Fracture and fatigue behaviour of a laser additive manufactured Zr-based bulk metallic glass

Viscous Flow of Supercooled Liquid in a Zr-Based Bulk Metallic Glass Synthesized by Additive Manufacturing

“…As pointed out by several works, the evolution of pores is inevitable during LPBF [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. It can arise during the powder deposition, from hollow powder particles and from the laser power distribution [ 8 ].…”

“…Aside from the microstructure, the mechanical properties of additively manufactured BMGs at room temperature have been and still are the focus of intense research. For example, the mechanical response of additively manufactured BMGs was investigated when subjected to uniaxial compressive loading [ 8 , 9 , 13 , 15 , 16 ] and bending [ 5 , 15 ]. Owing to residual porosity, which acts as a stress concentrator, BMGs fabricated via LPBF yield at lower stresses, show less plastic deformability, and have a lower fatigue threshold [ 15 ] than their amorphous counterparts prepared by conventional copper mold casting.…”

“…For example, the mechanical response of additively manufactured BMGs was investigated when subjected to uniaxial compressive loading [ 8 , 9 , 13 , 15 , 16 ] and bending [ 5 , 15 ]. Owing to residual porosity, which acts as a stress concentrator, BMGs fabricated via LPBF yield at lower stresses, show less plastic deformability, and have a lower fatigue threshold [ 15 ] than their amorphous counterparts prepared by conventional copper mold casting. During LPBF processing, Zr-based glass-forming alloys are enriched in oxygen so that the resulting BMGs show a distinctly lower fracture toughness than cast BMGs [ 5 , 15 , 16 ].…”

“…Owing to residual porosity, which acts as a stress concentrator, BMGs fabricated via LPBF yield at lower stresses, show less plastic deformability, and have a lower fatigue threshold [ 15 ] than their amorphous counterparts prepared by conventional copper mold casting. During LPBF processing, Zr-based glass-forming alloys are enriched in oxygen so that the resulting BMGs show a distinctly lower fracture toughness than cast BMGs [ 5 , 15 , 16 ]. By contrast, their wear and corrosion resistances are similar [ 8 , 17 ].…”

“…Compared to room-temperature properties of additively manufactured BMGs, little attention has been paid to their structure and resulting properties at elevated temperatures. Only the relaxation behavior was investigated recently for Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 [ 9 ] and Zr 59.3 Cu 28.8 Nb 1.5 Al 10.4 [ 15 ] LPBF BMGs. Owing to the high cooling rates effective during LPBF [ 6 ], the corresponding BMGs show a lower atomic packing density readily reflected in larger relaxation enthalpies [ 9 ].…”