Texture and residual strain in two SiC/Ti-6-2-4-2 titanium composites

Residual strain and texture variations were measured in two titanium matrix composites reinforced with silicon carbide fibers (Ti/SiC) of similar composition but fabricated by different processing routes. Each composite comprised a Ti-6242 alpha/beta matrix alloy containing vol 35 pet continuous SiC fibers. In one, the matrix was produced by a plasma sprayed (PS) route, and in the other by a wire-drawn (WD) process. The PS and WD composites were reinforced with SCS-6 (SiC) and Trimarc (SiC) fibers, respectively. The texture in the titanium matrices differed significantly. The titanium matrix for the PS material exhibited random texture pre and post fabrication of the composite. For the WD material, the starting texture of the monolithic titanium matrix was approximate to 17 times random, but after consolidation into composite form, it was approximate to 6 times random. No significant differences were noted in the fiber-induced matrix residual strains between the composites prepared by the two procedures. However, the Trimarc (WD) fibers recorded higher (approximate to 1.3 times) compressive strains than the SCS-6 (PS) fibers. Stresses and stress balance results are reported. Plane-specific elastic moduli, measured in load tests on the unreinforced matrices, showed little difference.