Microstructural characterization of SiC reinforced Ti-6Al-4V metal matrix composites fabricated through powder metallurgy route

Titanium alloy specifically Ti-6Al-4V is largely used in aerospace industry owing to its high specific strength and stiffness. Further improvement in the specific strength and stiffness of the alloy can be achieved by reinforcing it with hard ceramic material like SiC. In the present investigation, different proportion of SiC particles (0, 1.5, 3 and 4.5 %) was introduced into the Ti-6Al-4V alloy to fabricate the metal matrix composite. The MMC's were prepared through powder metallurgy route which involves mechanical alloying of different powder in the predefined proportion followed by compaction and sintering in the furnace. The microstructure of fabricated composite was analyzed using scanning electron microscope. Uniform distribution of SiC particles in the titanium matrix is observed due to better wettability between the reinforcement and the matrix. The bulk hardness of the MMC's was measured on Rockwell Hardness (C scale). The x-ray diffraction analysis and EDX spectroscopy is also performed to capture the phase transformation after the sintering. The result shows that with the increase in the mass fraction of the SiC in the MMC's, a continuous increase in the hardness is observed. A 13.15 % increase in hardness is observed with 1.5 % addition of SiC in base Ti alloy. However, this percentage increase is increased to 26 % with addition of 4.5 % of SiC in the matrix. The increase in the hardness is due to higher hardness of reinforced SiC. SEM micrograph shows the uniform distribution of reinforced particle into the matrix.