Fatigue Properties of Tungsten Fiber Reinforced Ti-6Al-4Valloy by HIP Fabrication

Fatigue properties of tungsten fiber reinforced Ti-6Al-4V (W/Ti-6Al-4V) alloy has been investigated. W/Ti-6Al-4V composites were fabricated by 2 kinds of Hot Isostatic Pressing (HIP) conditions and elongated by 2 kinds of the following process by rotary swaging (RS), die forging (DF). The fatigue properties of these MMCs (metal matrix composites) were compaired with conventional Ti-6Al-4V alloy and HIP treated Ti-6Al-4V one. According to the results in the present study, the average hardness and fatigue strength of HIP-DF-0 showed higher values in comparison with those of conventional Ti-6Al-4V by about 20-30% and 15% respectively. However, the fatigue limit of MMCs was unexpectedly deteriorated in comparison to the conventional ones. The deterioration of the fatigue limit was considered to be due to the defects in the microstructure of the composites such as clustering of fibers, fiber orientation, micro-cracks and porosity.