1992 Volume 10 Issue 4 Pages 515-519
In this study, the authors have investigated on fatigue properties of titanium-matrix composites reinforced with SiC (CVD) fiber (FRM). The fatigue properties were examined for as-fabricated FRM, thermal-exposed FRM and unreinforced commercial pure titanium(CPTi) and Ti-21V-4Al alloy matrix.
The fatigue strength of the as-fabricated FRM is three times higher than unreinforced CPTi and Ti-21V-4Al alloy. It is because the impeding effect of the fiber leads to low crack growth rates. After long thermal exposure (12h for CPTi FRM and 24h for Ti-21V-4Al FRM) at 1123 K, the FRM crack growth resistance is reduced mainly due to fiber degradation and notch effect of reaction zone. The fatigue properties of the Ti-21V-4Al FRM was lower than CPTi FRM because of coarsening of the grain of matrix. The fatigue properties of FRM is rarely determined as the deciding factor in that of matrix.