scholarly journals A Parametric Simulation Model for HVOF Coating Thickness Control

2021 ◽  
Author(s):  
Jiangzhuo Ren ◽  
Rafiq Ahmad ◽  
Guofeng Zhang ◽  
Yiming Rong ◽  
Yongsheng Ma
Keyword(s):  
Numerical Model ◽  
Coating Thickness ◽  
Particle Deposition ◽  
Substrate Surface ◽  
Thickness Distribution ◽  
Gaussian Model ◽  
Thermal Spraying ◽  
Mathematical Expression ◽  
Circular Pattern ◽  
Combustion Flame

Abstract High velocity oxygen-fuel (HVOF) thermal spraying is a coating process involving multidisciplinary aspects, e.g., the fuel-oxidant combustion, flame-particle jet, particle deposition, mass and heat transfer, and even robotic kinematics. Like most coating processes, in HVOF processes, coating thickness is a significant property determining the coating performance, hence this property should be accurately controlled during the process. In view of green, smart, and digital manufacturing, the coating thickness prediction model is demanded for producing high-quality coatings efficiently. This paper presents an approach to parametrically simulate the coating thickness in HVOF processes via an integrated numerical model. Firstly, an axisymmetric computational fluid dynamics (CFD) model is constructed to compute the behaviors of the fuel-oxidant combustion, flame-particle jet, and particle deposition distribution. Secondly, based on the particle distribution in a 2D axisymmetric model, a 3D single coating thickness profile model is developed by constructing a circular pattern using the axis of the nozzle. Further, this profile is smoothened by a Gaussian model and its mathematical expression is obtained. Finally, a numerical model couples spray paths with the mathematical expression to model the coating thickness distribution on a substrate surface under industrial scenarios. At the end of this paper, the coating results of four sets of operating parameters were experimentally obtained and compared with the predicted simulation results to verify the proposed model’s effectiveness.

A Numerical Model for Simulating Liquid Particles Deposition on Surface

2018 ◽  
Author(s):  
Zhenxia Liu ◽  
Fei Zhang ◽  
Zhengang Liu
Keyword(s):  
Particle Size ◽  
Numerical Model ◽  
Particle Deposition ◽  
Surface Profile ◽  
Leading Edge ◽  
Solid Particles ◽  
Liquid Particle ◽  
Aircraft Icing ◽  
Turbine Vane ◽  
Deposition Thickness

The deposition of liquid particles, which may be converted from solid particles due to high temperature gas heating, makes much more harm on turbine vane blades compared to solid particles, since it may block film-cooling holes, worsen the cooling efficiency and aerodynamic performance of the turbine vane blades. Due to the similarity between the deposition of liquid particles on a surface and the icing on a surface, a numerical model for simulating particles deposition was developed based on the Myers icing model, an extension of the Messinger model, which has been applied in predicting aircraft icing or aero-engine icing. Compared to the conventional liquid particle deposition model, the numerical model in this paper considers the heat transfer and the flow of liquid particles during the particles phase transition from liquid state to solid state. In this model, the change of the surface profile due to the particles deposition was also considered, which was implemented with dynamic mesh technique. To test this model, deposition distribution and thickness obtained from the numerical simulations were compared to the experimental results. Additionally, a numerical simulation was conducted for liquid particle deposition on a flat plate. The result showed that the deposition thickness at the leading edge was much larger than that on the upper surface where the deposition appeared mainly at the middle and rear of the plate. The deposition mass and thickness increased with the increasing in the particle size. The effect of the particle size on the deposition thickness was more notable on the upper surface compared to that at the leading edge.

scholarly journals A review on the application of the theory of critical distance towards concrete

2018 ◽  
Vol 250 ◽  
pp. 03001 ◽  
Author(s):  
Mohamad Shazwan Ahmad Shah ◽  
Norhazilan Noor ◽  
Ahmad Beng Hong Kueh ◽  
Mohd. Nasir Tamin
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Mathematical Expression ◽  
Concrete Specimen ◽  
Critical Distance ◽  
Optimum Level ◽  
Additional Element ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Fracture Assessment

