航空发动机钛合金材料的高周和超高周疲劳性能研究

HIGH-CYCLE AND GIGA-CYCLE FATIGUE PROPERTIES OF TITANIUM ALLOY FOR AERO-ENGINE

  • 摘要: 通过对航空发动机空心风扇叶片用Ti-6Al-4V 随炉试样的高周和超高周疲劳试验研究,揭示了Ti-6Al-4V 材料在107 循环周次以上同样会发生疲劳破坏. 采用三参数幂函数寿命曲线拟合了高周和超高周的疲劳性能数据,发现可以较好地将两种试验下的数据衔接起来,结果显示在此试验条件下基于超声的超高周疲劳试验的频率效应可以忽略. 通过断口分析表明,超高周试样在试样表面没有缺陷的情况下,裂纹大多数是从材料内部或次表面萌生,而高周疲劳试样的裂纹是从材料表面开始萌生.

     

    Abstract: The high-cycle and giga-cycle fatigue properties of Ti-6Al-4V for hollow fan blade of aero-engine are investigated. The observations show that the Ti-6Al-4V may have fatigue failure above the 107 cycles. The high-cycle and giga-cycle fatigue data are fitted by three parameter power function life curves. The data obtained by two test methods can be joined smoothly. It is concluded that the effect of frequency on giga-cycle fatigue properties under the test conditions is negligible. The fractograph of specimens is analyzed, which indicates that the giga-cycle specimens might generate internal fractures or surface fractures while there are not defects on the specimen surface, and the high-cycle specimens generate only surface fractures.

     

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