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采用不同的等温锻造火次和相同的总变形量,改变TG6合金锻件的加热时间和每火次变形量,对该合金等温锻件的显微组织演化与拉伸性能进行研究。结果表明:随等温锻造火次增多,组织中初生α相含量增多,片状次生α相长度和亚β晶粒尺寸先减小后增大,而片状α相的厚度递增。室温和高温拉伸强度随锻造火次的增加呈现先减少后增加的趋势,塑性则先增加后减小。1火次成形时变形量较大,锻件产生温升造成组织中初生α相较少,同时较多且细长的次生α相增加了该锻件的拉伸强度。3火次成形时由于合金中各相再结晶程度不同,使组织中亚β晶界处产生较多细小等轴α相,该相增加了锻件的塑性。5火次锻造时,锻件加热时间较长,造成组织中α相的聚集长大。TG6合金等温锻造多火次成形时,每火次变形量存在一临界范围,处于该范围内每火次锻后空冷时合金发生部分再结晶,形成较为细小的等轴α相,阻碍亚β晶界的迁移,致使亚β晶粒尺寸较小,同时也造成组织中等轴α相尺寸的不均匀。
Different isothermal forging times and the same total deformation were used to change the heating time of TG6 alloy forging and the amount of deformation per fire. The microstructure evolution and tensile properties of isothermal forgings were studied. The results show that as the isothermal forging increases, the content of primary α phase increases, the length of secondary α phase and the size of sub-β decrease at first and then increase, while the thickness of α-phase increases. Tensile strength at room temperature and high temperature showed a trend of decreasing and then increasing with the increase of forging fire times, and plasticity firstly increased and then decreased. In the first heat deformation, the deformation is larger, the temperature rise of the forging produces less α in the microstructure, and more and elongated secondary α phase increases the tensile strength of the forging. During the forming process, the microstructure of the forgings is increased because of the different degree of recrystallization of each phase in the alloy during the forming process. 5 fire forging, forging a longer heating time, resulting in the organization of α-phase aggregation and growth. TG6 alloy isothermal forging multiple fire forming, the deformation per fire there is a critical range, within this range after each fire forged after air cooling part of the alloy recrystallization, the formation of smaller equiaxed alpha phase, blocking the sub-beta crystal Boundary migration, resulting in sub-β grain size smaller, but also cause the organization of the secondary axis α-phase size is not uniform.