Papers by Author: Xiang Liu

Abstract: Al-2%Mn alloy matrix composites reinforced with Al2O3 particulates was fabricated by stirring cast, and the composites was characterized and analyzed by using a variety of analytical techniques, such as XRD, SEM, EDS, Brinell hardness tester, ring-on-block tribometer, and erosion-corrosion tester. The results show that the composites in as cast condition is mainly composed of Al,  -Al2O3, MnAl6 and Al11Mn4 phase, and the Al2O3 particles are dispersed uniformly in the Al matrix. Compared with the base aluminium and the Al-2%Mn alloy, the HB hardness of the composites is increased significantly, and the wear loss is far less under the SO4•Cl- Na•Ca• Mg corrosive alkalescent aqueous solution lubricated condition. The erosive-corrosive wear rates of the composites are lower than those of the Al-2%Mn alloy irrespective of the rotational speed or the size of grinding particles. The Al2O3 particulates reinforced Al-2%Mn alloy matrix composites possesses a good wear-resistance and erosion-corrosion resistance due to its higher hardness.

Abstract: Fine martensite could be gained in 70Mn2Mo cast steel roller after solidification by laser treatment. The hardness and depth of hardened zone reached 920 HV (about 65HRC) and 0.6mm respectively. After tempered in high temperature, the depth of hardened zone whose hardness was maintained above 430HV was 0.4mm. These results showed the better anti-tempering property and the higher hardness and hardened depth compared with water quenching and implied the greater applied potentiality of laser strengthening.