Materials Research Express (Jan 2020)

Sliding wear behavior of AZ91/B4C surface composites produced by friction stir processing

  • Hemendra Patle,
  • B Ratna Sunil,
  • Ravikumar Dumpala

DOI
https://doi.org/10.1088/2053-1591/ab6a55
Journal volume & issue
Vol. 7, no. 1
p. 016586

Abstract

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In the present study, the surface of AZ91 Mg alloy was modified by incorporating boron carbide (B _4 C) particles using friction stir processing (FSP). Sliding wear behavior of these developed AZ91/B _4 C surface composites was investigated against AISI 52100 steel ball using linear reciprocating tribometer. Hardness tests reveal that the hardness of the fabricated surface composite (∼137.47 HV) is significantly increased compared to the base metal (∼95.5 HV) due to the presence of B _4 C particles. Wear tests were conducted on the samples at two different sliding velocities; 0.06 m s ^−1 and 0.12 m s ^−1 . It was observed that at higher sliding velocity of 0.12 m s ^−1 , AZ91/B _4 C surface composite exhibited lower friction coefficient value in comparison to that of the base metal, whereas it is vice versa at the low sliding velocity of 0.06 m s ^−1 . However, surface composites exhibited superior wear resistance at both the sliding velocities, in comparison to that of the base metal. Scanning electron microscopy and energy-dispersive spectroscopy analysis of the wear tracks were carried out to understand the wear mechanisms. From the observations, a combination of abrasive, adhesive, and oxidative wear mechanisms were found to be prominent.

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