Selective Laser Melting Additive Manufacturing of Novel Aluminum Based Composites With Multiple Reinforcing Phases

Abstract

The selective laser melting (SIM), due to its unique additive manufacturing (AM) proc essing manner and laser-induced nonequilibrium rapid melting!solidification mechanism, has a promising potential in developing new metallic materials with tailored perform ance. In this work, SLM of the SiCIAlSilOMg composites was performed to prepare the Al-based composites with the multiple reinforcing phases. The influence of the SLM processing parameters on the constitutional phases, microstructural features, and mechanical peiformance (e.g., densification, microhardness, and wear property) of the SLM-processed Al-based composites was studied. The reinforcing phases in the SLMprocessed Al-based composites included the unmelted micron-sized SiC particles, the in situ formed micron-sized AUSiC4 strips, and the in situ produced submicron AfSiC4 particles. As the input laser energy density increased, the extent of the in situ reaction between the SiC particles and the Al matrix increased, resulting in the larger degree of the formation of Al4 SiC4 reinforcement. The densification rate of the SLM-processed Al-based composite parts increased as the applied laser energy density increased. The sufficiently high density (~96% theoretical density (TD)) was achieved for the laser linear energy density larger than 1000 Jim. Due to the generation of the multiple rein forcing phases, the ele vated mechanical properties were obtained for the SLM-processed Al-based composites, showing a high microhardness of 214 HVg j, a considerably low coefficient of friction (COF) of 0.39. and a reduced wear rate of 1.56 x 10 5 mm3 N 1 m~. At an excessive laser energy input, the grain size of the in situ formed AfSiC4 rein forcing phase, both the strip-and particle-structured AI4SiC4, increased markedly. The significant grain coarsening and the formation of the inteifacial microscopic shrinkage porosity lowered the mechanical properties of the SLM-processed Al-based composites. These findings in the present work are applicable and/or transferrable to other laserbased powder processing processes, e.g., laser cladding, laser metal deposition, or laser engineered net shaping.

Prediction of porosity in metal-based additive manufacturing using spatial Gaussian process models

“…The body of the literature on SLM is quite large, studying the fabrication of different metallic materials such titanium alloys [7,33,34], aluminum alloys [35][36][37], and nickel alloys [38,9,39]. We consider the SLM of steel in this study, which has been frequently studied.…”

Selective Laser Melting Additive Manufacturing of Hard-to-Process Tungsten-Based Alloy Parts With Novel Crystalline Growth Morphology and Enhanced Performance

“…The worn surface experienced the sufficient plastic deformation at a temperature below its recrystallization temperature. The material strengthening was expected to occur, due to the movement and pinning of dislocations within the crystalline structure of the material, which was known as strain-hardened tribolayer [41,42]. The formation of significantly refined cellular dendritic crystals of W-based alloy part (Fig.…”

On process-step parallel computability and linear superposition of mechanical responses in additive manufacturing process simulation

“…Megahed et al [13] classify existing metal AM processes based on the manner in which the material is deposited prior to fusion, referring to powder-bed, blown-powder, and wire-feed processes. The predominant metal AM technology is selective laser melting (SLM), a powder bed process [14][15][16][17][18]. In general, metal AM technology is characterized by a localized heat (energy) input directed in such a way as to (at least partially) melt and fuse the deposited material with the existing structure.…”