Influence of matrix characteristics on tensile properties of in situ synthesized TiC/TA15 composite

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2012-09, Vol.553, p.59-66
• Main Authors: Qi, J.Q., Wang, H.W., Zou, C.M., Wei, Z.J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Crack initiation; Cross-disciplinary physics: materials science; rheology; Elasticity and anelasticity; Elasticity. Plasticity; Elongation; Exact sciences and technology; Fracture mechanics; Fractures; Heat treatment; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Other materials; Particulate composites; Physics; Specific materials; Tensile properties; TiC; Titanium carbide; Titanium matrix composites; Treatment of materials and its effects on microstructure and properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2012.05.092

► Heat treatment can enhance UTS markedly below 600°C. ► Increased UTS is accompanied by a rapid decrease in ductility at room temperature. ► The effect of matrix characteristic on UTS is very small at 650°C. ► Fine lamellar microstructure shows a good combination of high UTS and elongation. ► Particle fracture dominates the failure of the composite below 650°C. In the present paper, in situ synthesized 10vol.% TiC/TA15 composite has been fabricated by induction melting and common casting utilizing the reaction between titanium and C powder. Three types of heat treatment processes were performed on the as-cast composite and, accordingly, fine fully lamellar, bi-modal and near-equiaxed microstructures were obtained. The tensile properties were tested at room temperature, 600°C and 650°C. The results show that heat treatment can evidently enhance UTS below 600°C. The increased UTS is accompanied by the rapid decrease in tensile elongation at room temperature. As tensile temperature increases to 650°C, the discrepancy in UTSs of the composite with different matrix microstructures becomes small. The composite with fine fully lamellar microstructure exhibits a good combination of relatively high UTS and high tensile elongation in comparison with that with bi-modal and near-equiaxed microstructures. Below 650°C, the damage of the composite before and after heat treatment is mainly initiated by the fracture of TiC particles followed by the ductile failure of the matrix.