Amorphous solid

Indentation hardness

Metallurgy

Materials science

Coating

Abrasive

Substrate (aquarium)

Geology

Oceanography

Amorphous metal

Organic chemistry

Cladding (metalworking)

Alloy

Microstructure

Composite material

Tribology

Chemistry

Tribology International

Co-based metallic glasses with ultrahigh strength and high microhardness are regarded as ideal surface-coating materials to significantly improve hardness and wear resistance of substrate materials. In this paper, a Co-based amorphous powder with high glass-forming ability was prepared by gas-atomization technique. Then a large-area Co-based amorphous coating was fabricated from the powder by laser cladding technology. The effects of different laser parameters (i.e., laser scanning speed and operating voltage) on glass formation of the amorphous coating were investigated. Furthermore, the thermal properties, microhardness and wear resistance of the amorphous coating produced with an optimal laser parameter were evaluated. The results indicate that the Co-based amorphous cladding layer exhibits extremely high microhardness of ~14.9 GPa, which can significantly improve the wear resistance of the substrate. A complex wear-failure mechanism of the Co-based coating is clarified as a mixture role of abrasive- & fatigue-wear, oxidation wear and adhesive wear proofed by microstructural and element-distribution analysis of various worn surface.

Tribological behaviors of high-hardness Co-based amorphous coatings fabricated by laser cladding