In-Situ Laser Polishing Additive Manufactured AlSi10Mg: Effect of Laser Polishing Strategy on Surface Morphology, Roughness and Microhardness

Materials

Xin Zhou¹  Jiantao Zhou²  Dongqi Zhang²  Xu Han²  Hui Li²  Shengnan Shen²  Sheng Liu² 

[1] Science and Technology on Plasma Dynamics Laboratory, Air Force Engineering University, Changle East Road, Baqiao District, Xi’an 710038, China;The Institute of Technological Sciences, Wuhan University, South Donghu Road, Wuchang District, Wuhan 430072, China;

关键词: additive manufacturing;    laser polishing;    surface roughness;    microhardness;   

DOI  :  10.3390/ma14020393

来源: DOAJ

【 摘 要 】

Laser polishing is a widely used technology to improve the surface quality of the products. However, the investigation on the physical mechanism is still lacking. In this paper, the established numerical transient model reveals the rough surface evolution mechanism during laser polishing. Mass transfer driven by Marangoni force, surface tension and gravity appears in the laser-induced molten pool so that the polished surface topography tends to be smoother. The AlSi10Mg samples fabricated by laser-based powder bed fusion were polished at different laser hatching spaces, passes and directions to gain insight into the variation of the surface morphologies, roughness and microhardness in this paper. The experimental results show that after laser polishing, the surface roughness of Ra and Sa of the upper surface can be reduced from 12.5 μm to 3.7 μm and from to 29.3 μm to 8.4 μm, respectively, due to sufficient wetting in the molten pool. The microhardness of the upper surface can be elevated from 112.3 HV to 176.9 HV under the combined influence of the grain refinement, elements distribution change and surface defects elimination. Better surface quality can be gained by decreasing the hatching space, increasing polishing pass or choosing apposite laser direction.

【 授权许可】

Unknown