A Numerical Investigation Into Cold Spray Bonding Processes

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Baran Yildirim ◽  
Hirotaka Fukanuma ◽  
Teiichi Ando ◽  
Andrew Gouldstone ◽  
Sinan Müftü
Keyword(s):  
Critical Velocity ◽  
Impact Velocity ◽  
Cold Spray ◽  
Cohesive Strength ◽  
Interfacial Bonding ◽  
Bonding Energy ◽  
Strength Parameter ◽  
Particle Impact ◽  
Particle Bonding ◽  
The Impact

Specific mechanisms underlying the critical velocity in cold gas particle spray applications are still being discussed, mainly due to limited access to in situ experimental observation and the complexity of modeling the particle impact process. In this work, particle bonding in the cold spray (CS) process was investigated by the finite element (FE) method. An effective interfacial cohesive strength parameter was defined in the particle–substrate contact regions. Impact of four different metals was simulated, using a range of impact velocities and varying the effective cohesive strength values. Deformation patterns of the particle and the substrate were characterized. It was shown that the use of interfacial cohesive strength leads to a critical particle impact velocity that demarcates a boundary between rebounding and bonding type responses of the system. Such critical bonding velocities were predicted for different interfacial cohesive strength values, suggesting that the bonding strength in particle–substrate interfaces could span a range that depends on the surface conditions of the particle and the substrate. It was also predicted that the quality of the particle bonding could be increased if the impact velocity exceeds the critical velocity. A method to predict a lower bound for the interfacial bonding energy was also presented. It was shown that the interfacial bonding energy for the different materials considered would have to be at least on the order of 10–60 J/m2 for cohesion to take place. The general methodology presented in this work can be extended to investigate various materials and impact conditions.

Effect of Particle Impact Velocity on Cone Crack Shape in Ceramic Material

2005 ◽  
Vol 297-300 ◽  
pp. 1321-1326 ◽  
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin
Keyword(s):  
Impact Velocity ◽  
Computational Simulation ◽  
Back Surface ◽  
Particle Impact ◽  
Cone Crack ◽  
Crack Shape ◽  
The Impact ◽  
Particle Impact Velocity ◽  
Sic Particle ◽  
Ring Cracks

The damage behaviors induced in a SiC by a spherical particle impact having a different material and size were investigated. Especially, the influence of the impact velocity of a particle on the cone crack shape developed was mainly discussed. The damage induced by a particle impact was different depending on the material and the size of a particle. The ring cracks on the surface of the specimen were multiplied by increasing the impact velocity of a particle. The steel particle impact produced the larger ring cracks than that of the SiC particle. In the case of the high velocity impact of the SiC particle, the radial cracks were generated due to the inelastic deformation at the impact site. In the case of the larger particle impact, the morphology of the damages developed were similar to the case of the smaller particle one, but a percussion cone was formed from the back surface of the specimen when the impact velocity exceeded a critical value. The zenithal angle of the cone cracks developed into the SiC decreased monotonically as the particle impact velocity increased. The size and material of a particle influenced more or less on the extent of the cone crack shape. An empirical equation was obtained as a function of impact velocity of the particle, based on the quasi-static zenithal angle of the cone crack. This equation will be helpful to the computational simulation of the residual strength in ceramic components damaged by the particle impact.

scholarly journals Экспериментальное и теоретическое исследование высокоскоростного проникания длинных стержневых ударников в песок

2022 ◽  
Vol 92 (3) ◽  
pp. 392
Author(s):  
С.И. Герасимов ◽  
Ю.Ф. Травов ◽  
А.Г. Иоилев ◽  
В.В. Писецкий ◽  
Н.Н. Травова ◽  
...  
Keyword(s):  
Experimental Data ◽  
Critical Velocity ◽  
Impact Velocity ◽  
Material Properties ◽  
Tungsten Heavy Alloy ◽  
30Khgsa Steel ◽  
Long Rod ◽  
The Impact ◽  
Hardening Coefficient ◽  
Penetration Coefficient

Results of computations with the use of improved modified Alekseevskii-Tate theory (IMATT) are compared to experimental data on high-velocity penetration of long rod projectiles into sand in the impact velocity range of V0=0.5-3.5 km/s. Projectiles were made of three different metals: M1 copper, WNZh tungsten heavy alloy and 30KhGSA steel. The value of hardening coefficient k in the linear dependence of the projectile material yield on pressure could be determined using IMATT and experimental data on dependence of differential penetration coefficient K on the penetration velocity. At penetration in regime of the hydrodynamic erosion of projectile, differential penetration coefficient K could be approximated just by dependence on the ratio of the impact velocity of penetration to the value of the critical velocity, above which the projectile deforms plastically during penetration. The values of the critical velocity may differ for specific projectile material properties as well as the density and the humidity of sand.

