光学精密工程2012，Vol.20Issue(11)：2402-2410,9.DOI:10.3788/OPE.20122011.2402
交变磁场对激光熔覆铁基复合涂层宏观形貌的影响及其微观组织演变
Influence of alternative magnetic field on macro morphology and microstructure of laser cladding Fe-based composite coating
摘要
Abstract
A alternative magnetic field generator is prepared by special circuits and active coils and the effects of different magnetic field intensities on the macro morphologies and microstructures of Fe-based composite coatings are studied by laser cladding process. Based on the electromagnetic principle and liquid metal solidification theory, it describes the solidification process of laser cladding coatings and reveals the main mechanism that magnetic field induced columnar dendrites transform into equi-axed crystals. The results show that the skin effect of liquid metal molten pool surface and alternating electromagnetic force allow the solidified cladding layer surface morphology to the wave form. The height of cladding layer and cross-section area decrease with the increase of magnetic field current, but the cladding layer width changes a little. The electromagnetic force in molten pool interior drives the dendrite ablation and mechanical break, and the free broken dendrites become a new nuclei to increase the nucleation rate, by which the top microstructure of cladding layer transforms from dendrite crys-tals to equiaxed crystals. Furthermore, the equiaxed crystal zone becomes wider with the increase of magnetic field current, but the bottom microstructure has a little change.关键词
激光熔覆/交变磁场/复合涂层/宏观形貌/显微组织Key words
laser cladding/ AC magnetic field/ composite coating/ macro morphology/ microstructure分类
矿业与冶金引用本文复制引用
刘洪喜,蔡川雄,蒋业华,张晓伟,王传琦..交变磁场对激光熔覆铁基复合涂层宏观形貌的影响及其微观组织演变[J].光学精密工程,2012,20(11):2402-2410,9.基金项目
国家自然科学基金资助项目(No.51165015) （No.51165015）
昆明理工大学分析测试基金资助项目(No.2011008) （No.2011008）
