Effect of thermal characteristics on distortion in laser cladding of AISI 316L

Abstract In laser cladding process, the inhomogeneous temperature distribution and the rapid thermal cycle can lead to accumulation of thermal distortion and dimensional errors. The mechanism of thermal distortion during the cladding process is not clear. The purpose of this study is to in-situ monitor the temperature by IR camera and thermocouples and to correlate the extracted thermal characteristics to the distortion of the parts during laser cladding of AISI 316 L. Experiments were conducted to investigate the effect of laser power, scanning speed, powder feeding rate and substrate thickness on the distortion. The distortion rate was acquired from the overall distortion curve. Results showed that the distortion rate did not change with scanning speed. Process thermal characteristics, including spatial temperature gradient and heating area, were extracted from the thermal signatures. The multiple sensor monitoring and extraction algorithm can provide a clear view of the whole part in three directions during the process. The temperature gradient of the parts was a complex vector field when variable process parameters were chosen. Both the temperature gradient and the heating area had an effect on the magnitude of distortion. An analytical model considering the influence of the heating area was applied to predict the angular distortion.

[1]  Amir Khajepour,et al.  Real-time control of microstructure in laser additive manufacturing , 2016 .

[2]  Shaw C. Feng,et al.  A review on measurement science needs for real-time control of additive manufacturing metal powder bed fusion processes , 2017, Int. J. Prod. Res..

[3]  A. Khajepour,et al.  Effect of real-time cooling rate on microstructure in Laser Additive Manufacturing , 2016 .

[4]  M. Mochizuki,et al.  Temperature distribution effect on relation between welding heat input and angular distortion , 2017 .

[5]  Brendan P. Croom,et al.  Revealing mechanisms of residual stress development in additive manufacturing via digital image correlation , 2018, Additive Manufacturing.

[6]  Tarasankar DebRoy,et al.  An improved prediction of residual stresses and distortion in additive manufacturing , 2017 .

[7]  Pan Michaleris,et al.  Effect of inter-layer dwell time on distortion and residual stress in additive manufacturing of titanium and nickel alloys , 2015 .

[8]  Weidong Huang,et al.  In situ measurements and thermo-mechanical simulation of Ti–6Al–4V laser solid forming processes , 2019, International Journal of Mechanical Sciences.

[9]  J. S. Zuback,et al.  Additive manufacturing of metallic components – Process, structure and properties , 2018 .

[10]  V. Ocelík,et al.  In-situ strain observation in high power laser cladding , 2009 .

[11]  M. Kottman,et al.  Experimental study and modeling of H13 steel deposition using laser hot-wire additive manufacturing , 2016 .

[12]  Sergey N. Grigoriev,et al.  Parametric analysis of SLM using comprehensive optical monitoring , 2016 .

[13]  P. Michaleris,et al.  In situ monitoring and characterization of distortion during laser cladding of Inconel® 625 , 2015 .

[14]  Sergey N. Grigoriev,et al.  Definition of brightness temperature and restoration of true temperature in laser cladding using infrared camera , 2013 .

[15]  A. De,et al.  Spatial variation of melt pool geometry, peak temperature and solidification parameters during laser assisted additive manufacturing process , 2015 .

[16]  Pan Michaleris,et al.  3D spatial reconstruction of thermal characteristics in directed energy deposition through optical thermal imaging , 2015 .

[17]  I. Smurov,et al.  Study of the laser melting of pre-deposited intermetallic TiAl powder by comprehensive optical diagnostics , 2017 .

[18]  Ming Gao,et al.  The Effect of Deposition Patterns on the Deformation of Substrates During Direct Laser Fabrication , 2013 .

[19]  Timothy W. Simpson,et al.  Development of experimental method for in situ distortion and temperature measurements during the laser powder bed fusion additive manufacturing process , 2016 .

[20]  Norbert Pirch,et al.  Investigation on reducing distortion by preheating during manufacture of aluminum components using selective laser melting , 2014 .

[21]  T. Ueda,et al.  Study on deformation restraining of metal structure fabricated by selective laser melting , 2017 .

[22]  Xin Lin,et al.  In-situ observation and numerical simulation on the transient strain and distortion prediction during additive manufacturing , 2019, Journal of Manufacturing Processes.

[23]  Junqiang Wang,et al.  A Plane Stress Model to Predict Angular Distortion in Single Pass Butt Welded Plates With Weld Reinforcement , 2017 .

[24]  Jerome Solberg,et al.  Implementation of a thermomechanical model for the simulation of selective laser melting , 2014 .

[25]  Amitava De,et al.  Mitigation of thermal distortion during additive manufacturing , 2017 .

[26]  Z. Yao,et al.  An analytical formula for estimating the bending angle by laser forming , 2006 .

[27]  Michael Rethmeier,et al.  In-situ distortions in LMD additive manufacturing walls can be measured with digital image correlation and predicted using numerical simulations , 2018 .

[28]  Zhenqiang Yao,et al.  Temperature gradient mechanism in laser forming of thin plates , 2007 .