On Simulation of Multi-Particle Impact Interactions in the Cold Spray Process

2012 ◽  
Author(s):  
Baran Yıldırım ◽  
Andrew Hulton ◽  
Seyed Ali Alavian ◽  
Teiichi Ando ◽  
Andrew Gouldstone ◽  
...  
Keyword(s):  
Cold Spray ◽  
Failure Criteria ◽  
Material Behavior ◽  
Impact Behavior ◽  
Strength Parameter ◽  
Cold Spray Process ◽  
Spray Process ◽  
Method Effects ◽  
Cohesion Degree ◽  
The Impact

The cold spray process consists of coating build-up by sequential impact, deformation and bonding of many particles. Therefore, formation and properties of a deposited layer are not only affected by the impact behavior of a single particle, but also by subsequent impact events. To investigate the material behavior under such conditions, impact of multiple particles in cold spray was studied here by the finite element method. Effects of high strain rates and temperature on material yield and failure criteria were considered. Particle conditions prior to impact were derived from fluid dynamics calculations. To predict sticking behavior of the particle, an interfacial cohesive strength parameter was defined between the particle and the substrate. The effects of temperature and particle positioning were examined for three particle impacts. In addition, simulations involving 100 consecutive particle impacts were carried out, and findings were compared with experimental observations. Results showed that subsequent impacts have a large effect on the previously impacted particles for cohesion, degree of deformation, and residual stresses.

scholarly journals Study on performance degradation and damage modes of thin-film photovoltaic cell subjected to particle impact

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kailu Xiao ◽  
Xianqian Wu ◽  
Xuan Song ◽  
Jianhua Yuan ◽  
Wenyu Bai ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Conversion Efficiency ◽  
Photovoltaic Cell ◽  
Performance Degradation ◽  
Particle Impact ◽  
Laser Shock ◽  
Number Density ◽  
Mechanical Modeling ◽  
The Impact ◽  
Impact Experiments

AbstractIt has been a key issue for photovoltaic (PV) cells to survive under mechanical impacts by tiny dust. In this paper, the performance degradation and the damage behavior of PV cells subjected to massive dust impact are investigated using laser-shock driven particle impact experiments and mechanical modeling. The results show that the light-electricity conversion efficiency of the PV cells decreases with increasing the impact velocity and the particles’ number density. It drops from 26.7 to 3.9% with increasing the impact velocity from 40 to 185 m/s and the particles’ number densities from 35 to 150/mm2, showing a reduction up to 85.7% when being compared with the intact ones with the light-electricity conversion efficiency of 27.2%. A damage-induced conversion efficiency degradation (DCED) model is developed and validated by experiments, providing an effective method in predicting the performance degradation of PV cells under various dust impact conditions. Moreover, three damage modes, including damaged conducting grid lines, fractured PV cell surfaces, and the bending effects after impact are observed, and the corresponding strength of each mode is quantified by different mechanical theories.

Three Dimensional Numerical Simulation of Particle Deposition in Cold Gas Dynamic Spray Process

2016 ◽  
Author(s):  
Tien-Chien Jen ◽  
Yen-Ting Pan ◽  
Lin Zhu ◽  
Qinghua Chen
Keyword(s):  
Numerical Analysis ◽  
Critical Velocity ◽  
Three Dimensional ◽  
Bonding Process ◽  
Particle Impact ◽  
Gas Dynamic ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
The Impact ◽  
Cold Gas

Cold gas dynamics spraying (CGDS) is a process employing aerodynamics particle acceleration and high-speed impact dynamics surface-coating technology. The main advantages of CGDS include : (1) A low level of residual stresses; (2) CGDS can collect and reuse the undeposited particle more efficient than thermal spray processes; (3) Coatings can be deposited on materials that are temperature-sensitive; (4) Thick coatings can be produced to allow for free-standing structures or for rapid prototyping; (5) CGDS is safer because it is operated in low temperatures and low noise levels (6) Easy implementation due to its simplicity of technical design; (7). CGDS could produce high thermal and electrical conductivity of coatings. In the CGDS process, a high-pressure gas stream (generally 20–30 atm) carries metal particles (usually 1–50 μm in diameter) through a DeLaval type nozzle to reach a supersonic velocity before impact on the substrate. Typically, the impact velocities in the CGDS process range from 300 to 1200 m/s. When the particle exceeds the minimum deposition speed, adiabatic shear instabilities occur. This minimum deposition speed is also called critical velocity. In this paper, single particle impact simulations were performed to investigate the critical velocities of different particle sizes on the bonding process. This paper presents a three-dimensional numerical analysis of the particle critical velocity on the bonding efficiency in Cold Gas Dynamic Spray (CGDS) process by using ABAQUS/CAE 6.9-EF1. The particle impact temperature in CGDS is one of the most important factors that can determine the properties of the bonding strength to the substrate. In the CGDS process, bonding occurs when the impact velocity of particles exceed a critical velocity, which can reach minimum interface temperature of 60% of melting temperature in °C. The critical velocity depends not only on the particle size, but also the particle material. Therefore, critical velocity should have a strong effect on the coating quality. In the present numerical analysis, impact velocities were increased in steps of 100 m/s from the lowest simulated impact velocity of 300 m/s. This study illustrates the substrate deformations and the transient impact temperature distribution between particle(s) and substrate. In this paper, an explicit numerical scheme was used to investigate the critical velocity of different sizes of particle during the bonding process. Finally, the computed results are compared with the experimental data. Copper particles (Cu) and Aluminum substrate (Al) were chosen as the materials of simulation.

