High-strength and thermally stable TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy fabricated via selective laser melting

To increase the processability and plasticity of the selective laser melting(SLM)fabricated Al-Mn-Mg-Er-Zr alloys,a novel TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy with a mixture of Al-Mn-Mg-Er-Zr and nano-TiB_(2) powders was fabricated by SLM.The pro-cessability,microstructure,and mechanical properties of the alloy were systematically investigated by density measurement,microstruc-ture characterization,and mechanical properties testing.The alloys fabricated at 250 W displayed higher relative densities due to a uni-formly smooth top surface and appropriate laser energy input.The maximum relative density value of the alloy reached(99.7±0.1)%,demonstrating good processability.The alloy exhibited a duplex grain microstructure consisting of columnar regions primarily and equiaxed regions with TiB_(2),Al6Mn,and Al3Er phases distributed along the grain boundaries.After directly aging treatment at a high tem-perature of 400℃,the strength of the SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy increased due to the precipitation of the secondary Al6Mn phases.The maximum yield strength and ultimate tensile strength of the aging alloy were measured to be(374±1)and(512±13)MPa,respectively.The SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy demonstrates exceptional strength and thermal stability due to the synergistic effects of the inhibition of grain growth,the incorporation of TiB_(2) nanoparticles,and the precipitation of secondary Al6Mn nanoparticles.

Influence of process parameters and aging treatment on the microstructure and mechanical properties of Al Si8Mg3 alloy fabricated by selective laser melting

Many studies have investigated the selective laser melting(SLM)of AlSi10Mg and AlSi7Mg alloys,but there are still lack of researches focused on Al-Si-Mg alloys specifically tailored for SLM.In this work,a novel high Mg-content AlSi8Mg3 alloy was specifically designed for SLM.The results showed that this new alloy exhibited excellent SLM processability with a lowest porosity of 0.07%.Massive lattice distortion led to a high Vickers hardness in samples fabricated at a high laser power due to the precipitation of Mg_(2)Si nanoparticles from theα-Al matrix induced by high-intensity intrinsic heat treatment during SLM.The maximum microhardness and compressive yield strength of the alloy reached HV(211±4)and(526±12)MPa,respectively.After aging treatment at 150℃,the maximum microhardness and compressive yield strength of the samples were further improved to HV(221±4)and(577±5)MPa,respectively.These values are higher than those of most known aluminum alloys fabricated by SLM.This paper provides a new idea for optimizing the mechanical properties of Al-Si-Mg alloys fabricated using SLM.

Erratum to:Influence of process parameters and aging treatment on the microstructure and mechanical properties of AlSi8Mg3 alloy fabricated by selective laser melting

Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 29, Number 9, September 2022, Page 1770https://doi.org/10.1007/s12613-021-2287-1The original version of this article unfortunately contained a mistake due to the PDF file conversion through different softwares. The presentation of Fig. 13 in original version was incorrect.

Strengthening mechanisms of high-performance Al-Mn-Mg-Sc-Zr alloy fabricated by selective laser melting

Selective laser melting(SLM)can efficiently fabricate metallic components with complex shapes and offers new opportunities for the structural optimization of lightweight components[1].Owing to the high cooling rate(10^(3)-10^(6)Ks^(-1))of the SLM process,the solidified SLM-fabricated metals show a unique microstructure with highly supersaturated solid solutions that are well beyond the normal solubility limits of most elements.This leads to significant improvements in the mechanical properties of the SLM-fabricated materials[2].

An Ultra-High Strength Over 700 MPa in Al-Mn-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting

Selective laser melting(SLM)provides optimized lightweight structures for aircraft and space applications.However,the strength of the current SLMed aluminum alloys is still lower than that of the traditional high-performance aluminum alloys.This study presents an ultra-high-strength Al-Mn-Mg-Sc-Zr aluminum alloy specifically designed for SLM by increasing the(Mg+Mn)and(Sc+Zr)content simultaneously based on the rapid solidification characteristics of the SLM process.The alloy exhibits good SLM processability with a minimum porosity of 0.23%.After aging at 300℃,the strength of the alloy was effectively improved,and the anisotropy of mechanical properties was reduced.Additionally,the tensile yield strength and ultimate tensile strength of the alloy reached 621±41 MPa and 712±28 MPa,respectively;these values are superior to those of most SLMed aluminum alloys reported previously.Multiple strengthening mechanisms including solid solution strengthening,precipitation strengthening and grain refinement strengthening contribute to the high strength of the present alloys.