复合增强镍基合金火焰热喷焊层组织和性能的研究-材料科学与工程专业论文.docxVIP

安徽工业大学硕士学位论文摘要 安徽工业大学硕士学位论文 摘要 万方数据 万方数据 对镍基合金热喷焊层的耐腐蚀性试验结果表明，在相同试验条件下，原始热喷焊层 的耐腐蚀性最差，经激光重熔处理后其耐腐性得到一定程度的提高，之后经短时时效处 理后重熔热喷焊层的耐腐蚀性有所降低，然而经进一步长时时效处理后，重熔热喷焊层 的耐腐蚀性则表现为有一定程度的提高。 关键词：镍基合金；热喷焊层；激光重熔；时效处理；组织；性能 II - 安徽工业大学硕士学位论文ab 安徽工业大学硕士学位论文 abstract Study on Microstructure and Properties of Composite Strengthening Ni-based Alloy Flame Hot Sprayed-welding Layers Abstract Microstructure characteristic of Ni-based alloy hot sprayed layer and hot sprayed-welding layer are analysed, especially the microstructure changes and strengthening mechanisms of Ni- based alloy hot sprayed-welding layers with laser remelting and further aging treatment are mainly studied by means of optical microscope(OM), scanning electron microscopy(SEM), transmission electron micrograph(TEM) and X-ray diffraction(XRD). Moreover, microhardness, wear resistance, thermal shock resistance, high temperature oxidation resistance and corrosion resistance of hot sprayed-welding layers with different processings are also tested, compared and analyzed. The study on Ni-based alloy hot sprayed layer spraying on surface of Q345 steel shows a kind of mechanical binding with Q345 steel matrix, but the hot sprayed-welding layer shows a kind of metallurgical bonding with matrix. Also, hot sprayed-welding layer has a bigger thickness and there is a white band in the binding area. The study on Ni-based alloy hot sprayed-welding layer and laser remelted hot sprayed- welding layers show that microstructure of Ni-based hot sprayed-welding layer is coarse and at the same time there are some defects such as inclusion, pores and so on; After laser remelting, microstructure of Ni-based hot sprayed-welding layer is greatly refined, and defects in the hot sprayed-welding layer are nearly eliminated. The microstructure of remelted hot sprayed- welding layer mainly consists of fine dendrites with small lamellar eutectic structure in their branches and some compounds hard phase. And under the same process conditions, the lower o