Combined Laser Shock and Micro-Compression Approach to the Mechanical Behavior of Powders for Cold Spray

2021 ◽  
Author(s):  
H. Durand ◽  
L. Lacourt ◽  
J.-C. Teissedre ◽  
F. Delloro ◽  
A. Thorel ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Cold Spray ◽  
High Speed ◽  
Fem Simulation ◽  
Material Behavior ◽  
Laser Shock ◽  
High Speed Imaging ◽  
Spray Process ◽  
Before And After ◽  
Cook Model

Abstract In cold spray, particles undergo large plastic deformation upon impact in a rapid dynamic regime (up to 109 s-1) at solid state. The simulation of this impact is key to understanding the cold spray process. In this study, an approach based on laser shock and micro-compression testing was developed to characterize the mechanical behavior of powders and fit parameters of the Johnson-Cook material behavior model. In situ micro-compression particle testing was performed in a SEM equipped with a microindentation stage. From subsequent FEM simulations of the test, static coefficients of the Johnson-Cook model were identified. A laser shock powder launcher (LASHPOL) was also developed to accelerate single particles and measure their corresponding velocity using high-speed imaging. In addition, image analysis of the particles before and after impact, together with FEM simulation, were used to determine strain rate hardening coefficients for the Johnson-Cook model.

scholarly journals Microstructure, Mechanical Properties and Corrosion Behavior of the Aluminum Alloy Components Repaired by Cold Spray with Al-Based Powders

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1633
Author(s):  
Zhiyi Zhang ◽  
Xiaoguang Sun ◽  
Shiming Huang ◽  
Xiaohui Han ◽  
Ping Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Cold Spray ◽  
Corrosion Behavior ◽  
High Speed ◽  
Neutral Salt ◽  
Cold Spray Process ◽  
Spray Process ◽  
High Speed Trains ◽  
Mechanical Properties And Corrosion

Aluminum alloy components of high-speed trains have a great risk of being corroded by various corrosive medium due to extremely complex atmospheric environments. This will bring out huge losses and reduce the safety and stability of trains. In order to solve the problem, cold spray process was used for repairing the damage of the aluminum alloy components with Al-based powders. Microstructure, mechanical properties and corrosion behavior were studied. The results indicated that there were very few pores and cracks in the repaired areas after repairing. The average microhardness of the repaired areas was 54.5 HV ± 3.4 HV, and the tensile strength of the repaired samples was 160.4 MPa. After neutral salt spray tests for 1000 h, the rate of mass loss of the samples repaired by cold spray was lower than that of 6A01 aluminum alloy. The electrochemical test results showed that the repaired areas had a higher open circuit potential than 6A01 aluminum alloy. As a result, the repaired areas such as the anode protected its nearby substrate. The samples repaired by cold spray exhibited better corrosion than 6A01 aluminum alloy. Cold spray process and Al-based powders are applicable for repairing the aluminum alloy components of high-speed trains.

Multifunctional Bioceramic Composite Coatings Deposited by Cold Spray

2019 ◽  
Vol 813 ◽  
pp. 228-233
Author(s):  
Kiran G. Judd ◽  
Mala M. Sharma ◽  
Timothy J. Eden
Keyword(s):  
Cold Spray ◽  
Composite Coatings ◽  
Total Porosity ◽  
Substrate Material ◽  
The Novel ◽  
Composite Powders ◽  
Bioactive Coatings ◽  
Spray Process ◽  
Novel Approach ◽  
Before And After

Bioactive coatings have predominately been explored through plasma spray; but this technique has associated heat and melting of the feedstock materials thereby degrading the novel bioactive properties of hydroxyapatite (HA), as well as deteriorating the adhesion of the coating to the implant. The current study discusses a novel approach to producing biocompatible coatings that have been deposited at temperatures well below their melting point. The cold spray process was used to deposit 100 wt.% titanium (Ti) and composite powders with 80 wt% titanium (Ti) and 20 wt% hydroxyapatite (HA) onto Al6061, 316SS and Ti-6Al-4V substrates with the aim of achieving well-bonded homogeneous coatings; the effect of process parameters and substrate material was investigated. Preliminary results indicate the phase composition of the HA remained the same before and after synthesis of coating. Dense composite coatings were obtained with thicker coatings yielding the least amount of total porosity.

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.

Residual Stress Characterization From Numerical Analysis of the Multi-Particle Impact Behavior in Cold Spray

2017 ◽  
Author(s):  
Kando Hamiyanze Moonga ◽  
Tien-Chien Jen
Keyword(s):  
Residual Stress ◽  
Numerical Analysis ◽  
Compressive Stress ◽  
Cold Spray ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Impact Behavior ◽  
Particle Impact ◽  
Cold Spray Process ◽  
Spray Process

In cold spray, bonding forms between a substrate and the particles and between particles through impact deformation at high strain rates. A prominent feature of the cold spray process is the compressive residual stress that arises during the deposition process. Compressive residual stress on the surface can be beneficial for fatigue resistance. As a post processing technique several applications require surface treatment processes that produce this state of stress on component surfaces such as shot peening, laser shock peening, ultrasonic impact treatment, low plasticity burnishing, etc. In all of these methods, the compressive stress is produced through plastic deformation of the surface region. In a similar manner, the cold spray process induces compressive stress by high speed impact of the sprayed particles on the surface, causing a peening effect. The effects of these variations in the properties of the coatings are rarely reported. Moreover, there are some applications which require minimal residual stresses in the components such as in optics. In this study, we have investigated the residual stress using numerical analysis of the multi-particle impact behavior in cold spray.

