Research on metallurgical bonding of selective laser melted AlSi10Mg alloy

Abstract

The densification behavior, surface morphology and attendant microstructural characteristics of the selective laser melting (SLM) processed AlSi10Mg alloy affected by the processing parameters were systematically investigated. Increasing the laser scanning speed or hatch spacing will deteriorate the metallurgical bonding between melt pools, resulting in the increase of irregular pores. Scanning speed and hatch spacing affect the liquid metallurgical bonding of melt pools in different ways. By manipulating scanning speed, the shape of the melt pool changes, resulting in different extents of metallurgical bonding. Whereas hatch spacing influences the resultant metallurgical bonding by controlling the overlapping rate between neighboring scan tracks simply. The formations of the hierarchical microstructures which discriminated by the Si phase are elucidated. Coarse zones are formed by the instantaneous existence of extremely high ratio of thermal gradient (G) and solidification rate (R) at the melt pool boundary, where solidification microstructure grows planar. Fine zones are formed by columnar-dendritic growth of microstructure. During the solidification process, the contraction forces that generated by the trapped gas in the pores and gravity are applied to the liquid around irregular pores and, forms the porous microstructures different from that in dense areas eventually. The tensile tests reveal that the tensile properties of SLM-processed samples are significantly affected by the formation of porosity.

Anisotropic Thermal Conductivity of Nickel-Based Superalloy CM247LC Fabricated via Selective Laser Melting

“…Samples manufactured by SLM with metallic powder have a higher elastic modulus in the in-plane direction compared with the cross-plane direction [11]. In the manufacturing process, thermal stress accumulates as a result of rapid heating and cooling [34], or flat pores are generated because of the low energy density [35,36] between layers. These defects result in a higher elastic modulus in the in-plane direction than in the cross-plane direction [11,14].…”

“…Gas is trapped in the pores during manufacturing. Irregular pores are formed between the layers because of the gas contraction force and gravity during rapid heating and cooling [36]. The ellipsoid pores expand because of the high gas temperature.…”

Enhancing the acoustic emission technique using fuzzy artificial bee colony-based deep learning for characterizing selective laser melted AlSi10Mg specimens

“…SLM has several advantages over conventional mechanical manufacturing processes, including design freedom, which enables the production of components with complex shapes that would be difficult to produce using conventional methods (Zou et al, 2019). It improves component strength and density, reduces waste by using the exact amount of material for each layer, and allows design freedom and manufacturing flexibility, which are essential in the current industrial sector (Read et al, 2015;Dong et al, 2020).…”

The influence of AlSi10Mg recycled powder on corrosion-resistance behaviour of additively manufactured components: mechanical aspects and acoustic emission investigation

“…Revilla et al [12] has studied the corrosion behaviour of AlSi10Mg alloy and have evidently proved the same. Moreover, it has become one of the most applicable Al alloys for the SLM technique, due to its excellent welding performance, good melt fluidity, low Coefficient of Thermal Expansion (CTE) and high recycling potential, as indicated by Porter [13] and Dong et al [14]. Experimental work by Maamoun et al has showed the recycling potential of AlSi10Mg in particular [15].…”