Microstructure and mechanical properties of Zr-modified aluminum alloy 5083 manufactured by laser powder bed fusion

Effects of Alloy Composition and Solid-State Diffusion Kinetics on Powder Bed Fusion Cracking Susceptibility

“…Zr could be built to nearly full density without cracks and negligible Mg loss. However, in the study by Zhou et al, [5] even with Zr modification, cracking was still observed with faster-than-optimum scan speed, presumably due to changes in cooling rate and the effect of diffusion.…”

“…7as a function of (a) cell size, and (b) cooling rate determined for LPBF AlSi10Mg alloys [28] 5 Cracking Susceptibility of AA5083 Alloy AA5083 with 4.0 * 5.0 wt.% Mg, 0.4 * 1.0 wt.% Mn [27] is widely used in marine applications, and is known to be both castable and weldable. [27] However, investigators Zhou et al [5] clearly demonstrated that processing of corrosion resistant AA5083 by LPBF resulted in solidification cracking, regardless the LPBF parameter employed.…”

“…In the study by Zhou et al, [5] the cracking density and composition of alloying elements were measured as a function of varying scan speed for high and low laser powers of 350 and 200 W, respectively. The crack density measured was plotted against the concentration of Mg in Fig.…”

“…To mitigate the solidification cracking, Zhou et al [5] added 0.7 wt.% Zr to the AA5083, so that the primary Al 3 Zr precipitates can act as heterogenous nucleation sites and eliminate large columnar grains associated with solidification cracking. This change in solidification path allowed for an identification of optimum LPBF parameters, in which AA5083 ?…”

“…[1][2][3] Unfortunately, LPBF of certain Al-alloys such as high strength AA7075 and corrosion resistant AA5083 is limited by the extensive formation of solidification cracking and/or excessive porosity. [4][5][6][7] Predominantly, Al alloyed with near eutectic compositions of Si, * 12.6 wt.%, [8] such as Al-10 wt.% Si-0.5 wt.% Mg (known as AlSi10Mg), have had success with building crack-free parts with LPBF. [9][10][11] AlSi10Mg was adopted from casting as the high concentration of Si decreases the viscosity of the melt, allowing for a higher degree of flowability, desired in casting.…”