不同时效状态3J21合金拉伸性能

文摘在万能拉伸试验机上对大气环境下欠时效态、峰时效态和过时效态3 J21合金的拉伸性能进行研究,并采用金相显微镜、X射线衍射仪对各时效态金相组织及物相进行分析,采用TEM对固溶态、时效态试样及拉伸断口附近形变的显微组织进行分析,采用扫描电镜对拉伸断口进行观察。结果表明,峰时效态3 J21合金的拉伸强度和屈服强度均略高于欠时效态和过时效态合金,但其伸长率略低于欠时效态和过时效态合金;各时效态合金的拉伸断口均为韧窝断口,欠时效态合金断口附近显微组织中滑移线之间的距离最小,峰时效态合金滑移线之间的距离最大,而过时效态合金滑移线之间的距离介于两者之间。

Tensile Properties of 3J21 Alloy at Different Aged States

A study was conducted of the tensile properties of 3J21 alloy at under-aged,peak-aged and over-aged states on a universal tensile test machine at room temperature under atmospheric conditions.Moreover,a metallographic microscope and X-ray diffractometer were used to analyze the metallographic structure and physical phase of the alloy at various aged states.By employing a transmission electron microscope an analysis was conducted of the specimens of solid solution state and aged state as well as the microstructure of deformation near the tensile fracture.With the use of a scanning electron microscope a tensile fracture was observed.It is found that at roomtemperature and peak-aged state the strength of extension and yield strength of 3J21 alloy are slightly higher than those of the alloy at under-aged and over-aged states.However,its elongation rate is lower than that of the alloy at under-aged and over-aged states.The tensile fracture of the alloy at various aged state is,without exception,of the dimple fracture.The distance between the slip lines in the microstructure near the fracture of the alloy at under-aged state is the smallest,while that of the alloy at peak-aged state is the largest.The distance between the slip lines of the alloy at over-aged state assumes a value intermediate of the above two distances.