Dyer Ashley, Jones Jonathan, Cutts Richard, Whittaker Mark
Institute of Structural Materials, College of Engineering, Swansea University Bay Campus, Fabian Way, Skewen, Swansea SA1 8EN, UK.
Rolls-Royce plc, P.O. Box 31, Derby DE24 8BJ, UK.
Materials (Basel). 2019 Mar 22;12(6):953. doi: 10.3390/ma12060953.
The thermo-mechanical fatigue (TMF) behaviour of a Ti-6Al-4V matrix composite reinforced with SCS-6 silicon carbide fibres (140 μm longitudinal fibres, laid up hexagonally) has been investigated. In-phase and out-of-phase TMF cycles were utilized, cycling between 80⁻300 °C, with varying maximum stress. The microstructure and fracture surfaces were studied using electron backscatter diffraction (EBSD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), profilometry, and optical microscopy. The results have shown the damaging effect of out-of-phase cycling with crack initiation occurring earlier than in in-phase tests and crack propagation rates being accelerated in out-of-phase cycles. Fatigue crack initiation has been shown to be sensitive to crystallographic texture in the cladding material and thermo-mechanical fatigue test results can be considered according to a previously proposed conceptual framework for the interpretation of metal matrix composite fatigue.
研究了用SCS - 6碳化硅纤维（140μm纵向纤维，六边形铺设）增强的Ti-6Al-4V基复合材料的热机械疲劳（TMF）行为。采用同相和异相TMF循环，在80⁻300°C之间循环，最大应力不同。使用电子背散射衍射（EBSD）、能量色散X射线光谱（EDS）、扫描电子显微镜（SEM）、轮廓仪和光学显微镜研究了微观结构和断口表面。结果表明，异相循环具有损伤效应，裂纹萌生比同相试验更早发生，且裂纹扩展速率在异相循环中加快。已表明疲劳裂纹萌生对覆层材料中的晶体织构敏感，热机械疲劳试验结果可根据先前提出的用于解释金属基复合材料疲劳的概念框架来考虑。
