摘要
通过对不同缺口类型试样的SEM原位观察分析,研究了全层 TiAl基合金的断裂机理.结果表明,在整个断裂过程中:1) 几乎都是穿层断裂;2) 出现大量的微裂纹.全层 TiAl基合金裂纹的形成、扩展有沿层和穿层两种方式,断裂方式取决于拉伸轴与层片位向之间的相应关系,当拉伸轴和层片位向近似平行时,断裂行为是穿层断裂和沿晶断裂行为,断裂过程的驱动力是拉伸应力,缺口类型只影响裂纹的起裂,而对随后的断裂几乎没有影响.
The fracture mechanism of fully lamellar TiAl alloys is investigated by means of in-situ SEM observation on different pre-notched specimens.The results indicate that,during the whole fracture process,there are two characteristics:(1) they are almost translamellar fracture and (2) there are a lot of nucleation microcracks.The crack formation and propagation of fully lamellar TiAl is related to the interlamellar fracture and translamellar one.The fracture manner depends on the correlation of lamellar orientation in the grain,with the tensile axis.As the tensile axis is nearly parallel to the lamellae,it shows a translamellar and intergranular fracture,the driving force of fracture is tensile stress.The type of notch only affects the initiation of crack, without any effect on the fracture mechanism.
出处
《兰州理工大学学报》
CAS
北大核心
2005年第1期4-8,共5页
Journal of Lanzhou University of Technology
基金
国家自然科学基金(59871015)
