Characterization of gradient Ni-Fe/SiC composite coating on mild steel by thermal spraying in combination with laser cladding  

作　　者：Hu Mulin Pan Lin Fu Yongqing Xie Changsheng Wang Aihua 

机构地区：[1]State Key Laboratory of Die ＆ Mould Technology, Faculty of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430010, P. R. China [2]Wuhan Research Institute of Materials Protection, Wuhan 430030, P. R. China [3]Department of Engineering, University of Cambridge, CambridgeCB2 1TN, UK

出　　处：《材料保护》2005年第11期1-5,共5页Materials Protection

摘　　要：Metal matrix composite coating Ni-Fe/SiC was prepared on an iron-based substrate bythermal spraying combined with laser cladding,using SiC particulates as the reinforcing agent.The micro-structures of the coatings formed at different thermal spraying and laser cladding conditions were character-ized by means of X-ray diffraction and electron probe microanalysis.The thermal oxidation properties of themixed powders composed of different content of SiC particulates and relevant Ni-based alloy as the balancewere examined using differential scanning calorimetry.The hardness profile of the thermal sprayed and lasercladding coatings was investigated as well.It was found that SiO2particulates were generated and dissolvedand dispersed during the melting and solidification of the laser cladding process,which was ascribed to theoxidation of the dispersed SiC particulates.The micro-hardness depth profile of the target laser claddingcomposite coating was characterized by gradient distribution,which could be related to the gradient distribu-tion of the hard SiC and SiO2particulates in the dendrites and interdendrites of the cladding layer.Both SiCand SiO2particulates contributed to greatly increasing the microhardness and mechanical properties of the ti-tled laser cladding composite coatings.Metal matrix composite coating Ni-Fe/SiC was prepared on an iron -based substrate by thermal spraying combined with laser cladding, using SiC particulates as the reinforcing agent. The microstructures of the coatings formed at different thermal spraying and laser cladding conditions were characterized by means of X-ray diffraction and electron probe microanalysis. The thermal oxidation properties of the mixed powders composed of different content of SiC particulates and relevant Ni-based alloy as the balance were examined using differential scanning calorimetry. The hardness profile of the thermal sprayed and laser cladding coatings was investigated as well. It was found that SiO2 particulates were generated and dissolved and dispersed during the melting and solidification of the laser cladding process, which was ascribed to the oxidation of the dispersed SiC particulates. The micro - hardness depth profile of the target laser cladding composite coating was characterized by gradient distribution, which could be related to the gradient distribution of the hard SiC and SiO2 particulates in the dendrites and interdendrites of the cladding layer. Both SiC and SiO2 particulates contributed to greatly increasing the microhardness and mechanical properties of the titled laser cladding composite coatings.

关 键 词：复合材料 结构表征 涂层 热喷射 钢 金属表面防护 

分 类 号：TG174.444[金属学及工艺—金属表面处理]