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为获得环轧、胀形和热处理不同工艺组合状态下Ti-6Al-4V合金加工工艺-力学性能-微观组织之间的关系,分别对其α相和β相组织形貌,室温和高温拉伸性能(强度和塑性)进行观察与分析。研究表明,在适当的热处理工艺下,合金轧制成形之后增加第二工序胀形是很有必要的。材料的拉伸性能与初生α相的晶粒尺寸和体积分数,及次生α相的晶粒尺寸和组织厚度有很大关系。此外,胀形后热处理主要影响初生α相的晶粒尺寸及α相和β相组成比例,其次影响次生片状α相的大小和数量。当α相由小颗粒等轴组织转变为厚的多边形状组织时,材料的延伸率降低。随着初生α相体积分数的减少,未转变β相组织和弥散次生α相的增加,合金强度增加。材料高温拉伸断裂为韧性断裂,材料低塑性归因于组织断裂表面铸造微缺陷的萌生。
In order to obtain the relationship between the mechanical properties and the microstructure of the Ti-6Al-4V alloy during ring rolling, bulging and heat treatment, the effects of α phase and β phase morphology, room temperature and high temperature tensile Performance (strength and plasticity) for observation and analysis. Research shows that it is necessary to increase the second-step bulging after the alloy is rolled and formed under proper heat treatment process. Tensile properties of the material and the primary α-phase grain size and volume fraction, and secondary α-phase grain size and thickness of the tissue has a great relationship. In addition, the heat treatment after bulging affects mainly the grain size of the primary α phase and the proportion of the α phase and the β phase, and secondly, the size and amount of the secondary flaky α phase. When the α phase is transformed from a small particle equiaxed structure to a thick polygonal structure, the elongation of the material decreases. The strength of the alloy increased with the decrease of the volume fraction of the primary α phase, the increase of the β phase without transformation and the diffused secondary α phase. High temperature tensile fracture of the material is ductile fracture, and the low plasticity of the material is attributed to the initiation of micro-defects in the surface of the fracture surface of the tissue.