摘要:
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研究了TC21钛合金在5.5×10-4s-1恒应变速率、40%变形程度条件下,等温锻造温度变化对锻件组织和性能的影响。结果表明:TC21钛合金显微组织对温度变化敏感,在两相区锻造时,显微组织由初生α相和β转变组织组成,并且随着变形温度的提高,初生等轴α相的含量逐渐减少,晶粒尺寸增大;在相变点温度锻造时得到网篮组织;在相变点以上温度锻造时得到片状组织。室温拉伸强度和断裂韧性随锻造温度的升高呈现增加趋势,室温拉伸塑性明显降低。在965℃等温锻造时,显微组织为较细的片状组织,强度、塑性和断裂韧性达到较佳匹配,获得较好的综合力学性能。965℃为较佳等温锻造温度。
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The effect of isothermal forging temperature on microstructure and mechanical properties of TC21 alloy forgings was studied by isothermal forging at the strain rate of 5.5×10-4s-1,deformation of 40%.The results show that the microstructure of TC21 is sensitive to forging temperature.The microstructure consists of primary α and transition β phase and when the alloy is deformed in α+β field,the volume fraction of primary equiaxed α decreases and its size increases with elevating temperature.Typical basketweave microstructure will be obtained when forging is made at the transition temperature,and the lamellar microstructure will be obtained in the β field.The tensile strength and fracture toughness are enhanced with elevating temperature,but the tensile ductility is reduced.When forging is made at 965℃,the thinner lamellar microstructure will be obtained,which possesses a good match among strength,plasticity and fracture toughness.965℃ is recommended for isothermal forging.
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参考文献:
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