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采用现有RDL-50型拉伸蠕变试验机,改装部分试验装置后研究Ag In Cd合金加Sn前后在300~400℃温度及12~30 MPa应力范围内的压缩蠕变行为。根据试验结果详细分析稳态速率与温度、应力的关系,计算应力指数n和蠕变激活能Qa;并根据透射电子显微镜结果探讨合金的压缩蠕变机制。结果表明:随温度和应力水平的升高,合金的稳态蠕变速率增加。加Sn后,Ag In Cd对应力敏感性更大,且在任一应力下激活能更高,其抗蠕变性能较好。根据计算,300、350、400℃条件下,加Sn与不加Sn合金的蠕变应力指数n分别为9.41、8.07、9.48和3.31、4.10、5.77;12、18、24 MPa条件下,加Sn与不加Sn合金的蠕变激活能Qa分别为147.9、126.9、149.9 k J/mol和68.1、103.7、131.6 k J/mol。微观形貌以层错为主,300℃的主要蠕变机制为孪生,400℃的主要蠕变机制为位错攀移生成位错墙。
The existing RDL-50 tensile creep testing machine was used to study the compressive creep behavior before and after the addition of Sn in Ag In Cd alloy at 300-400 ℃ and stress range of 12-30 MPa. According to the experimental results, the relationship between steady-state rate and temperature and stress is analyzed in detail, and the stress index n and the creep activation energy Qa are calculated. The compression creep mechanism of the alloy is discussed based on the transmission electron microscopy results. The results show that with the increase of temperature and stress level, the steady creep rate of the alloy increases. After adding Sn, Ag In Cd is more sensitive to stress and has higher activation energy under any stress, and its creep resistance is better. According to the calculation, under the conditions of 300, 350 and 400 ℃, the creep stress exponent n of Sn with and without Sn is 9.41,8.07,9.48 and 3.31,4.10,5.77, respectively. Under the conditions of 12,18 and 24 MPa, Sn The creep activation energies Qa and 147a, 96.9 and 149.9 kJ / mol and 68.1, 103.7 and 131.6 kJ / mol, respectively, for the alloy with and without Sn addition. The microstructure is dominated by layer faults. The main creep mechanism at 300 ℃ is twins, and the main creep mechanism at 400 ℃ is dislocation climbing to generate dislocation walls.