In-situ manipulating microstructure of CoCrMo alloy using selective laser melting with a novel scanning strategy. (15th March 2022)

• Record Type: Journal Article
• Authors: Li, H.Q.; Shen, F.L.; Guo, H.; Zong, R.; Fang, X.Y.; Zhang, L.J.
• Is Part Of: Scripta materialia. Number 210(2022)
• Publication Date: 2022-03-15
• Subjects: Selective laser melting -- CoCrMo alloy -- Microstructure manipulation -- Mechanical properties; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.114468
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Three types of distinct dense microstructure, namely narrow columnar grains, nearly equiaxed refined grains, and duplex ε + γ microstructure, can be in-situ fabricated using a novel laser scanning strategy. The strategy includes a melting scanning with the laser energy density of 2∼26 J/mm 3 to refine the microstructure and multiple non-melting scanning with an extremely low laser energy density of 0.9∼1.8 J/mm 3 to produce a large amount of ε-martensite in the γ austenite matrix. As a result, an exceptionally high tensile strength of 1, 503 MPa, outstanding ductility of 18%, and improved hardness of 502 HV can be achieved through additional scanning with appropriate energy density. This work demonstrates that the microstructure of selected laser melted alloy can be in-situ manipulated to tune mechanical properties. Graphical abstract: Image, graphical abstract