The Effect of SiC Addition on Microstructure and Mechanical Properties of Gas Tungsten Arc-Welded Ti-6Al-4V Alloy

In the present study, SiC powder was added in situ for bead-on-plate weldments and fusion butt joints to modify the microstructure and the corresponding mechanical properties. Cross sections of bead-on-plate welds demonstrated that the SiC addition resulted in significant changes of the titanium microstructure. Specifically, a fine lamellar structure of α-phase with a small amount of intergranular β-titanium within the fusion zone could be established. Moreover, the size of prior β-grains was significantly reduced. After welding, no intermetallic silicides were observed. In the fusion zone of the SiC-enhanced samples, a small increase in hardness resulted, and the samples showed an increase in tensile strength, yield strength and elongation.