Role of Er on the densification, microstructure and mechanical properties of 7075 aluminium alloys manufactured by laser powder bed fusion
Role of Er on the densification, microstructure and mechanical properties of 7075 aluminium alloys manufactured by laser powder bed fusion
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DOI：
10.1016/j.jmrt.2022.08.004
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
Min Li;Sen Yao;Jiajian Wang;Z. Chen;Guifeng Zhang;Shuzhe Zhang;Y. Li
中科院分区：
文献类型：
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作者：
Min Li;Sen Yao;Jiajian Wang;Z. Chen;Guifeng Zhang;Shuzhe Zhang;Y. Li
激光粉末床熔凝制备无裂纹7075铝合金是目前的研究热点。本文制备了7075Al + Er预合金粉末，通过调整工艺参数，采用激光束脉冲聚焦技术（LPBF）打印出了无裂纹的样品。讨论了工艺参数的影响及Er的抑裂机理。Er能生成与Al基体共格的Al3Er，具有晶粒细化作用，使柱状晶长度从106 μm缩短到84 μm，有利于浆料凝固阶段液膜的分散和进一步凝固。Al3Er还降低了织构强度，使热应力更均匀。最终测得的打印样品的拉伸强度为338 MPa，伸长率为15.9%，分别比未添加Er的7075 Al样品高32%和74.7%。本文探讨了稀土元素Er对激光粉末床熔凝7075铝合金印刷适性改善和裂纹抑制的影响，为高强度铝合金的无裂纹增材制造和应用提供实验支持。
Fabricating crack-free 7075 aluminium alloy by laser powder bed fusion (LPBF) is currently a hot research topic. In this work, pre-alloyed 7075Al + Er powder was prepared, and crack-free samples were printed by LPBF by adjusting the process parameters. Furthermore, the influence of process parameters and the mechanism of crack inhibition by Er were discussed. Er can generate Al3Er coherent with the Al matrix, which has the grain refinement effect, shortens the length of columnar crystals from 106 μm to 84 μm and is conducive to the dispersion and further solidification of the liquid film in the paste solidification stage. Al3Er also reduces the texture strength and makes the thermal stress more uniform. The final measured tensile strength of the printed sample was 338 MPa, and the elongation was 15.9%, which was 32% and 74.7% higher than those of the 7075Al samples without Er addition, respectively. In this work, the effect of rare earth element Er on the improvement of the printability and crack suppression of 7075 aluminium alloy by laser powder bed fusion was discussed, which provides experimental support for crack-free additive manufacturing and application of high-strength aluminium alloys.