钛合金中的β斑点及其研究方法

β-Fleck in Titanium and Its Investigation Method

采用板状试样研究了β斑点对Ｔｉ－１０Ｖ—２Ｆｅ—３Ａｌ合金低周疲劳性能的影响后发现，先将试样两个表面抛光、腐蚀，显示β斑点存在的部位：进而通过光学和电子金相，观察断裂试样两端断口的宏观和微观组织的──对应关系，可以清楚地渴示β斑区的电子扫描特征和断裂机制。从而能定性地分析性能与β斑点的关系；并能定量地统计β斑点含量ＰＡ（占断裂截面积的百分比）和最大β斑点面积Ｓｍａｘ对合金塑性和低周疲劳寿命的影响程度，从理论上阐明β斑点降低性能的原因。

he effect of β-fleck on fatigue property of Ti-10V-2Fe-3Al alloys is investigated. In the test, the two surfaces of plate-like fatigue sample are polished and etched to show β-flecks. In the corresponding position, macrostructure and microstructure of fracture samples are observed by SEM and optical micrograph and the SEM characteristics and fracture mechanism of β-fleck are clearly revealed. Then the correlation of β-fleck and properties can be qualitatively analysed, also the β-fleck volume fraction PA (ratio of statistic β-fleck area to cross-section area of fracture surface) ahd maximum p-fleck area S.and their effects on ductility and low- cycle fatigue life can be quantitatively measured,so that the reason of decreased properties caused by β-fleck is made clear.