Additive manufacturing of an oxide ceramic by laser beam melting—Comparison between finite element simulation and experimental results

Abstract

et al.. Additive manufacturing of an oxide ceramic by laser beam melting-Comparison between finite element simulation and experimental results. Abstract: Recent progress in the application of Laser Beam Melting (LBM) of oxide ceramics has shown promising results. However, a deeper understanding of the process is required to master and control the track development. In this approach numerical modeling could allow higher quality, of additive manufacturing for such materials, to be achieved. The validation of an earlier developed finite element model for LBM of ceramic materials has been established through a comparison with experimental results. The model solves heat and mass transfers whilst accounting for fluid flow due to surface tension and Marangoni convection, as well as tracking the material/gas boundary. The volumetric heat source parameters used in the simulations have been calibrated with an analytical model combined with original in-situ reflectance measurements. Numerical results show good agreement with measurements of melt pool dimensions and shapes. They also provide a coherent description of the evolution of the track morphology when varying the heat source parameters. Track irregularities have also been revealed by simulations at high scanning speed and the balling effect highlighted and explained through similar simulations.

Ultrahigh-temperature melt printing of multi-principal element alloys

“…To achieve a high heating temperature for rapid multi-elemental melting/ mixing during printing, focused high-energy sources (e.g., lasers, electron beam, electric arc) are commonly used to interact and melt metal powders into dense products [20][21][22] . The relatively rapid cooling rate of these methods can effectively prevent the formation of undesired intermetallic phases [23][24][25] . While the temperature of these heating sources is sufficiently high to melt a wide range of elements, these approaches can only achieve a small-sized melt zone (e.g., the laser beam diameter is usually only ~100 µm), which results in a highly uneven temperature distribution [26][27][28] .…”

Determining the feasible conditions for processing lunar regolith simulant via laser powder bed fusion

“…[42] and Fateri et al [19] tested lunar regolith simulant with an emission power level of 50 W. Thus, this suggests that there is a threshold value of power beyond which lunar regolith simulant may not be deposited stably (even if the energetic input is regulated by increasing the scan speed). In comparison with ceramic materials typically processed using laser powder bed fusion, which are often susceptible to crack formation due to their weak thermal shock resistance, NU-LHT-2M did not show the presence of cracks on the deposited specimen [43]. Thus, the use of preheating systems which are often employed for the processing of ceramics to reduce thermal gradients and solidification rates [44,45], appears not to be required for the deposition of the lunar regolith simulant.…”

Effect of processing parameters during the laser beam melting of Inconel 738: Comparison between simulated and experimental melt pool shape

“…(1), a function of √ . On the contrary, Moniz et al (2019), in a study of LBM process applied to ceramic materials, proposed a model in which the melt pool dimensions do not depend on the peak temperature, but rather on the linear density of energy absorbed by the material, . However, it should be noted for ceramic material that the incident energy of the laser beam accumulates in the material due to low thermal diffusion.…”