Thermal behavior and densification mechanism during selective laser melting of copper matrix composites: Simulation and experiments

Dai, Donghua; Gu, Dongdong

doi:10.1016/j.matdes.2013.10.006

Cited by 255 publications

(77 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most widely-cited single layer stress models using finite element analysis are those developed by Hussein et al [21], Matsumoto et al [18], Contuzzi et al [45] and Dai and Gu [59]. Wu et al [60] proposed a model that analyzed the stresses within a single layer of powder as it solidifies, unlike the others, which were based on stresses within the solid materials.…”

Section: Stress and Distortion Modelsmentioning

confidence: 99%

“…These controls primarily consisted of chamber temperature control, using inert gases to prevent oxidation and reduce temperature gradients in the powder bed. Jia and Gu [94], Dai and Gu [59] and Dadbakhsh et al [95] looked at the effect of having oxygen in the environment during printing and ways to eliminate it. Dai and Gu and Dadbakhsh et al suggested running an inert gas through the powder bed during the process to prevent oxidation between the layers of the part and produce a more uniform temperature throughout.…”

Section: Process Environment Controlmentioning

confidence: 99%

See 1 more Smart Citation

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

2017

View full text Add to dashboard Cite

Abstract:A useful and increasingly common additive manufacturing (AM) process is the selective laser melting (SLM) or direct metal laser sintering (DMLS) process. SLM/DMLS can produce full-density metal parts from difficult materials, but it tends to suffer from severe residual stresses introduced during processing. This limits the usefulness and applicability of the process, particularly in the fabrication of parts with delicate overhanging and protruding features. The purpose of this study was to examine the current insight and progress made toward understanding and eliminating the problem in overhanging and protruding structures. To accomplish this, a survey of the literature was undertaken, focusing on process modeling (general, heat transfer, stress and distortion and material models), direct process control (input and environmental control, hardware-in-the-loop monitoring, parameter optimization and post-processing), experiment development (methods for evaluation, optical and mechanical process monitoring, imaging and design-of-experiments), support structure optimization and overhang feature design; approximately 143 published works were examined. The major findings of this study were that a small minority of the literature on SLM/DMLS deals explicitly with the overhanging stress problem, but some fundamental work has been done on the problem. Implications, needs and potential future research directions are discussed in-depth in light of the present review.

show abstract

Section: Stress and Distortion Modelsmentioning

confidence: 99%

Section: Process Environment Controlmentioning

confidence: 99%

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

2017

View full text Add to dashboard Cite

show abstract

“…The most widely cited single layer stress models using finite element analysis are those developed by Hussein et al [21], Matsumoto et al [18], Contuzzi et al [45], Dai & Gu [59]. Wu et al [60] proposed a model that analyzed the stresses within a single layer of powder as it solidifies, unlike the others, which were based on stresses within the solid materials.…”

Section: Stress and Distortion Modelsmentioning

confidence: 99%

“…These controls primarily consisted of chamber temperature control, using inert gases to prevent oxidation and reduce temperature gradients in the powder bed. Jia & Gu [93], Dai & Gu [59], and Dadbakhsh et al [94] looked at the effect of having oxygen in the environment during printing and ways to eliminate it.…”

Section: Process Environment Controlmentioning

confidence: 99%

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

Patterson¹,

Messimer²,

Farrington³

2017

Preprint

View full text Add to dashboard Cite

A useful and increasingly common additive manufacturing (AM) process is the selective laser melting (SLM) or direct metal laser sintering (DMLS) process. SLM/DMLS can produce fulldensity metal parts from difficult materials, but it tends to suffer from severe residual stresses introduced during processing. This limits the usefulness and applicability of the process, particularly in the fabrication of parts with delicate overhanging and protruding features. The purpose of this study was to examine the current insight and progress made toward understanding and eliminating the problem in overhanging and protruding structures. To accomplish this, a survey of literature was undertaken, focusing on process modeling (general, heat transfer, stress and distortion, and material models), direct process control (input and environmental control, hardware-in-the-loop monitoring, parameter optimization, and post-processing), experiment development (methods for evaluation, optical and mechanical process monitoring, imaging, and design-of-experiments), support structure optimization, and overhang feature design; approximately 140 published works were examined. The major findings of this study were that a small minority of the literature on SLM/DMLS deals explicitly with the overhanging stress problem, but some fundamental work has been done on the problem. Implications, needs, and potential future research directions are discussed in-depth in light of the present review.

show abstract

“…Melt pool is also depicted and analyzed in a certain cross section. Figure 1 is a schematic representation of heat transfer in SLM process [12] . The laser scans on the top of the powder bed follow a prescribed scan pattern.…”

mentioning

confidence: 99%

Temperature field simulations during selective laser melting process based on fully threaded tree

2017

View full text Add to dashboard Cite

Selective laser melting (SLM) is the commonly term to describe the process in which a high energy laser beam scans the surface of a metal powder bed and the melted powder solidifies to form the bulk part [1] . SLM make it possible to create final function parts without post processing steps. Manufacturing businesses aiming to deliver their new products more quickly increasingly employ selective laser sintering/melting (SLS/SLM) for fabricating high quality, low cost, repeatable, and reliable alloy powdered parts for automotive, aerospace, and aircraft applications [2] . SLS can indirectly form integral control-shaped capsule for hot isostatic pressing (HIP) and mould core for casting, and SLM can directly and rapidly form HIP-shaped capsule [3] . SLM is complicated because of its high laser scan velocity and phase transformation in a sharply short time. Temperature field in this process is inhomogeneous [4][5][6] . Meanwhile, temperature evolution history would have significant Abstract: Selective laser melting (SLM) is a promising technique for additive manufacturing. During SLM of metallic powder, the temperature field and thermal history are important to understand physical phenomena involved. The purpose of this study is to simulate the temperature field during the SLM process of a hollow cylinder shape part based on a fully threaded tree (FTT) technique, and to analyze the temperature variation with time in different regions of the part. A revised model for temperature field simulation in the SLM process was employed, which includes the transition of powder-to-dense sub-model and a moving volumetric Gaussian distribution heat source sub-model. The FTT technique is then adopted as an adaptive mesh strategy in the simulation. The simulation result shows that during the SLM process of cylinder part, the temperature of inner powder bed is obviously higher than external one. The temperature at the internal of the molten pool is also higher than external, which may lead to differences in microstructures and other properties between the two regions.Key words: fully threaded tree; selective laser melting; temperature distribution; numerical simulation effects on final quality of parts. Large temperature gradients increase residual stresses and distortion and even lead to cracks in parts. Therefore, it is significant for SLM researchers to understand the mechanism of this process and effects of the parameters. Experiments regarding temperature fields, which greatly influence the formation of defects during the process, are lacking. It is a difficult work for most researchers to gain the detailed temperature field and its history during SLM process based on present experiment conditions. So, numerical simulation plays a significant role in the study of thermal behaviour during SLM process. The aim to perform temperature field simulation of SLM processes is to reduce the experimental cost, reveal the transient thermal history that cannot be obtained by limited experiment, and understand the evolution of microstructure...

show abstract

Thermal behavior and densification mechanism during selective laser melting of copper matrix composites: Simulation and experiments

Cited by 255 publications

References 43 publications

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

Overhanging Features and the SLM/DMLS Residual Stresses Problem: Review and Future Research Need

Temperature field simulations during selective laser melting process based on fully threaded tree

Contact Info

Product

Resources

About