Microstructure and wear behaviour of laser-induced thermite reaction Al₂O₃ ceramic coatings on pure aluminum and AA7075 aluminum alloy

Abstract

Wear-resistant laser-induced thermite reaction Al₂O₃ ceramic coatings can be fabricated on pure Al and AA7075 aluminum alloy by laser cladding (one-step method) and laser cladding followed by laser re-melting (two-step method) using mixed powders CuO-Al-SiO₂ in order to improve the wear properties of aluminum and aluminum alloy, respectively. The microstructure of the coatings was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The wear resistance of the coatings was evaluated under dry sliding wear test condition at room temperature. Owing to the presence of hard α-Al₂O₃ and γ-Al₂O₃ phases, the coatings exhibited excellent wear resistance. In addition, the wear resistance of the coatings fabricated by two-step method is superior to that of the coatings fabricated by one-step method.

Keywords

laser cladding / thermite reaction / aluminum alloy / wear

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