某钛合金零件疲劳断裂影响因素分析
来源期刊：有色金属科学与工程2010年第1期
论文作者：肖国华 秦鹏高 李云周
文章页码：38 - 42
关键词：失效分析；断裂；疲劳；金相组织；硬度
Key words：failure analysis; fracture; fatigue; metallographic organization; hardness
摘 要：对振动疲劳试验后的一批某钛合金零件进行了荧光、表面加工质量、前后缘部位细根圆角检查．通过进一步的显微组织检查，显微硬度测定，以及裂纹断口的宏观形貌观察和部分断口的微观形貌观察发现，在应力给定的情况下，影响该批零件低寿命的主要因素是显微组织和细根圆角程度；提高金相组织等级可明显提高零件的疲劳性能，零件前缘R＜60μm的细根将明显降低零件的疲劳性能；硬度以(HVB0.2B)＞370为宜；加工痕迹的方向分布对寿命的影响比较小，其主要影响裂纹萌生的位置．
Abstract:
This paper tests the fatigue properties of a large-scaled titanium alloy parts, the fluorescent surface quality and fine roots rounded edge position. The most factor for the short performance time is microstructure and fine root fillet by further microstructure examination, micro-hardness determination and fracture surface morphology of macroscopic and microscopic observation and part of the fracture morphology observation under the given stress. The increase of metallographic structure levels obviously improves the fatigue performance. The frontal of the alloy part of the R＜60μm fine roots will decrease the fatigue property. It is suggested that the hardness larger than 370.(HVB0.2B＞370). The direction distribution of process trace has little effect on the service life of the spare parts.
