While significant progress has been made in laser powder bed fusion (L-PBF) for metal additive manufacturing (AM), there is still limited large scale adoption of this advanced manufacturing techniq

Laser powder bed fusion for metal additive manufacturing: perspectives on recent developments

Magnesium (Mg) alloy shows great potential as bone implant owing to its favourable biocompatibility and degradability. In the present work, bioglass-reinforced Mg-based composite was manufactured v...

https://www.tandfonline.com/doi/pdf/10.1080/17452759.2020.1748381

Laser additive manufacturing of Mg-based composite with improved degradation behaviour

Effect of heat treatment on microstructure, hardness and corrosion resistance of 7075 Al alloys fabricated by SLM

The laser-based powder bed fusion (LBPF) process or commonly known as selective laser melting (SLM) has made significant progress since its inception. Initially, conventional materials like 316L, Ti6Al4V, and IN-718 were fabricated using the SLM process. However, it was inevitable to explore the possible fabrication of the second most popular structural material after Fe-based alloys/steel, the Al-based alloys by SLM. Al-based alloys exhibit some inherent difficulties due to the following factors: the presence of surface oxide layer, solidification cracking during melt cooling, high reflectivity from the surface, the high thermal conductivity of the metal, poor flowability of the powder, low melting temperature, etc. Researchers have overcome these difficulties to successfully fabricate the different Al-based alloys by SLM. However, there exists no review dealing with the fabrication of different Al-based alloys by SLM, their fabrication issues, microstructure, and their correlation with properties in detail. Hence, the present review attempts to introduce the SLM process followed by a detailed discussion about the processing parameters that form the core of the alloy development process. This is followed by the current research status on the processing of Al-based alloys and microstructure evaluation (including defects, internal stresses, etc.), which are dealt with on the basis of individual Al-based series. The mechanical properties of these alloys are discussed in detail followed by the other important properties like tribological properties, fatigue properties, etc. Lastly, an outlook is given at the end of this review.

Selective Laser Melting of Aluminum and Its Alloys.

https://hal.archives-ouvertes.fr/hal-02911059/document

A review of microstructural changes occurring during FSW in aluminium alloys and their modelling

Investigation of porosity reduction, microstructure and mechanical properties for joining of selective laser melting fabricated aluminium composite via friction stir welding

Influence of pulse energy density in micro laser weld of crack sensitive Al alloy sheets

Hybrid laser-TIG welding of dissimilar ferrous steels: 10 mm thick low carbon steel to 304 austenitic stainless steel

Friction stir welding is a solid-state welding technology capable of joining metal parts without melting. The microstructure of the material evolved during the process from columnar grain along the thermal gradient in the melt pool to fine equiaxed grains. A significant decrease in microhardness in the stir zone was observed with the lowest hardness at approximately 3 mm from the weld centre. The decrease in the microhardness is mainly attributed to the dissolution of hardening precipitates in the aluminium matrix. Defects in the weld were observed due to insufficient heat input. Heat input could be increased with the increase in rotational speed of the welding tool, with some improvements in strength.

Joining of 3D-printed AlSi10Mg by friction stir welding

In recent years, additive manufacturing techniques have attracted much research attention because of their ability to fabricate customised parts with complex geometry. The range of composites suitable for laser-based powder bed fusion technique is limited, and has not been investigated yet. This paper aims to study the fabrication of AlSi10Mg reinforced with nAl2O3 using the laser-based powder bed fusion technique.,An experimental approach was used to investigate the densification of AlSi10Mg–nAl2O3 composites using laser-based powder bed fusion technique. Optimisation of the porosity was performed, and microstructure evolution was evaluated.,In this study, laser volumetric energy density (approximately 109 J/mm3) was found to be required for the fabrication of AlSi10Mg–nAl2O3 composites with a relative volumetric density approximating 99%. The use of laser volumetric energy density resulted in larger grains. Columnar grain structure was observed via the use of electron backscatter diffraction mapping.,This paper examines the processing of new aluminium composite material suitable for the fabrication via the laser-based powder bed fusion technique.

Hui-Chi Chen

Papers

Investigation of porosity reduction, microstructure and mechanical properties for joining of selective laser melting fabricated aluminium composite via friction stir welding

Influence of pulse energy density in micro laser weld of crack sensitive Al alloy sheets

Hybrid laser-TIG welding of dissimilar ferrous steels: 10 mm thick low carbon steel to 304 austenitic stainless steel

Joining of 3D-printed AlSi10Mg by friction stir welding

Effect of nAl2O3 on the part density and microstructure during the laser-based powder bed fusion of AlSi10Mg composite