Emilie Hørdum Valente

Technical University of Denmark | DTU · Department of Mechanical Engineering

The present work explores for the first time additive manufacturing of powder mixtures consisting of Chromium Nitride (Cr2N) and AISI 316L with laser powder bed fusion (L-PBF). The addition of 2.5 wt% Cr2N to an AISI 316L powder resulted in the successful dissolution of both chromium and nitrogen into a fully austenitic stainless steel microstructu...

Laser powder bed fusion (L-PBF) was utilized to produce specimens in Ti-6Al-4V, which were subjected to a bi-lamellar heat treatment, which produces microstructures consisting of primary α-lamellae and a fine secondary α-phase inside the inter-lamellar β-regions. The bi-lamellar microstructure was obtained as (i) a direct bi-lamellar heat treatment...

The effect of the scanning strategy during selective laser melting (SLM) of Ti-6Al-4V was investigated. An optimized cellular scan strategy (island scan modeled) was compared to a simple cellular scan strategy (island scan stripes) and a simple antiparallel line scanning strategy (line scan). Surface texture was investigated by optical three-dimens...

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The present work focuses on the effect of heat treatment and surface hardening on the microstructure, wear characteristics and corrosion resistance, of 316L stainless steel produced by Selective Laser Melting (SLM). Specifically, the high temperature treatments austenitisation, high temperature solution nitriding (HTSN) and a new "active austenitis...

Most commercially available laser powder bed fusion (L-PBF) systems are limited to process one material at a time. The ability to spatially apply multiple materials within the same component will strongly expand the available design space for engineers. A typical problem with multi-material components is stress concentration at discrete material in...

The present work focuses on the influence of the composition of the protective gas (argon or nitrogen) used in laser-based powder bed fusion (L-PBF) on the nitrogen content, microstructure and hardness of AISI 316L austenitic stainless steel. L-PBF of AISI 316L powder using Ar gas resulted in loss of nitrogen in the final part. On the other hand, L...

The microstructure of parts produced by sective laser melting of Ti-6Al-4V is typically martensite in elongated prior  grains, which leads to anisotropic mechanical properties. A heat treatment can reduce this anisotropy by making these grains more equiaxed. In this work, simulations are performed wherein the evolution of the microstructure during...

The present work focuses on gaseous thermochemical treatment of stainless steel parts produced by Selective Laser Melting (SLM). Specifically, high temperature solution nitriding (HTSN) and low temperature surface nitriding (LTSN) of SLM 316L stainless steel samples are investigated. The cellular structure and the fusion-boundaries present in the a...