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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/cm2 (×104)], 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. [ABSTRACT FROM AUTHOR]

The growing need for high wear-resistant surface with enhanced physical properties has led to extensive researches in the field of surface engineering. Laser cladding emerged to be a promising method to achieve these objectives in a cost-effective way. The present paper studies the viability of cladding of tungsten disulfide (WS) powder by using 400 W continuous-wave fiber laser. WS was used as a coating material, which was decomposed at higher temperature and underwent several chemical reactions. By this process, in situ formation of metal matrix composites and hard face coating on the substrate surface were attained. The characterization of laser cladded surface was done to study its morphological, microstructural, mechanical and tribological properties. It was observed that cladding of WS powder on 304 SS resulted in the formation of Cr-W-C-Fe metal matrix composite having improved mechanical and tribological properties. The value of microhardness of the coated surface was found to increase three to four times in comparison with the parent material surface. Wear test results indicated a decrease in wear by 1/9th (maximum) as compared to the parent 304 SS surface. The volume fractions of tungsten particles on the cladded surface were also investigated through EDS analysis. [ABSTRACT FROM AUTHOR]