Fabrication and characteristic evaluation of direct metal laser sintered SiC particulate reinforced Ti6Al4V metal matrix composites

摘要

The present work deals with the fabrication of silicon carbide (SiC) reinforced Ti6Al4V metal matrix composites (MMC's) by a direct metal laser sintering process, followed by characterization of microstructures and evaluation of mechanical properties. Variable process parameters like laser power density [3.528-5.172 W/cm(2) (x10(4))], SiC reinforcements (5%-15% by volume), and beam scanning speed (3500-4500 mm/min) and constant process parameters such as spot diameter (0.4 mm), hatching gap (0.2 mm), and layer thickness (0.4 mm) were considered to perform the experiments. The influence of addition of reinforcements on mechanical and physical properties of fabricated samples as compared to Ti6Al4V was examined. Field emission scanning electron microscope images show good metallurgical bonding between reinforcement and matrix. The presence of intermetallic compounds formed during the sintering process was detected by x-ray diffraction, which enhances the mechanical properties of the fabricated samples. Density of sintered samples increased on the increment in laser power density but decreased with an increase in the percentage of SiC in the mixture. Mean value of coefficient of friction was found in the range of 0.157-0.115 in a testing duration of 10 min, showing improvement in the wear resistance property as compared to Ti6Al4V. The improved mechanical properties and surface characteristics result in the formation of effective MMC's for various engineering applications.