(西北工业大学 材料科学与工程学院，西安 710072)
摘 要: 采用坯料加热温度超过β相变点而模具温度低于β相变点的热模锻造方式，利用光学显微镜和图像分析软件研究双重和三重热处理制度对TG6合金锻件显微组织的影响。结果表明：TG6合金热模锻件显微组织的不均匀性是由于变形时发生的β→α相变和微区变形的不均匀造成的。热处理制度不能彻底消除TG6合金锻件的显微组织不均匀性，但随高温保温时间的延长，不均匀程度降低。双重热处理时，第一重热处理后的冷却速率越慢，次生α相厚度越大。三重热处理时，第二重较高温度处理可显著地减小次生α相的尺寸。
关键字: TG6钛合金；热模锻造；组织不均匀性；热处理
TG6 alloy hot die forgings
（School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:TG6 alloy was forged by the hot die forging process in which the temperature of the billets was above the β transformation temperature and that of the die was below the β transformation temperature. The effects of double and triplex heat treatments on the microstructures of TG6 alloy forgings were studied by optical microscopy and image analysis software. The results show that the microstructure inhomogeneity is caused by the β→α transformation and the inhomogeneity of microdeforming. The microstructural inhomogeneity does not disappear absolutely after heat treatments, but with the increase of heating time, the inhomogeneity decreases. The thickness of secondary α phase becomes large with decrease of cooling rate after the first heat treatment during the double heat treatment. The second high temperature heat treatment decreases the size of secondary α phase during the triplex heat treatments.
Key words: TG6 titanium alloy; hot die forging; microstructural inhomogeneity; heat treatment
