A modified Johnson-Cook material model with strain gradient plasticity consideration for numerical simulation of cold spray process

2020 ◽  
Vol 397 ◽  
pp. 125981 ◽  
Author(s):  
Rohan Chakrabarty ◽  
Jun Song
Keyword(s):  
Numerical Simulation ◽  
Cold Spray ◽  
Strain Gradient ◽  
Material Model ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity ◽  
Cold Spray Process ◽  
Spray Process

scholarly journals РОЗРАХУНОК ТЕМПЕРАТУРНО-ШВИДКІСНИХ ПАРАМЕТРІВ ЧАСТИНОК ПРИ ХОЛОДНОМУ ГАЗОДИНАМІЧНОМУ НАПИЛЮВАННІ

2019 ◽  
pp. 139-144
Author(s):  
Олександр Володимирович Шорінов ◽  
Андрій Олегович Волков ◽  
Сергій Євгенійович Маркович ◽  
Анатолій Іванович Долматов
Keyword(s):  
Numerical Simulation ◽  
Critical Velocity ◽  
Cold Spray ◽  
Aluminum Powder ◽  
Cold Spray Process ◽  
One Dimensional ◽  
Spray Process ◽  
Gas Dynamic ◽  
Temperature And Pressure ◽  
Nozzle Inlet

The method of computational fluid dynamics (CFD) for the supersonic nozzle SK-20 of the low-pressure cold gas-dynamic spraying equipment DYMET-405 was applied for calculation of particles impact temperature and velocity. The application of the CFD method is the one-dimensional isentropic gas-dynamic model considers the flow only along the nozzle axis, without taking into account the heat exchange with the nozzle and the friction losses on the internal walls, which leads to obtaining overestimated results of calculations. Previously it was found out that the difference in the values obtained by numerical simulation and the results of calculations of a one-dimensional isentropic model was less than 10%. Numerical simulation of the two-phase flow of the cold spray process has been performed using the Ansys Fluent Academic software package. The influence of the initial cold spray process parameters such as temperature and pressure at the nozzle inlet on the change in temperature and velocity of aluminum particles with a diameter of 25 μm at the moment of impact with the substrate has been studied. Also, the influence of the particle size on the above-mentioned parameters has been obtained. The numerical simulation results of the particle impact temperature with the substrate have been used to calculate the critical velocity of aluminum powder – the velocity needed for coating formation. It is known that the formation of cold spray coatings depends on the velocity of the powder particles. For each material, there is a critical velocity at which the process of forming the coating begins. At particle velocities above the critical one, their adhesion to the substrate and the formation of the coating, due to the plastic deformation of the particles, occurs, while at lower velocities the surface erosion or deposition with low efficiency under certain conditions is observed. As a result of simulation and calculations of the critical velocity, the window of spraying was developed, that is the region of values of velocities and temperatures of the particles of aluminum powder, depending on the temperature and pressure of the air at the nozzle inlet, at which the formation of coatings is possible.

Strain Gradient Plasticity Modeling to Evaluate Material Plastic Deformation Behavior During Cold Gas Dynamic Spray Process

2021 ◽  
Author(s):  
D. Dzhurinskiy ◽  
S. Dautov ◽  
P. Shornikov ◽  
I. Sh. Akhatov
Keyword(s):  
Plastic Deformation ◽  
Strain Gradient ◽  
Thermodynamic Characteristics ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity ◽  
Particle Deformation ◽  
Spray Process ◽  
Plastic Deformation Behavior ◽  
Manufacturing Applications ◽  
Material Length Scale

Abstract Severe plastic deformation (SPD) is the main feature of the Cold Spray (CS) process; which might result in producing metal grain refinement under extensive hydrostatic pressure and high strain rate loading conditions. In this study; an anisotropic strain gradient plasticity model (SGP) is presented to predict materials behavior in CS process. The enhanced dislocation densities produced throughout particle deformation affect coating material properties and modify their thermodynamic characteristics and kinetic of resistance to plastic deformations. This study also demonstrates that the SGP model can describe the experimentally observed trends and account for homogenization of the accumulated strains under dynamic recrystallization conditions. The evolution of statistically stored dislocation density through the characteristic material length scale parameter is in good agreement with experimental results and data reported by other research groups. The proposed SGP modeling is suggested as an express method to evaluate the advanced coating and additively manufactured materials; and powder feedstock used in thermal spray and 3D manufacturing applications.

