Fracture Toughness and Fatigue Crack Propagation Determination of Metal Matrix Composite Materials
SourceMetal matrix composite materials comprised of hard carbide particles in various titanium alloy matrices have been developed which may be utilized for biomedical applications requiring high-wear-resistance materials (i.e., spinal disc replacement). Two matrix materials, an alpha-beta and a beta titanium, were evaluated with varying carbide contents ranging from 0 % to 15 % by volume. In general, the alpha-beta titanium matrix yielded higher fracture toughness and resistance to crack propagation compared to the beta matrix composites. This matrix also showed less sensitivity to wet testing conditions over the beta matrices, retaining its increased toughness with increased carbide content. The addition of carbide particles generally reduced the fracture and fatigue properties; however, the effect was variable. It was observed that, of the composite materials, the 10 % carbide in an alpha-beta titanium matrix composite yielded the highest fracture toughness (30.7 MPa·m1/2) and fatigue crack threshold (2.2 MPa·m1/2) and was the most stable with respect to environment.