다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

A review of selective laser melting of aluminum alloys: Processing, microstructure, property and developing trends

Microstructure of selective laser melted AlSi10Mg alloy

Mechanistic models for additive manufacturing of metallic components

The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

An improved fused deposition modeling process for forming large-size thin-walled parts

A three-dimensional model was developed to simulate the radiation heat transfer in the AlSi10Mg packed bed. The volume of fluid method (VOF) was used to capture the free surface during selective laser melting (SLM). A randomly packed powder bed was obtained using discrete element method (DEM) in Particle Flow Code (PFC). The proposed model has demonstrated a high potential to simulate the selective laser melting process (SLM) with high accuracy. In this paper, the effect of the laser scanning speed and laser power on the thermodynamic behavior of the molten pool was investigated numerically. The results show that the temperature gradient and the resultant surface tension gradient between the center and the edge of the molten pool increase with decreasing the scanning speed or increasing the laser power, thereby intensifying the Marangoni flow and attendant turbulence within the molten pool. However, at a relatively high scanning speed, a significant instability may be generated in the molten pool. The perturbation and instability in the molten pool during SLM may result in an irregular shaped track.

Thermal behavior in single track during selective laser melting of AlSi10Mg powder

During selective laser melting (SLM) of K418 powder, the influence of the process parameters, such as laser power P and scanning speed v, on the dynamic thermal behavior and morphology of the melted tracks was investigated numerically. A 3D finite difference method was established to predict the dynamic thermal behavior and flow mechanism of K418 powder irradiated by a Gaussian laser beam. A three-dimensional randomly packed powder bed composed of spherical particles was established by discrete element method. The powder particle information including particle size distribution and packing density were taken into account. The volume shrinkage and temperature-dependent thermophysical parameters such as thermal conductivity, specific heat, and other physical properties were also considered. The volume of fluid method was applied to reconstruct the free surface of the molten pool during SLM. The geometrical features, continuity boundaries, and irregularities of the molten pool were proved to be largely determined by the laser energy density. The numerical results are in good agreement with the experiments, which prove to be reasonable and effective. The results provide us some in-depth insight into the complex physical behavior during SLM and guide the optimization of process parameters.

Thermal dynamic behavior during selective laser melting of K418 superalloy: numerical simulation and experimental verification

Numerical analysis of pileup process in metal microdroplet deposition manufacture

Jun Du

Papers

The AlSi10Mg samples produced by selective laser melting: single track, densification, microstructure and mechanical behavior

An improved fused deposition modeling process for forming large-size thin-walled parts

Thermal behavior in single track during selective laser melting of AlSi10Mg powder

Thermal dynamic behavior during selective laser melting of K418 superalloy: numerical simulation and experimental verification

Numerical analysis of pileup process in metal microdroplet deposition manufacture