In this work, the in-situ TiC panicles reinforced composite coating was prepared by plasma transferred arc process on the surface of Q235 steel. Microstructures, phase composition and wear property of the coating were...In this work, the in-situ TiC panicles reinforced composite coating was prepared by plasma transferred arc process on the surface of Q235 steel. Microstructures, phase composition and wear property of the coating were investigated. The results showed that the composite coating consisted mainly of T-Ni, TiC, Cr23C6, Cr7C3, Ni3Si, CrB, Cr5B3 and FeNi3 phases, and was characterized by fine TiC panicles embedded in Ni matrix. The wear resistance of composite coating was significantly improved compared with that of the steel substrate. The wear volume loss of the substrate was 443 mm3, which was about 9 times as that of in-situ TiC particles reinforced composite coating （49 mm3 ）. It is mainly attributed to the presence of chromium carbide particles and in-situ TiC particles and their favorable combination with Ni matrix.展开更多
The 6005A-T6 aluminum alloy was friction stir welded, and the peak temperature as well as microstructure was examined for the joints. A special attention was devoted to the precipitates evolution within different zone...The 6005A-T6 aluminum alloy was friction stir welded, and the peak temperature as well as microstructure was examined for the joints. A special attention was devoted to the precipitates evolution within different zones after post-weld natural aging time for 6 months. In the nugget zone （NZ） experiencing the highest peak temperature, the β′ precipitates dissolved into a-Al matrix and the GP zones re-precipitated after natural aging. In the thermo-mechanically affected zone （TMAZ）, which is characterized by a high density of dislocation, the Q＇ phases precipitated and part of them dissolved into α-Al matrix during FSW and the GP zones heterogeneously re-precipitated on dislocations after natural aging. The heat- affected zone （HAZ） contains the coarsening of β′ precipitates, the transformation of β″ to β′ and the precipitation of Q＇.展开更多
文摘In this work, the in-situ TiC panicles reinforced composite coating was prepared by plasma transferred arc process on the surface of Q235 steel. Microstructures, phase composition and wear property of the coating were investigated. The results showed that the composite coating consisted mainly of T-Ni, TiC, Cr23C6, Cr7C3, Ni3Si, CrB, Cr5B3 and FeNi3 phases, and was characterized by fine TiC panicles embedded in Ni matrix. The wear resistance of composite coating was significantly improved compared with that of the steel substrate. The wear volume loss of the substrate was 443 mm3, which was about 9 times as that of in-situ TiC particles reinforced composite coating （49 mm3 ）. It is mainly attributed to the presence of chromium carbide particles and in-situ TiC particles and their favorable combination with Ni matrix.
文摘The 6005A-T6 aluminum alloy was friction stir welded, and the peak temperature as well as microstructure was examined for the joints. A special attention was devoted to the precipitates evolution within different zones after post-weld natural aging time for 6 months. In the nugget zone （NZ） experiencing the highest peak temperature, the β′ precipitates dissolved into a-Al matrix and the GP zones re-precipitated after natural aging. In the thermo-mechanically affected zone （TMAZ）, which is characterized by a high density of dislocation, the Q＇ phases precipitated and part of them dissolved into α-Al matrix during FSW and the GP zones heterogeneously re-precipitated on dislocations after natural aging. The heat- affected zone （HAZ） contains the coarsening of β′ precipitates, the transformation of β″ to β′ and the precipitation of Q＇.
