材料期刊网

Ti_3X相是影响钛合金热稳定性的重要因素。Ti_3X相沉淀和生长的倾向可用电子浓度值来描述。同时,合金脆化过程与暴露温度和时间因素有关。因此,可综合电子浓度,使用温度和时间因素加以考虑,确定一个允许的电子浓度值_p作为一个合金的热稳定性判据。热稳定性判别式可表示为∑N_if_i~a≤_p。 判据具有明确的物理意义,它可以用作合金生产的质量控制标准和新的合金设计依据。 若以合金元素对电子浓度的贡献来确定各合金元素的Al当量因子,则Rosenberg的经验Al当量公式应修改为1(％Al)+0.46(％Sn)+0.42(％Ga)+6.7(％O)≤8(wt-％)。

The Ti_3X-phase is found to be an important factor influenced the thermal stability of Ti alloys. The tendency towards the precipitation and growth of Ti_3Xphase may be described as the value of electron concentration. A kinetics of the embrittlement process of the alloys, depending on the exposure temperature and time, has been confirmed. Taking three factors, including electron concentration, operating temperature and service time, into account, a permissible electron concentration, N_p, may be ascertained as criterion for the thermal stability of an alloy. The physical meaning of the criterion is definite. A proposal could be made that the criterion is available for the standard of quality control of the alloy production and in new alloy design. If the determination of the Al equivalent factors of various alloying elements was made by their contribution to electron concentration, the Rosenberg's empirical formula should be modified as follow: 1(％Al)+0.46(％Sn)+0.42(％Ga)+6.7(％0)≤8(wt-％)