【摘要】 采用蠕变实验和理论计算,研究了时效态Mg-5Y-3Sm-0. 8Ca-0. 5Sb合金在250～300℃和50～70 Pa条件下的蠕变行为。结果表明,该合金具有良好的抗高温蠕变性能,其在300℃和70 MPa下的稳态蠕变速率为3. 28×10-8s-1。在50～70 MPa的应力下,当温度由250℃升到300℃时,应力指数由2. 30变为3. 22;在250～300℃的温度下,当应力由50 MPa升到70 MPa时,蠕变激活能由65. 4 kJ/mol变为81. 0 kJ/mol。更多还原

【Abstract】 The creep behavior of aged Mg-5 Y-3 Sm-0.8 Ca-0.5 Sb alloy at 250-300 ℃ and 50-70 MPa was investigated by creep tests and theoretic calculation.The results show that the alloy has good high temperature creep resistance and the steady-state creep rate of 3.28 × 10-8 s-1 is obtained at 300 ℃ and 70 MPa.At 50-70 MPa,with the increase of temperature rises from 250 ℃ to 300 ℃,the stress index changes from 2.30 to 3.22.At 250-300 ℃,with the increase of stress rises from 50 MPa to 70 MPa,the creep activation energy is changed from 65.4 k J/mol to 81.0 k J/mol.更多还原