Selective laser melting of Invar 36: Microstructure and properties

Abstract

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A new approach to develop palladium-modified Ti-based alloys for biomedical applications

“…The latter obviously indicate increasingly unstable melt flow with increased laser scanning speed. A similar phenomenon was observed in previous work on SLM of Ti64 and Invar 36 where increases in laser scanning speeds increased the flow velocity and instability of the melt pool [29][30][31]. Unstable melt pools tend to raise material away from the build surfaces rather than allow it to spread steadily along laser scanning direction [29], which is liable to cause development of cave-like pores (Figure 4(e-f)) and elongated pores at the interfaces between layers as observed in Figure 3(c).…”

“…Particularly, when the laser scanning speeds are beyond 3000mm/s, the porosity level increases significantly. Since the porosity development is believed to be associated with melt flow behaviour[29][30][31], the uppermost surface roughness and structure of the as-fabricated samples, which contains information about the melt flow patterns, were also investigated and the results are shown inFigure 4andFigure 5. As Figure 4 shows, the final laser-scanned tracks on the uppermost surfaces of the as-fabricated samples become increasingly irregularly-shaped at the higher laser scanning speeds.…”

In-Built Customised Mechanical Failure of 316L Components Fabricated Using Selective Laser Melting

“…According to ref. [35], decrease in porosity resulted in a significant improvement in elongation. Additionally, set A-having the larger maximum strain-exhibits more of a ductile behaviour by absorbing more energy per unit volume (area under stress-strain curve), and conversely by having a significantly lower maximum strain, set C exhibits a more brittle behaviour with less energy per unit of volume absorbed.…”

The Hardness of Additively Manufactured Alloys

“…Figure 23. An analysis of anisotropic behavior [15] through a comparison between the transverse and longitudinal tensile strengths in additively manufactured (a) stainless steels [2,41,42,44,209] (b) aluminum alloy AlSi10Mg [135,136,[210][211][212][213][214] (c) Ti-6Al-4V [50,53,79,174,[215][216][217][218][219][220][221][222][223][224][225][226] and (d) nickel alloys [227][228][229][230][231][232]. Data points deviating from the dashed one-to-one line are exhibit more anisotropy compared to those lying close to the line.…”