Friction and wear behaviors of compacted graphite iron with different biomimetic units fabricated by laser cladding

Mimicking the biological characters on the cuticles of pangolin scales, biomimetic units were fabricated on the surfaces of compacted graphite cast iron (CGI) with different unit materials using laser cladding process. The influences of various unit materials including TiC, WC, B₄C and Al₂O₃ powders on the friction and wear behaviors of CGI were investigated. The wear resistance mechanism of biomimetic specimens was discussed. The results indicated that the wear resistance of biomimetic specimens cladding TiC was the best; the specimens cladding WC or B₄C were in the middle; and the specimens cladding Al₂O₃ was the worst. The sequence of friction coefficient values of biomimetic specimens cladding different ceramic powders from high to low was B₄C, TiC, WC and Al₂O₃. The wear mechanism of untreated specimen was mainly adhesion wear, abrasive wear as well as the oxidation wear, whereas the adhesive wear and abrasive wear was the main wear mechanism of the regions of substrate in biomimetic specimens and slight adhesion, abrasive wear and fatigue wear on the regions of biomimetic units.