Weakest region analysis of non-combustible Mg products fabricated by selective laser melting. (October 2019)

• Record Type: Journal Article
• Authors: Proaño, Bryan; Miyahara, Hirofumi; Matsumoto, Toshiharu; Hamada, Shigeru; Sakai, Hitoshi; Ogawa, Kiyoshi; Suyalatu, ; Noguchi, Hiroshi
• Is Part Of: Theoretical and applied fracture mechanics. Volume 103(2019)
• Publication Date: 2019-10
• Subjects: Selective laser melting -- Mg alloy powder -- Weakest region -- Fracture toughness; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2019.102291
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: An Mg-9%Al-2%Ca alloy specimen was made by using a selective laser melting process. This tensile specimen consists of fine grain and coarse grain. The coarse grain leads to a stable crack propagation that originated from a defect. The effects must be considered in order to determine the fracture toughness. The results can improve the process stability for non-combustible magnesium products. Abstract: In this study, several Mg-9%Al-2%Ca alloy specimens were made using selective laser melting process (SLM) and subsequently subjected to tensile testing. Results showed that the microstructure of this specimen consist of fine grain, which serves to harden the material, and coarse grain, which is defined by the relatively slowly cooled region, softening the material and increasing its plasticity. The coarse grain tended to preferentially solidify immediately below the outer surface of the sample, which could lead to a stable crack propagation that originated from a defect located at the surface as a consequence of the intrinsic irregularity of SLM processes, the effects of which must be considered in order to determine the fracture toughness. Based on this information, corresponding measures can be provided in order to improve the process stability for non-combustible magnesium products.