The microstructure and mechanical properties of selectively laser melted AlSi10Mg: The effect of a conventional T6-like heat treatment

Abstract

The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. ABSTRACTSelective laser melting (SLM) of aluminium is of research interest because of its potential benefits to high value manufacturing applications in the aerospace and automotive industries. In order to demonstrate the credibility of SLM Al parts, their mechanical properties need to be studied. In this paper, the nano-, micro-, and macro-scale mechanical properties of SLM AlSi10Mg were examined. In addition, the effect of a conventional T6-like heat treatment was investigated and correlated to the generated microstructure.Nanoindentation showed uniform hardness within the SLM material. Significant spatial variation was observed after heat treatment due to phase transformation. It was found that the SLM material's microhardness exceeded its die-cast counterpart. Heat treatment softened the material, reducing micro-hardness from 125±1 HV to 100±1 HV. An ultimate tensile strength (333 MPa), surpassing that of the die cast counterpart was achieved, which was slightly reduced by heat treatment (12 %) alongside a significant gain in strain-to-failure (~threefold). Significantly high compressive yield strength was recorded for the as-built material with the ability to withstand high compressive strains. The SLM characteristic microstructure yielded enhanced strength under loading, outperforming cast material. The use of a T6-like heat treatment procedure also modified the properties of the material to yield a potentially attractive compromise between the material's strength and ductility making it more suitable for a wider range of 1 E-mail: nesma.aboulkhair@nottingham.ac.uk 2 applications and opening up further opportunities for the additive manufacturing process and alloy combination.

Dynamic compressive response of additively manufactured AlSi10Mg alloy hierarchical honeycomb structures

“…Similar anisotropy has been seen in previous work and ascribed to microstructural anisotropy stemming from the asymmetric heat flux during laser irradiation and cooling and from the preference for flaws to align in this direction [23]. The microstructures of the SLM manufactured AlSi10Mg alloy using the same materials and process as used in this study have been previously reported by Aboulkhair et al [24].…”

Investigation of the effects of different heat treatment parameters on the corrosion and mechanical properties of the AlSi10Mg alloy produced with direct metal laser sintering

“…In addition, the stress and internal stresses that occur in the as‐built structure by rapid solidification are eliminated by SR heat treatment, which causes the material to soften. However, with the loss of MPBs as a result of T6 heat treatment, hardness is further reduced …”

A Review of Metal Fabricated with Laser‐ and Powder‐Bed Based Additive Manufacturing Techniques: Process, Nomenclature, Materials, Achievable Properties, and its Utilization in the Medical Sector

“…[37,[111][112][113][114] Secondly, the scan speed has a noteworthy impact on the shape of the melt pool, with increasing scan speeds the melt pool width decreases, which requires to reduce hatch distances to account for it, while the melt pool length increases. References pure Al >99.5 [143] AlSi0.5 $100 [120] Al6061 (AlMg1SiCu) 96.5 [144] Al7075 (AlZn5.5MgCu) 95.1 [145] Al7075 þ 4 wt% Si 98.9 [145,146] A356 (AlSi7Mg0.3) 99.8 [147] A357 (AlSi7Mg0.6) 99.5 [148] A360 (AlSi9.5Mg0.5) 99.8 [146] AlSi10Mg 99.5 %100 [36,64,73,115,120,122,131,137,[149][150][151][152][153] AlSi25 %100 [120] AlMg3 %100 [120] AlSi9Cu3 99.5 [137] Al-3.5Cu-1.5Mg-1Si >98 [154] AlMgScZr (Scalmalloy) >99 %100 [100,116,137] AlSi10Mg reinforced with 5 wt% TiC 99.5 [155] AlSi10Mg reinforced with 1 wt% TiB 2 99.2 [152] AlSi10Mg reinforced with 10 wt% TiB 2 98 [152] AlSi10Mg reinforced with 0.5 wt% MgAl 2 O 4 99.3 [152] a) common relates to consistent results found in multiple publications. In addition to the complexity of determining a suitable set of fabrication parameters, various raw materials differ widely in their requirements and their absorptivity of the laser power, and their heat conductivity.…”