Effect of electric-magnetic compound field on the pore distribution in laser cladding process
Effect of electric-magnetic compound field on the pore distribution in laser cladding process
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DOI：
10.1016/j.optlastec.2018.06.037
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发表时间：
2018-12
影响因子：
5
通讯作者：
N. Zhang;Wei-Wei Liu-Wei;D. Deng;Zi-jue Tang;Xuyang Liu;Zhaorui Yan;Hong-chao Zhang
中科院分区：
文献类型：
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作者：
N. Zhang;Wei-Wei Liu-Wei;D. Deng;Zi-jue Tang;Xuyang Liu;Zhaorui Yan;Hong-chao Zhang
气孔缺陷和气孔分布不均匀分别是激光熔覆和激光熔凝多孔金属中的难题。因此，有必要开发一种通用的方法来实现不同制造工艺的孔隙合理分布。本文采用电磁复合场来改变熔池中气孔的应力状态，从而对气孔的溢流速度产生明显的影响。实验中采用含92%AISI 316L和8%TiH2的激光熔覆粉末，以获得稳定的气孔分布。实验结果表明，施加向下的安培力后，熔覆层的孔隙率和孔径均减小，孔隙分布向熔覆层表面集中。同时观察到孔隙率增加的趋势，并且当施加向上的安培力时，孔隙分布更均匀。当衬底电流为120 A时，孔隙率降低了64.71%，而当衬底电流为-90 A时，孔隙率增加了144%。阐述了不同安培力作用下熔覆层形状、显微组织和维氏硬度的变化。
The porosity defect and the inhomogeneous pore distribution are intractable problems in the conventional laser cladding process and the laser melting porous metal separately. Therefore, it is necessary to develop a common approach to achieve the rational distribution of pores for different manufacturing processes. In this paper, electric-magnetic compound field has been applied to change the stress state of pores in the molten pool which obviously influenced the overflow speed of pores. In experiments, the laser cladding powder containing 92% AISI 316L and 8% TiH2was adopted to obtain stable pore distribution. Results of experiments indicated that both the porosity and the pore size decreased and the pore distribution converged on the surface of the cladding layer when downward Ampere force was applied. Also an increasing tendency of porosity was observed and the pore distribution was more uniform when upward Ampere force was applied. The porosity decreased by 64.71% when the substrate current was 120 A while it increased by 144% when the substrate current was −90 A. The change of cladding shapes, microstructure and Vickers hardness of cladding layers under different Ampere force was also expounded.