Characterization of boron carbide particulate reinforced in situ copper surface composites synthesized using friction stir processing

• Published in: Materials characterization 2013-10, Vol.84, p.16-27
• Main Authors: SATHISKUMAR, R, MURUGAN, N, DINAHARAN, I, VIJAY, S. J
• Format: Article
• Language: English
• Subjects: ABRASIVES; Applied sciences; BORON CARBIDES; Contact of materials. Friction. Wear; COPPER; Cross-disciplinary physics: materials science; rheology; Dispersion hardening metals; DISPERSIONS; Exact sciences and technology; FRICTION; GRAIN SIZE; MATERIALS SCIENCE; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; MICROHARDNESS; OPTICAL MICROSCOPES; PARTICLES; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Powder metallurgy. Composite materials; Production techniques; SCANNING ELECTRON MICROSCOPY; Solidification; SURFACES; WEAR
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2013.07.001

Friction stir processing has evolved as a novel solid state technique to fabricate surface composites. The objective of this work is to apply the friction stir processing technique to fabricate boron carbide particulate reinforced copper surface composites and investigate the effect of B{sub 4}C particles and its volume fraction on microstructure and sliding wear behavior of the same. A groove was prepared on 6 mm thick copper plates and packed with B{sub 4}C particles. The dimensions of the groove was varied to result in five different volume fractions of B{sub 4}C particles (0, 6, 12, 18 and 24 vol.%). A single pass friction stir processing was done using a tool rotational speed of 1000 rpm, travel speed of 40 mm/min and an axial force of 10 kN. Metallurgical characterization of the Cu/B{sub 4}C surface composites was carried out using optical microscope and scanning electron microscope. The sliding wear behavior was evaluated using a pin-on-disk apparatus. Results indicated that the B{sub 4}C particles significantly influenced the area, dispersion, grain size, microhardness and sliding wear behavior of the Cu/B{sub 4}C surface composites. When the volume fraction of B{sub 4}C was increased, the wear mode changed from microcutting to abrasive wear and wear debris was found to be finer. Highlights: • Fabrication of Cu/B{sub 4}C surface composite by friction stir processing • Analyzing the effect of B{sub 4}C particles on the properties of Cu/B4C surface composite • Increased volume fraction of B{sub 4}C particles reduced the area of surface composite. • Increased volume fraction of B{sub 4}C particles enhanced the microhardness and wear rate. • B{sub 4}C particles altered the wear mode from microcutting to abrasive.