Microstructure and mechanical properties of Ni-based composite coatings reinforced by in situ synthesized TiB2 + TiC by laser cladding
来源期刊：International Journal of Minerals Metallurgy and Materials2013年第1期
论文作者：Jun Li Xuan-jun Zhang Hui-ping Wang Man-ping Li
文章页码：57 - 64
摘 要：A Ni-based composite coating reinforced by in situ synthesized TiB2 and TiC particles was fabricated on Ti6Al4V by laser cladding. An attempt was made to correlate the thermodynamic predictions and experimental observation. The micro-structure and the microhardness profile across the coating were investigated by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and a hardness tester. It is found that the coating mainly consists of a large number of reinforcements （black blocky TiB2, flower-like or equiaxial TiC, and fine acicular CrB） and the γ matrix. The hardness of TiB2, TiC, and CrB reinforcements is much higher than that of the γ matrix. The dispersive distribution of such high hardness reinforcements causes the increase in hardness of the whole coating. The average value of the hardness is approximately Hv0.2 700 in the coating. The hardness of the coating is obviously higher than that of the substrate due to the dispersion strengthening of reinforcements.
Jun Li，Xuan-jun Zhang，Hui-ping Wang，Man-ping Li
School of Materials Engineering, Shanghai University of Engineering Science
摘 要：A Ni-based composite coating reinforced by in situ synthesized TiB2 and TiC particles was fabricated on Ti6Al4V by laser cladding. An attempt was made to correlate the thermodynamic predictions and experimental observation. The micro-structure and the microhardness profile across the coating were investigated by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, and a hardness tester. It is found that the coating mainly consists of a large number of reinforcements （black blocky TiB2, flower-like or equiaxial TiC, and fine acicular CrB） and the γ matrix. The hardness of TiB2, TiC, and CrB reinforcements is much higher than that of the γ matrix. The dispersive distribution of such high hardness reinforcements causes the increase in hardness of the whole coating. The average value of the hardness is approximately Hv0.2 700 in the coating. The hardness of the coating is obviously higher than that of the substrate due to the dispersion strengthening of reinforcements.
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