Thermomechanical behavior of laser metal deposited Inconel 718 superalloy over a wide range of temperature and strain rate: Testing and constitutive modeling

Abstract The lack of comprehensive insight and accurate description on the dynamic thermomechanical behaviors in high-temperature and high-strain-rate loading environment could be one of the major obstacles to extend the laser metal deposited (LMD) Inconel 718 to engineering applications in aeroengine. In this study, to obtain in-depth understanding of plastic flow behavior of the LMD Inconel 718, uniaxial compressive experiments were conducted over a wide range of temperature (298–1273 K) and strain rate (0.001–5300/s). Based on a great number of experimental results, not only the anisotropy of compressive property, but the dependence of the plastic flow stress on temperature and strain rate were investigated systematically. The flow stress of the as-deposited alloy in laser scanning direction is higher than that in depositing direction, which is attributed to the columnar grains epitaxially growing along the build direction and featuring the high length-diameter ratio within the as-deposited sample. Since the small-size precipitates in the under-aged (as-deposited) Inconel 718 alloy could be cut by the moving dislocations directly during plastic deformation, they have various effect on the interaction between moving dislocations and interstitial elements at different strain rate. The third-type of strain aging (3rd SA) effect, exhibiting an anomalous bell-shaped flow stress vs. temperature relation, was observed more apparently than that in the post-aged Inconel 718 reported by other literatures. As for the strain-rate effect, the flow stress of the alloy exhibits inconspicuous strain-rate sensitivity over the range of strain rate below ∼103/s, while increases sharply with the strain rate once it exceeds ∼103 /s. Finally, taking into account the mechanical anisotropy, as well as the anomalous temperature and strain rate sensitivities of the flow stress, we developed a constitutive model based on a physical frame. In this model, an anisotropy component was introduced to consider the effective size of columnar grains in the corresponding loading direction, the strain rate hardening was enhanced as the strain rate gets close to a certain level, and a normal distribution with temperature was used to describe the 3rd SA effect. The developed model was shown to be able to accurately reproduce the plastic flow behavior of the LMD Inconel 718 over a wide range of temperature and strain rate.

[1]  Ming Gao,et al.  The microstructure and mechanical properties of deposited-IN718 by selective laser melting , 2012 .

[2]  M. Bambach,et al.  Hot workability and microstructure evolution of the nickel-based superalloy Inconel 718 produced by laser metal deposition , 2018 .

[3]  David L. McDowell,et al.  Microstructure-sensitive modeling of polycrystalline IN 100 , 2008 .

[4]  M. Weaver,et al.  Activation energy calculations for discontinuous yielding in Inconel 718SPF , 2001 .

[5]  A. Arias,et al.  A thermo-viscoplastic constitutive model for FCC metals with application to OFHC copper , 2010 .

[6]  E. Orowan,et al.  Problems of plastic gliding , 1940 .

[7]  S. S. Kang,et al.  Dynamic strain aging in SA508-class 3 pressure vessel steel , 1995 .

[8]  U. F. Kocks,et al.  A constitutive description of the deformation of copper based on the use of the mechanical threshold stress as an internal state variable , 1988 .

[9]  P. Hirsch.  Kear-Wilsdorf locks and the formation of antiphase-boundary tubes in L1 2 alloys , 2003 .

[10]  Jin-hui DU,et al.  Progress in the research and manufacture of GH4169 alloy , 2015 .

[11]  S. Nemat-Nasser,et al.  A model for experimentally-observed high-strain-rate dynamic strain aging in titanium , 2000 .

[12]  U. F. Kocks,et al.  The strain dependence of static and dynamic strain-aging , 1982 .

[13]  Weiguo Guo,et al.  Anomalous behaviors of a single-crystal Nickel-base superalloy over a wide range of temperatures and strain rates , 2016 .

[14]  P. Zhou,et al.  Modified Johnson-Cook description of wide temperature and strain rate measurements made on a nickel-base superalloy , 2017 .

[15]  Weiguo Guo,et al.  The influence of heat treatment and strain rate on the third type strain ageing phenomenon , 2019 .

[16]  I. Beyerlein,et al.  A crystal plasticity model incorporating the effects of precipitates in superalloys: Application to tensile, compressive, and cyclic deformation of Inconel 718 , 2017 .

[17]  Kangbo Yuan,et al.  Influence of process parameters and heat treatments on the microstructures and dynamic mechanical behaviors of Inconel 718 superalloy manufactured by laser metal deposition , 2018 .

