Additive manufacturing of Ti-6Al-4V alloy by micro-laser metal wire deposition with pulsed wave emission: processability and microstructure formation

卷:126

Article

关键词: MECHANICAL-PROPERTIES;    GRAIN-REFINEMENT;    TITANIUM-ALLOYS;    FLUID-FLOW;    COMPONENTS;    FABRICATION;    TRANSITION;    MORPHOLOGY;    ALUMINUM;    POROSITY;   

DOI  :  10.1007/s00170-023-11238-y

来源: SCIE

【 摘 要 】

In this work, the micro-laser metal wire deposition (mu LMWD) with ms-pulsed wave emission and low duty cycles was utilized to build the Ti-6Al-4V thin walls. The work first investigated the influence of the process parameters on single track stability and geometry. With the developed processing conditions thin walls with multiple layers were produced. The mu LMWD produced thin walls were characterized by fine grain size expected to be due to the columnar to equiaxed transition (CET) in the produced wall. Fine columnar grains formed in the bottom region of wall due to the restriction of melt pool size and large cooling speed, while equiaxed grain formation and further refinement were achieved in the middle region, attributed to the intermittent stirring force that broke dendritic arms and increased nucleation events before solid-liquid interface. From the bottom to top region microstructures transferred from acicular alpha ' to short alpha lamella constituting basketweave structure, and the periodic heating and cooling generating by pulsed laser reduced the acicular alpha ' at higher cooling rate and decreased alpha size. The forming of equiaxed grain and fine grain and microstructure increased the wall microhardness.

【 授权许可】

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