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### Research Papers: Friction and Wear

J. Tribol. 2017;139(6):061601-061601-9. doi:10.1115/1.4035779.

The influence of load applied on wear depth of stir cast hybrid Gr/SiC/Al 6082 composites in a two-body abrasion was investigated in as cast (AC) and T6 heat-treated condition (T6). The obtained results were compared with its unreinforced alloy and SiC/Al 6082 composites. The parameters of the applied load (5–15 N), grit size (100 μm and 200 μm), and sliding distance of 75 m were used in this study. At 200-μm grit size, the wear depth of hybrid composites with respect to unreinforced matrix alloy was reduced by 38.1% (at 5 N load) and 16.2% (at 15 N load) in AC condition; 25.1% (at 5 N load), and 27% (at 15 N load) in T6 condition. The wear mechanisms were demonstrated through the analysis of wear surfaces.

Commentary by Dr. Valentin Fuster
J. Tribol. 2017;139(6):061602-061602-8. doi:10.1115/1.4035844.

In the present study, wear resistance composite cladding of Ni-based + 20% WC8Co (wt. %) was developed on SS-304 substrate using domestic microwave oven at 2.45 GHz and 900 W. The clad was developed within 300 s of microwave exposure using microwave hybrid heating (MHH) technique. The clad was characterized through scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Vicker’s microhardness, and dry sliding wear test. Microstructure study revealed that the clad of approximately 1.25 mm thickness was developed by partial mutual diffusion with substrate. It was observed that the developed clad was free from visible interfacial cracks with significantly less porosity (∼1.2%). XRD patterns of the clad confirmed the presence of Cr23C6, NiSi, and NiCr phases that eventually contributed to the enhancement in clad microhardness. Vicker’s microhardness of the processed clad surface was found to be 840 $±$ 20 HV, which was four times that of SS-304 substrate. In case of clad surface, wear mainly occurs due to debonding of carbide particles from the matrix, while plastic deformation and strong abrasion are responsible for the removal of material from SS-304 substrate.

Commentary by Dr. Valentin Fuster