Thermal Analysis of Additive Manufacturing

COMSOL Conference October 7-10, 2014

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Motivation

• Additive manufacturing (3D Printing) – Direct material deposit – Rapid manufacture/prototype – Complex geometry – Reduced machining

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http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=_HVrKOE_xLuz2M&tbnid=lb33tMqEgt0rUM:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.eos.info%2Faerospace&ei=7kU2VI6tOq2asQTakYHABQ&bvm=bv.76943099,d.aWw&psig=AFQjCNF4EszQaLWJ_yj1fCfsNtmP10QY1g&ust=1412929294795208http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=bYijUHdmTCr0lM&tbnid=u7Bv86DGKX1c-M:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.rdmag.com%2Faward-winners%2F2012%2F08%2Fthumbs-additive-manufacturing&ei=b0k2VImZJOLesASxtoHIDw&bvm=bv.76943099,d.aWw&psig=AFQjCNEvRUwtPeFBoUIdqXco6AAmowFJXg&ust=1412930251168809

Process

• Discrete layer addition • 95% of AM manufactured by Powder Bed Fusion

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http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=SyofdZA6ipBP9M&tbnid=sFuCYDznphSpyM:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.metal-am.com%2Fintroduction_to_metal-additive_manufacturing%2Fprocesses%3Faccept_cookies%3D1&ei=T0g2VPO7D4TksASv-oKgBw&bvm=bv.76943099,d.aWw&psig=AFQjCNHJjxTciz80NBhmQKXjO_vCHkuF9w&ust=1412929760228959

AM Model

• Time dependent material addition

• Moving heat source

• Heat flow – Conduction through

bulk – Convection in molten

metal pool – Radiation to

environment

• Phase change: – Liquid to Solid – Solid to Liquid – Solid state

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Analysis

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Ti-6Al-4V

Conditions: Zhiqiang Fan and Frank Liou (2012

Marangoni Convection

• Surface tension gradient due to: – Temperature

distribution – Species concentration

• Mass transfer away from regions of low surface tension

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http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=LqA77gpHmXGHeM&tbnid=_H9jLMWRidfSFM:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.comsol.com%2Fmodel%2Fmarangoni-convection-110&ei=E042VN_1MJOtyASGtIGoCw&bvm=bv.76943099,d.aWw&psig=AFQjCNF7LhS_7EfRSCtxQNG04byQMy7P1Q&ust=1412931314377461

Temperature/Flow Transient

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Including Marangoni Effect

Influence of Marangoni Effect

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Temperature on layer 1

Layer 1 Layer 2 Layer 3

Influence of Marangoni Effect

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Temperature on layer 2 Temperature on layer 3

Layer 3 Layer 2 Layer 3

Conclusions

• Marangoni effect important for local temperature distribution close to molten metal pool

• Marangoni induced convection is significantly reduced away from molten metal pool

• For complex components containing multiple layers the effect is minimal

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Thermal Analysis of Additive ManufacturingMotivationProcessAM ModelAnalysisMarangoni ConvectionTemperature/Flow TransientInfluence of Marangoni EffectInfluence of Marangoni EffectConclusions