Experimental and Numerical Analysis of Residual Stresses in Additive Layer Manufacturing by Laser Melting of Metal Powders

Roberts, Ibiye A.; Wang, Changjiang; Stanford, Mark; Kibble, Kevin A.; Mynors, Diane J.

doi:10.4028/www.scientific.net/kem.450.461

Cited by 19 publications

(26 citation statements)

References 8 publications

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“…According to Kruth et al (Ref 18 ), for the same energy density doubling the layer thickness reduced the curling angle of a bridge geometry by 6%. According to Roberts et al (Ref 17 ), doubling the layer thickness reduced the residual stress by 5%. According to Zaeh et al (Ref 14 ), increasing the layer thickness by 2.5 times decreased the deformation of the ends of a T-shaped cantilever by 82%.…”

Section: Introductionmentioning

confidence: 97%

“…Delgado et al (Ref 31 ) reported that increasing layer thickness had a negative effect on the mechanical properties of AISI 316L SLM components. Parts were created with different layer thicknesses using the same parameters (Ref 12 , 14 , 17 , 18 , 29 - 31 ), optimized for one layer thickness. From the published work, the effect of layer thickness on residual stress and mechanical properties is not well understood.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Processing Parameter Effects on Residual Stress and Mechanical Properties of Selective Laser Melted Ti6Al4V

Ali

Ghadbeigi

Mumtaz

2018

J. of Materi Eng and Perform

116

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Selective laser melting (SLM) process is characterized by large temperature gradients resulting in high levels of residual stress within the additively manufactured metallic structure. SLM-processed Ti6Al4V yields a martensitic microstructure due to the rapid solidification and results in a ductility generally lower than a hot working equivalent. Post-process heat treatments can be applied to SLM components to remove in-built residual stress and improve ductility. Residual stress buildup and the mechanical properties of SLM parts can be controlled by varying the SLM process parameters. This investigation studies the effect of layer thickness on residual stress and mechanical properties of SLM Ti6Al4V parts. This is the first-of-its kind study on the effect of varying power and exposure in conjunction with keeping the energy density constant on residual stress and mechanical properties of SLM Ti6Al4V components. It was found that decreasing power and increasing exposure for the same energy density lowered the residual stress and improved the % elongation of SLM Ti6Al4V parts. Increasing layer thickness resulted in lowering the residual stress at the detriment of mechanical properties. The study is based on detailed experimental analysis along with finite element simulation of the process using ABAQUS to understand the underlying physics of the process.

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Processing Parameter Effects on Residual Stress and Mechanical Properties of Selective Laser Melted Ti6Al4V

Ali

Ghadbeigi

Mumtaz

2018

J. of Materi Eng and Perform

116

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“…In addition, the thermal conductivity of powder is different than the solid material, as the contact area among adjacent particles is smaller. 73 It has been proved that the effective thermal conductivity of powders is a function of multiple factors, such as particle size and shape, solid volume fraction, thermal conductivity of the solid and the thermal conductivity of the gaseous media. 74 Several studies consider constant thermal conductivities, both for the powder and the solid state, in order to reduce the complexity of the model.…”

Section: Numerical Modelingmentioning

confidence: 99%

Simulation of metallic powder bed additive manufacturing processes with the finite element method: A critical review

Schoinochoritis¹,

Chantzis²,

Salonitis

2016

Proceedings of the Institution of Mechanical Engineers, Part B:

271

112

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This article provides a literature review of finite element simulation studies for metallic powder bed additive manufacturing processes. The various approaches in the numerical modeling of the processes and the selection of materials properties are presented in detail. Simulation results are categorized according to three major findings' groups (i.e. temperature field, residual stresses and melt pool characteristics). Moreover, the means used for the experimental validation of the simulation findings are described. Looking deeper into the studies reviewed, a number of future directions are identified in the context of transforming simulation into a powerful tool for the industrial application of additive manufacturing. Smart modeling approaches should be developed, materials and their properties should be further characterized and standardized, commercial packages specialized in additive manufacturing simulation have to be developed and simulation needs to become part of the modern digital production chains. Finally, the reviewed studies are organized in a table and characterized according to the process and material studied, the modeling methodology and the experimental validation method used in each of them. The key findings of the reviewed studies are also summarized.

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“…When creating products by using methods of AM, large temperature gradients and technological residual stresses arise in the volume of the material, resulting in disruption of the product shape, changes in the mechanical and operational characteristics of the object, and its destruction during manufacturing (King et al 2015;Li et al 2010;Ibiye et al 2011;Parry et al 2015;Wu et al 2014;Baufeld et al 2010;Riedlbauer et al 2012). In order to work out the regimes and optimize the technological process, it is advisable to carry out a preliminary modeling of the process of layer-by-layer formation of the product, which boils down to a multivariate solution of thermoconversion problems.…”

Section: Introductionmentioning

confidence: 99%

Numerical 3D simulation of wire deposition process to predict distortion of parts

Smetannikov

Maksimov

Трушников

et al. 2019

Mech Adv Mater Mod Process

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In the work, on the basis of the analysis of publications, existing approaches to the numerical modeling of additive processes of product formation are shown. The work itself is devoted to the study of the influence of parameters of the process of surfacing wire materials on the formation of residual deformations in parts. A mathematical formulation of the non-stationary thermomechanical problem is presented, and algorithms for solving the problem using the technology of birth and death of finite elements in the ANSYS package are described. Verification of the model created by the finite element was carried out on the basis of data from the experiment on surfacing a multilayer sample. The effect on the level of residual warping of the following process parameters was studied: the exposure time before the next layer was deposited; the motion path of the burner; ambient temperature. It is shown that the change in ambient temperature is the most effective way to reduce the residual distortions of the form.

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Experimental and Numerical Analysis of Residual Stresses in Additive Layer Manufacturing by Laser Melting of Metal Powders

Cited by 19 publications

References 8 publications

Processing Parameter Effects on Residual Stress and Mechanical Properties of Selective Laser Melted Ti6Al4V

Processing Parameter Effects on Residual Stress and Mechanical Properties of Selective Laser Melted Ti6Al4V

Simulation of metallic powder bed additive manufacturing processes with the finite element method: A critical review

Numerical 3D simulation of wire deposition process to predict distortion of parts

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