temperature was in the range from 950 °C (below β-transus) to 1040 °C (above β-transus) for 10–60 min. The role of brazing parameters in the microstructure evolution as well as mechanical properties of both base alloys and brazed joints was studied. The research analysis suggested that the typical interfacial microstructure was divided into five characteristic zones including reaction phases of α-Ti, β-Ti and (Ti, Zr)₂CuNi. With the holding time prolonged, the sectionalized structure transformed into lamellar Widmanstätten structure in the brazing seam at the temperature of 950 °C, and the optimized shear strength reached 616 MPa at 950 °C for 60 min. Nevertheless, when increasing the brazing temperature to 1000 °C, the joint shear strength tended to be stable as the holding time exceeded 20 min due to the elemental homogenization, and the shear strength reached 627 MPa for the holding time of 20 min. Tensile test results showed that the mechanical properties of both TC4 and TC11 alloys were dramatically degraded at the heat treatment temperature of 1000 °C owning to the drastic grain coarsening and phase transition. Additionally, the plastic strain of TC4/TC11 joint brazed at 1000 °C for 20 min was 1.66%, while that of joint brazed at 950 °C for 60 min reached 2.01%. The variation in mechanical properties of base alloys as well as brazed joints under different thermal conditions revealed that the optimized temperature for brazing of titanium alloys was lower than β-transus with a long time.

中文翻译：

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Ti-6Zr-Ni-Cu钎料钎焊Ti-6Al-4V和Ti-6Al-3.5Mo-1.5Zr-0.3Si接头的相变，组织演变和力学性能

当钎焊温度在室温下时，通过Ti-37.5Zr-15Ni-10Cu（wt％）填充金属实现了Ti-6Al-4V（TC4）和Ti-6.5Al-3.5Mo-1.5Zr-0.3Si（TC11）接头。温度范围为950°C（低于β-transus）至1040°C（高于β-transus）持续10-60分钟。研究了钎焊参数在基础合金和钎焊接头的组织演变以及力学性能中的作用。研究分析表明，典型的界面微观结构分为五个特征区域，包括α-Ti，β-Ti和（Ti，Zr）_2的反应相。铜镍 随着保温时间的延长，在950°C的温度下，钎焊缝中的层状组织转变为片状Widmanstätten结构，在950°C的条件下60分钟的最佳剪切强度达到616 MPa。但是，将钎焊温度提高到1000℃时，由于元素均质化，超过20分钟的保持时间，接头剪切强度趋于稳定，在20分钟的保持时间内剪切强度达到627MPa。拉伸试验结果表明，由于剧烈的晶粒粗化和相变，TC4和TC11合金的机械性能在1000°C的热处理温度下均显着降低。此外，在1000°C钎焊20分钟的TC4 / TC11接头的塑性应变为1.66％，而在950°C钎焊60 min的接头焊缝率达到2.01％。在不同的热条件下，基础合金以及钎焊接头的力学性能的变化表明，长期以来，钛合金钎焊的最佳温度低于β-转变温度。