Author:
Li Lan,Pan Tan,Zhang Xinchang,Chen Yitao,Cui Wenyuan,Yan Lei,Liou Frank
Abstract
Purpose
During the powder bed fusion process, thermal distortion is one big problem owing to the thermal stress caused by the high cooling rate and temperature gradient. For the purpose of avoiding distortion caused by internal residual stresses, support structures are used in most selective laser melting (SLM) process especially for cantilever beams because they can assist the heat dissipation. Support structures can also help to hold the work piece in its place and reduce volume of the printing materials. The mitigation of high thermal gradients during the manufacturing process helps to reduce thermal distortion and thus alleviate cracking, curling, delamination and shrinkage. Therefore, this paper aims to study the displacement and residual stress evolution of SLMed parts.
Design/methodology/approach
The objective of this study was to examine and compare the distortion and residual stress properties of two cantilever structures, using both numerical and experimental methods. The part-scale finite element analysis modeling technique was applied to numerically analyze the overhang distortions, using the layer-by-layer model for predicting a part scale model. The validation experiments of these two samples were built in a SLM platform. Then average displacement of the four tip corners and residual stress on top surface of cantilever beams were tested to validate the model.
Findings
The validation experiments results of average displacement of the four tip corners and residual stress on top surface of cantilever beams were tested to validate the model. It was found that they matched well with each other. From displacement and residual stress standpoint, by introducing two different support structure, two samples with the same cantilever beam can be successfully printed. In terms of reducing wasted support materials, print time and high surface quality, sample with less support will need less post-processing and waste energy.
Originality/value
Numerical modeling in this work can be a very useful tool to parametrically study the feasibility of support structures of SLM parts in terms of residual stresses and deformations. It has the capability for fast prediction in the SLMed parts.
Subject
Industrial and Manufacturing Engineering,Mechanical Engineering
Reference49 articles.
1. Numerical and experimental investigations on laser melting of stainless steel 316L metal powders;Journal of Manufacturing Processes,2014
2. A novel approach to support structures optimized for heat dissipation in SLM by combining process simulation with topology optimization,2019
3. The achievable mechanical properties of SLM produced maraging steel 300 components;Rapid Prototyp. J,2016
4. Investigationon reducing distortion by preheating during manufacture of aluminum partsusing selective laser melting;J. Laser Appl,2014
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