The effect of support structures on maraging steel MS1 parts fabricated by selective laser melting at different building angles

Abstract

Purpose This study aims to further the understanding of support structures and the likely impacts on maraging steel MS1 parts fabricated by selective laser melting (SLM) at 45°, 60° and 75° building angles. Design/methodology/approach Two groups of samples, one group with support structures and the other group without support structures, were designed with the same specifications and printed under the same conditions by SLM at 45°, 60° and 75° building angles. Differences in dimensional accuracy, surface roughness, Vickers microhardness, residual stress and microstructure were compared between groups. Findings The results showed that with support structures, more accurate dimension and slightly higher Vickers microhardness could be obtained. Larger compressive stress dominated and was more uniformly distributed on the supporting surface. Without support structures, the dimension became more precise as the building angle increased and alternating compressive and tensile stress was unevenly distributed on the supporting surface. In addition, the surface roughness of the outer surface decreased with the increase of the built angle, regardless of the support structures. Furthermore, whether the building angle was 45°, 60° or 75°, the observed microstructures revealed that the support structures altered the orientation of the molten pool and the direction of grain growth. Originality/value This paper studies the influence of support structures on the workpieces printed at different building angles. Support structures affect the residual stress distribution, heat dissipation rate and microstructure of the parts, and thus affecting the printing quality. Therefore, it is necessary to balance the support strategy and printing quality to better apply or design the support structures in SLM.

Effect of remelting processes on the microstructure and mechanical behaviours of 18Ni-300 maraging steel manufactured by selective laser melting

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A Review of Post-Processing Technologies in Additive Manufacturing

“…These defects have serious influences on the internal microstructure and mechanics of the final parts [49][50][51][52][53][54][55]. Therefore, after the parts being manufactured, post-processing operations are usually required to improve the mechanical properties and the surface quality, achieving their intended utilization [56][57][58][59][60][61][62]. There have many post-processing technologies, such as the thermal post-processing method to release thermally-induced residual stress and laser peening to reduce micro-defects and improve surface quality.…”

Effect of the strut size and tilt angle on the geometric characteristics of selective laser melting AlSi10Mg

“…Leary et al (2018) shown that the mechanical properties, deformation and failure modes of Inconel 625 cellular lattice structures manufactured by SLM. Cao et al (2020) and Delcuse et al (2020) studied the effect of structures tilt angle on properties of the SLMed lattice part. Leary et al (2016) provided the manufacturability of lattice strut elements for a series of build inclinations and strut diameters.…”