Densification and crack suppression in selective laser melting of pure molybdenum
Densification and crack suppression in selective laser melting of pure molybdenum
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DOI：
10.1016/j.matdes.2017.04.094
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发表时间：
2017-09-05
影响因子：
8.4
通讯作者：
Shen, Zhijian
中科院分区：
文献类型：
--
作者：
Wang, Dianzheng;Yu, Chenfan;Shen, Zhijian
在这项研究中，致密和无裂纹的纯钼已被制造的选择性激光熔化。为了获得致密化，将前驱体粉末造粒并通过等离子体球化处理。由于球形粉末增加了激光吸收率和堆积密度，因此获得了10.16 g/cm（3）（理论密度的99.1%）的零件密度。利用电子背散射衍射分析了不同扫描策略下的裂纹扩展行为。激光逐层旋转扫描形成了互锁的晶界结构，增加了裂纹扩展阻力，导致裂纹偏离。通过应用设计的支撑结构，可以完全抑制裂缝。该研究为复杂钼零件的制备提供了一条新的途径。
In this study, dense and crack-free pure Mo has been fabricated by selective laser melting. In order to obtain densification, the precursor powders were granulated and processed by plasma spheroidization. Parts of density of 10.16 g/cm(3) (99.1% of theoretical density) were obtained with spherical powders because of its increased laser absorptivity and packing density. The crack growth behaviors under various scanning strategies are analyzed by electron backscattered diffraction. The interlocking grain boundary structure, which increased the crack growth resistance and caused crack deviation, is formed under layer-wise rotated laser scanning. Cracks can be fully suppressed by applying the designed supporting structure. This study provides a novel route for the fabrication of complex Mo parts.