Investigation of Cold Sprayed NiCoCrAlY Bond Coating

2009 ◽  
Vol 79-82 ◽  
pp. 863-866 ◽  
Author(s):  
Xiang Bo Li
Keyword(s):  
Cold Spray ◽  
High Speed ◽  
Cold Spraying ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Bond Coating ◽  
Spray Process ◽  
High Speed Impact ◽  
Helium Gas

In this paper, NiCoCrAlY coating was deposited by cold spraying with helium gas under the temperature of 500°C and pressure of 2.6 MPa. The microstructure of the coating was characterized through surface morphology and cross-sectional microstructure by scanning electron microscopy and X-ray diffraction analysis. The results showed that the coating is deposited through intensive plastic deformation of the spray particles by high-speed impact, and no oxygen phenomena discovered in the cold spray process. We also detected the micro-hardness using the Digital Vickers Microhardness Tester. Result revealed that a compact texture and high micro-hardness NiCoCrAlY coating can be obtained by cold spray.

scholarly journals Effects of Dislocation Density Evolution on Mechanical Behavior of OFHC Copper during High-Speed Machining

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2348 ◽  
Author(s):  
Hongguang Liu ◽  
Jun Zhang ◽  
Xiang Xu ◽  
Yutong Qi ◽  
Zhechao Liu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Mechanical Behavior ◽  
Microstructure Evolution ◽  
High Speed ◽  
High Strain ◽  
Material Behavior ◽  
Strain Rates ◽  
High Speed Machining ◽  
High Strain Rates ◽  
Cutting Speeds

This paper aims at investigating the change in material behavior induced by microstructure evolution during high-speed machining processes. Recently, high-speed machining has attracted quite a lot of interest from researchers due to its high efficiency and surface quality in machining large-scale components. However, the material behavior could change significantly at high-cutting speeds compared to the conventional cutting conditions, including their microstructure and t mechanical response. This is due to the basic physics of material at microscopic levels with high strain, high strain rates, and high temperatures. In this study, the dislocation density-related microstructure evolution process and mechanical behavior of OFHC (Oxygen-free high-conductivity) copper in high-speed machining with speeds ranging from 750 m/min to 3000 m/min are investigated. SEM (Scanning Electron Microscope) and advanced EBSD (Electron Backscattered Diffraction) techniques are used to obtain high-quality images of the microstructures and analyze the dislocation density and grain size evolution with different cutting speeds. Moreover, as material plasticity is induced by the motion of dislocations at micro-scales, a dislocation-density based (DDB) model is applied to predict strain-stress and microstructure information during the cutting process. The distributions of dislocation densities, both statistically stored dislocations (SSDs) and geometrically necessary dislocations (GNDs), are obtained through simulation and experimentation, respectively. The results show that the fluctuation in the cutting forces at high cutting speeds is induced by the specific evolution and distribution of the dislocation density under high strain-rates, and the periodical distribution of sub-surface and fracture behavior during chip separation, which are also found to be influenced by the evolution of the dislocation density.

scholarly journals Influence of the Constitutive Flow Law in FEM Simulation of the Radial Forging Process

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Olivier Pantalé ◽  
Babacar Gueye
Keyword(s):  
High Speed ◽  
Fem Simulation ◽  
Material Behavior ◽  
Constitutive Law ◽  
Radial Forging ◽  
Forming Process ◽  
Forging Process ◽  
Elastic Plastic ◽  
Radial Forging Process ◽  
Flow Law

Radial forging is a widely used forming process for manufacturing hollow products in transport industry. As the deformation of the workpiece, during the process, is a consequence of a large number of high-speed strokes, the Johnson-Cook constitutive law (taking into account the strain rate) seems to be well adapted for representing the material behavior even if the process is performed under cold conditions. But numerous contributions concerning radial forging analysis, in the literature, are based on a simple elastic-plastic formulation. As far as we know, this assumption has yet not been validated for the radial forging process. Because of the importance of the flow law in the effectiveness of the model, our purpose in this paper is to analyze the influence of the use of an elastic-viscoplastic formulation instead of an elastic-plastic one for modeling the cold radial forging process. In this paper we have selected two different laws for the simulations: the Johnson-Cook and the Ludwik ones, and we have compared the results in terms of forging force, product's thickness, strains, stresses, and CPU time. For the presented study we use an AISI 4140 steel, and we denote a fairly good agreement between the results obtained using both laws.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

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