Residual stresses in single particle splat of metal cold spray process – Numerical simulation and direct measurement

2018 ◽  
Vol 230 ◽  
pp. 152-156 ◽  
Author(s):  
Xu Song ◽  
Joris Everaerts ◽  
Wei Zhai ◽  
Han Zheng ◽  
Adrian Wei Yee Tan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stresses ◽  
Direct Measurement ◽  
Cold Spray ◽  
Single Particle ◽  
Cold Spray Process ◽  
Spray Process

scholarly journals AN ANALYTIC SOLUTION FOR ONE-DIMENSIONAL DISSIPATIONAL STRAIN-GRADIENT PLASTICITY

2009 ◽  
Vol 50 (3) ◽  
pp. 407-420
Author(s):  
ROGER YOUNG
Keyword(s):  
Boundary Condition ◽  
Strain Gradient ◽  
Analytic Solution ◽  
Strain Gradient Plasticity ◽  
Numerical Results ◽  
Gradient Plasticity ◽  
One Dimensional ◽  
Numerical Result ◽  
Formulation Analysis ◽  
The One

AbstractAn analytic solution is developed for the one-dimensional dissipational slip gradient equation first described by Gurtin [“On the plasticity of single crystals: free energy, microforces, plastic strain-gradients”, J. Mech. Phys. Solids48 (2000) 989–1036] and then investigated numerically by Anand et al. [“A one-dimensional theory of strain-gradient plasticity: formulation, analysis, numerical results”, J. Mech. Phys. Solids53 (2005) 1798–1826]. However we find that the analytic solution is incompatible with the zero-sliprate boundary condition (“clamped boundary condition”) postulated by these authors, and is in fact excluded by the theory. As a consequence the analytic solution agrees with the numerical results except near the boundary. The equation also admits a series of higher mode solutions where the numerical result corresponds to (a particular case of) the fundamental mode. Anand et al. also established that the one-dimensional dissipational gradients strengthen the material, but this proposition only holds if zero-sliprate boundary conditions can be imposed, which we have shown cannot be done. Hence the possibility remains open that dissipational gradient weakening may also occur.

A Study of Microindentation Hardness Tests by Mechanism-based Strain Gradient Plasticity

2000 ◽  
Vol 15 (8) ◽  
pp. 1786-1796 ◽  
Author(s):  
Y. Huang ◽  
Z. Xue ◽  
H. Gao ◽  
W. D. Nix ◽  
Z. C. Xia
Keyword(s):  
Strain Gradient ◽  
Size Dependence ◽  
Plasticity Theory ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity ◽  
Hierarchical Framework ◽  
Microindentation Hardness ◽  
Dislocation Hardening ◽  
Hardness Tests ◽  
Micro Indentation

We recently proposed a theory of mechanism-based strain gradient (MSG) plasticity to account for the size dependence of plastic deformation at micron- and submicronlength scales. The MSG plasticity theory connects micron-scale plasticity to dislocation theories via a multiscale, hierarchical framework linking Taylor's dislocation hardening model to strain gradient plasticity. Here we show that the theory of MSG plasticity, when used to study micro-indentation, indeed reproduces the linear dependence observed in experiments, thus providing an important self-consistent check of the theory. The effects of pileup, sink-in, and the radius of indenter tip have been taken into account in the indentation model. In accomplishing this objective, we have generalized the MSG plasticity theory to include the elastic deformation in the hierarchical framework.

scholarly journals SPH modeling of adhesion in fast dynamics: Application to the Cold Spray process

2016 ◽  
Vol 344 (4-5) ◽  
pp. 211-224 ◽  
Author(s):  
Paul Profizi ◽  
Alain Combescure ◽  
Kahuziro Ogawa
Keyword(s):  
Cold Spray ◽  
Cold Spray Process ◽  
Spray Process
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