The origin of high-density dislocations in additively manufactured metals

By Ge Wang, Heng Ouyang, Chen Fan, Q. Guo, Zhiqiang Li, Wentao Yan, Zan Li. 2020

334 citations recorded by the source corpus.

ABSTRACT The origin of dense dislocations in many additively manufactured metals remains a mystery. We here employed pure Cu as a prototype and fabricated the very challenging high-purity (>99.9%) bulk Cu by laser powder-bed-fusion (L-PBF) technique. We found that high-density dislocations were present in the as-built samples and these high-density dislocations were introduced on the fly during the L-PBF process. A newly developed multi-physics modeling was further employed to interpret the origin of these pre-existing dislocations, demonstrating that the compression-tension cycles rendered by the localized heating/cooling heterogeneity upon laser scanning are responsible for the residual high-density dislocations. GRAPHICAL ABSTRACT IMPACT STATEMENT The origin of dense dislocation structures in many as-built additively manufactured metals, which incurs a long-standing dispute, was found to be inherent to the additive manufacturing process.

Subfields: Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/8f0412f1d8ec4ce4675bde805a467b364a680055