Effects of Al2O3 mass fraction on microstructure and friction-wear performance of laser cladded Fe90 alloy coating

Purpose This paper aims to improve the friction reduction and wear resistance of Fe90 alloy coating by the addition of Al2O3. Design/methodology/approach Fe90 alloy coatings with the different Al2O3 mass fractions were prepared on Q235 steel by laser cladding (LC). The morphologies, phases and hardness of Fe90 alloy coating were analyzed using a scanning electron microscope (SEM), X-ray diffraction (XRD) and microhardness tester, respectively. The effects of Al2O3 mass fraction on the coefficient of friction (COF) and wear rates of Fe90 alloy coating were investigated using a friction tester, and the wear model was built to discuss the wear mechanism of Al2O3-reinforced Fe90 alloy coating. Findings The results show that the large number of Fe carbides is generated on the Fe90-Al2O3 coatings by the effect of laser high energy, and the hardness of Fe90-coating is 806 HV0.5, which is 4.48 times of substrate. The average COFs of Fe90-Al2O3 alloy coatings decrease from 0.73 to 0.55, and the wear rates are also reduced from 447.78 to 274.63 mu m3 center dot s-1 center dot N-1 by the addition of Al2O3. The Fe90-6% Al2O3 coating presents the highest wear resistance among the three kinds of coatings, and the wear mechanism is abrasive wear and micro-cutting wear. Originality/value The Al2O3-reinforced Fe90 alloy coating was first fabricated by laser cladding, and the effect of Al2O3 on the friction-wear performance of Fe90 alloy coating was investigated.