Influence of Confinement Condition on Particle Impact Damage in Soda-Lime Glass

2005 ◽  
Vol 297-300 ◽  
pp. 1315-1320
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin ◽  
Chang Min Suh
Keyword(s):  
Contact Pressure ◽  
Impact Velocity ◽  
Impact Damage ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Particle Impact ◽  
Glass Specimen ◽  
Radial Cracks ◽  
The Impact ◽  
Confinement Condition

In order to investigate the effect of a confinement condition on the damage induced by a spherical impact, an experimental setup that can impact contact pressure to the specimen through a pressing die was composed. The steel and the WC balls in 3mm diameter impacted to the soda-lime glass specimen with dimension of 33×33×8m in the impact velocity range of 30m/s to 200m/s. Three different conditions are given for the impact damage investigation, which are the case without a pressing die and the cases of p=0MPa and p=200MPa with a pressing die. The stress distribution in the glass specimen by impacting the particle was also evaluated using MARC s/w system. The particle impact produced various kinds of the damage such as the ring and the cone cracks, the radial cracks and the craters. The contact pressure applied to the specimen changed stress fields in the specimen. The damage zones of the specimen without a pressing die increased as the impact velocity increased. The damage extents in the specimen with the contact pressure of 200MPa were reduced as compared with the case of those without a pressing die.

On Cohesion of Micron Scale Metal Particles in High Velocity Impact With a Metal Substrate

2011 ◽  
Author(s):  
Baran Yildirim ◽  
Sinan Mu¨ftu¨ ◽  
Andrew Gouldstone
Keyword(s):  
High Strain ◽  
Copper Particle ◽  
Cohesive Strength ◽  
Strength Parameter ◽  
Strain Rates ◽  
Particle Deformation ◽  
Large Area ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
The Impact

Impact of a single copper particle in cold gas dynamic spray is simulated by finite element method by including the effects of high strain rates and temperature on material plasticity and failure. In order to predict stick behavior of the particle, cohesive forces that act between the particle and the substrate are included in the model by defining an interfacial cohesive strength parameter. Effect of this parameter on the deformation and stick/rebound behavior of the particle is studied. It is found that significant particle deformation, large area of contact between particle and substrate is needed to generate enough cohesive force to absorb the rebound energy of the particle and achieve sticking. As the impact velocity and assumed interfacial cohesive strength increases, particle is more likely to stick on to the substrate. Critical velocities in the same range with experimental results are predicted.

Thermal Analysis of the Particle Critical Velocity on Bonding Efficiency in Cold Gas Dynamics Spray Process

2010 ◽  
Author(s):  
Tien-Chien Jen ◽  
Sung-Cheng Wong ◽  
Yi-Hsin Yen ◽  
Qinghua Chen ◽  
Quan Liao
Keyword(s):  
Numerical Analysis ◽  
Critical Velocity ◽  
Impact Velocity ◽  
Interface Temperature ◽  
Copper Particles ◽  
Spray Process ◽  
Cold Gas Dynamic Spray ◽  
Gas Dynamic Spray ◽  
The Impact ◽  
Cold Gas

This paper presents a numerical analysis of the particle critical velocity on the bonding efficiency in Cold Gas Dynamic Spray (CGDS) process by using ABAQUS/CAE 6.9-EF1. The particle impact temperature in CGDS is one of the most important factors that can determine the properties of the bonding strength to the substrate. In the CGDS process, bonding occurs when the impact velocity of particles exceed a critical velocity [1], which can reach minimum interface temperature of 60% of melting temperature in °C [2]. The critical velocity depends not only on the particle size, but also the particle material. Therefore, critical velocity should have a strong effect on the coating quality. In the present numerical analysis, impact velocities were increased in steps of 100 m/s from the lowest simulated impact velocity of 300 m/s. This study illustrates the substrate deformations and the transient impact temperature distribution between particle(s) and substrate. In this paper, an explicit numerical scheme was used to investigate the critical velocity of different sizes of particle during the bonding process. Finally, the computed results are compared with the experimental data. Copper particles (Cu) and Aluminum substrate (Al) were chosen as the materials of simulation.

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