[18]  Weixing Chen,et al.  On the mechanism of serrated deformation in aged Inconel 718 , 1997 .

[19]  G. Nicoletto,et al.  Microstructure and directional fatigue behavior of Inconel 718 produced by selective laser melting , 2016 .

[20]  R. B. Pęcherski,et al.  Analysis of thermo-visco-plastic behaviour of six high strength steels , 2009 .

[21]  Reinhart Poprawe,et al.  Improvement of material performance of Inconel 718 formed by high deposition-rate laser metal deposition , 2016 .

[22]  C. C. Li,et al.  Effects of dynamic strain aging on the subsequent mechanical properties of carbon steels , 1978 .

[23]  Shu Beng Tor,et al.  Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: A critical review , 2018 .

[24]  Amin H. Almasri,et al.  A physically based constitutive model for fcc metals with applications to dynamic hardness , 2008 .

[25]  U. Glatzel,et al.  Microstructure and mechanical properties of selective laser melted Inconel 718 compared to forging and casting , 2016 .

[26]  Sia Nemat-Nasser,et al.  Determination of temperature rise during high strain rate deformation , 1998 .

[27]  Weidong Huang,et al.  The effect of laser scanning path on microstructures and mechanical properties of laser solid formed nickel-base superalloy Inconel 718 , 2011 .

[28]  W. C. Hayes,et al.  On the mechanism of delayed discontinuous plastic flow in an age-hardened nickel alloy , 1982 .

[29]  M. Rodríguez-Millán,et al.  A dislocation-based constitutive description for modeling the behavior of FCC metals within wide ranges of strain rate and temperature , 2011 .

[30]  S. Nemat-Nasser,et al.  Thermomechanical response of HSLA-65 steel plates: experiments and modeling , 2005 .

[31]  M. Knezevic,et al.  Microstructure and mechanical behavior of direct metal laser sintered Inconel alloy 718 , 2016 .

[32]  R. Armstrong,et al.  Dislocation-mechanics-based constitutive relations for material dynamics calculations , 1987 .

[33]  S. Zwaag,et al.  A constitutive model for high strain rate deformation in FCC metals based on irreversible thermodynamics , 2009 .

[34]  Soon-Bok Lee,et al.  Modeling of materials behavior at various temperatures of hot isostatically pressed superalloys , 2012 .

[35]  R. Dehoff,et al.  Effect of anisotropy and texture on the low cycle fatigue behavior of Inconel 718 processed via electron beam melting , 2017 .

[36]  Xin Lin,et al.  The influence of Laves phases on the high-cycle fatigue behavior of laser additive manufactured Inconel 718 , 2017 .

[37]  Wei-guo Guo,et al.  On the constitutive modeling of a structural steel over a range of strain rates and temperatures , 2013 .

[38]  W. Johnston,et al.  Dislocation Velocities, Dislocation Densities, and Plastic Flow in Lithium Fluoride Crystals , 1959 .

[39]  Ryan B. Wicker,et al.  Fabrication of Metal and Alloy Components by Additive Manufacturing: Examples of 3D Materials Science , 2012 .

[40]  G. Nicoletto,et al.  Long fatigue crack growth in Inconel 718 produced by selective laser melting , 2016 .

[41]  Wei-guo Guo,et al.  The third-type of strain aging and the constitutive modeling of a Q235B steel over a wide range of temperatures and strain rates , 2015 .

[42]  Liangchi Zhang,et al.  Constitutive modelling of plasticity of fcc metals under extremely high strain rates , 2012 .

[43]  M. Colliander,et al.  Effect of microstructure on dynamic shear localisation in Alloy 718 , 2017 .

[44]  E. Chlebus,et al.  Fatigue crack growth rate and tensile strength of Re modified Inconel 718 produced by means of selective laser melting , 2017 .

[45]  C. G. Krishnadas Nair,et al.  Laser metal deposition repair applications for Inconel 718 alloy , 2017 .

[46]  P. Blackwell,et al.  The mechanical and microstructural characteristics of laser-deposited IN718 , 2005 .

[47]  R. Armstrong,et al.  The effect of dislocation drag on the stress-strain behavior of F.C.C. metals , 1992 .

[48]  S. Nemat-Nasser,et al.  Thermomechanical response of DH-36 structural steel over a wide range of strain rates and temperatures , 2003 .