TC1合金板材的“黑斑”组织研究

Study on"Black Fleck"Microstructure of TC1 Alloy Sheet

采用光学显微镜、SEM-EDS及EBSD等多种表征手段对TC1合金热轧过程中显微组织出现的异常“黑斑”组织进行研究,并将其与正常基体的力学性能进行对比。结果表明,异常“黑斑”组织区域内不存在成分偏析现象,其维氏硬度高于正常基体约23HV。“黑斑”组织的本质为细小的未再结晶的小角度晶界的亚晶晶粒,形成于轧制变形过程。提高热处理温度和延长保温时间对其形态等无明显影响,其室温和400℃高温拉伸力学性能和正常组织板材无明显差异。

The optical microscopy,SEM-EDS,EBSD and other detection and characterization methods were used to characterize and analyze the abnormal"black fleck"microstructure during the hot rolling process of TC1 alloy sheet.Moreover,the mechanical properties of the"black fleck"microstructure and normal matrix were also compared.The results show that there is no segregation phenomenon in these areas,whose average Vickers hardness is 23 HV higher than that of the normal matrix area.The essence of the"black fleck"microstructure is the fine non-recrystallized sub-crystalline grains with small angle grain boundaries,they are formed in the rolling deformation process.Increasing heat treatment temperature and extending holding time have no significant effects on the abnormal"black fleck"microstructure.In addition,there is no significant difference between the mechanical properties of abnormal"black fleck"microstruture and normal matrix microstruture at room temperature and 400℃.