Fine duplex Ti-48Al alloy with high strength produced by forging based on near-γ microstructure
Fine duplex Ti-48Al alloy with high strength produced by forging based on near-γ microstructure
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DOI：
10.1016/j.jallcom.2023.169058
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发表时间：
2023-01
影响因子：
6.2
通讯作者：
Mengjie Yan;Fang Yang;Hongtao Zhang;Gang Yang;Haifeng Zhang;Chenzeng Zhang;Miao Qi;Jingcen Zhang-Ji
中科院分区：
文献类型：
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作者：
Mengjie Yan;Fang Yang;Hongtao Zhang;Gang Yang;Haifeng Zhang;Chenzeng Zhang;Miao Qi;Jingcen Zhang-Ji
TiAl基合金是一种优良的高温结构材料，但热加工性能差一直是阻碍其发展的瓶颈。在本研究中，我们考虑到热加工和力学性能的Ti-48铝合金，通过微观组织调整。以真空烧结制备的Ti-48 Al粉末合金为原料，制备了由等轴晶组成的近γ组织。虽然成分简单，但该合金在75%变形量的锻造后获得了很高的机械性能。锻造温度控制在1300 °C，可使组织转变为由γ/α2片层团和γ等轴晶组成的复相组织。锻造态合金在室温下的极限抗拉强度为650 ± 17 MPa，屈服强度为644 ± 16 MPa。它在高温下仍然保持高强度，在500 °C时极限拉伸强度为684 ± 19 MPa，700 °C时为700 ± 19 MPa，900 °C时为320 ± 10 MPa。此外，该合金还具有良好的塑性，在900 °C发生动态再结晶，延伸率达到58.2%。
TiAl-based alloy is an excellent high-temperature structural material, but poor hot workability has been the bottleneck hindering its development. In this study, we take into account the hot workability and mechanical properties of Ti-48Al alloy through microstructure adjustment. Powder metallurgy Ti-48Al alloy prepared by vacuum sintering is used as the raw material, which has a near-γ microstructure composed of equiaxed grains. Although the composition is simple, the alloy achieves high mechanical properties after forging with 75 % deformation. Controlling the forging temperature to 1300 °C can make the microstructure transform into a duplex structure composed of γ/α2 lamellar colonies and γ equiaxed grains. As-forged alloy has an ultimate tensile strength of 650 ± 17 MPa and a yield strength of 644 ± 16 MPa at room temperature. It still maintains high strength at high temperature, with ultimate tensile strength of 684 ± 19 MPa at 500 °C, 700 ± 19 MPa at 700 °C, and 320 ± 10 MPa at 900 °C. In addition, the alloy has good ductility with elongation of 58.2% due to dynamic recrystallization at 900 °C.