Theory of Critical Distance (TCD) is one of Fracture Mechanics numerical model that has gone through tremendous laboratory works and validation. Hence, it has been proven to be precise in broad perspectives in the field. Recently, TCD research related to fracture, especially fatigue on concrete are growing but the depth of study is still shallow and deficient compared to metal and steel. Thus, this made the fracture assessment in concrete obscures and governs by uncertainties. Previous efforts have managed to optimize TCD but the results only valid if the water-cement ratio of a concrete specimen in its optimum level. When the water-cement ratio is adjusted to a higher or lower from its optimum level, the output errors showed inconsistency as reported by Luca Susmel (2016). Therefore, this research aims to optimize the Theory of Critical Distance (TCD) by incorporating water-cement ratio and the interaction of microstructure matrix. The optimization involves few stages and finite element. If Theory of Critical Distance (TCD) can be improved by considering concrete’s additional element in its mathematical expression, it will definitely contribute to betterment in assessing concrete infrastructure around the globe.

Numerical Modeling of Piston Lubrication with Body Deformation through Modal Reduction Method

2017 ◽  
Vol 739 ◽  
pp. 193-201
Author(s):  
Seong Su Kim ◽  
Juh Wan Choi ◽  
Sung Soo Rhim ◽  
Jin Hwan Choi
Keyword(s):  
Numerical Model ◽  
Reduction Method ◽  
Thickness Distribution ◽  
Thickness Variation ◽  
Lubrication System ◽  
Operating Characteristics ◽  
Film Pressure ◽  
Oil Film ◽  
Modal Reduction ◽  
Oil Film Pressure

An analysis for operating characteristics of piston lubrication system is performed based on the numerical model in this study. Dynamic piston lubrication characteristics such as oil film pressure and thickness distribution can be analyzed through a numerical model with an integration of elastohydrodynamics and multi-flexible-body dynamics (MFBD). In particular, the oil film thickness variation by elastic deformation is considered in the elastohydrodynamic analysis by using the modal reduction method in MFBD system. And this effect is reflected on the fluid governing equations to evaluate the oil film pressure in the lubrication region. A series of process proposed in this study is available for the analysis of realistic elastohydrodynamic lubrication phenomenon. A numerical example for the piston lubrication system is also demonstrated.

Study on the Forming Process of the Crossmember in Car Intermediate Floor

2013 ◽  
Vol 442 ◽  
pp. 593-598
Author(s):  
Xue Xia Wang ◽  
Peng Chong Guan ◽  
Hai Peng Li ◽  
Li Hui Wang ◽  
Na Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Process Parameters ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Simulation Technology ◽  
Forming Process ◽  
Distribution Diagram ◽  
Simulation Results

Flanging and bending forming processes of the crossmember in car intermediate floor are investigated respectively by using numerical simulation technology. The numerical model of the crossmember was established and its press forming effect was simulated to determine the feasible process parameters affecting its manufacturability. Forming limit diagram and thickness distribution diagram are used to evaluate simulation results of different process schemes. And then optimum values of process parameters for flanging and bending are found, which can reduce the tendencies of wrinkling, springback and crackling during the stamping of the product.

Improvement of plating uniformity for copper patterns of IC substrate with multi-physics coupling simulation

Circuit World ◽  
2018 ◽  
Vol 44 (3) ◽  
pp. 150-160 ◽  
Author(s):  
Jing Xiang ◽  
Yuanming Chen ◽  
Shouxu Wang ◽  
Chong Wang ◽  
Wei He ◽  
...  
Keyword(s):  
Numerical Model ◽  
Current Distribution ◽  
Design Methodology ◽  
Thickness Distribution ◽  
Practical Application ◽  
Pattern Design ◽  
Environment Friendly ◽  
Content Type ◽  
Varied Pattern ◽  
Multiphysics Coupling

Purpose Optimized plating conditions, included proper designs of insulating shield (IS), auxiliary cathode (AC) and different patterns, contribute to the uniformity enhancement of copper deposition. Design/methodology/approach Plating experiments were implemented in vertical continuous plating (VCP) line for manufacturing in different conditions. Multiphysics coupling simulation was brought to investigate and predict the plating uniformity improvement of copper pattern. In addition, the numerical model was based on VCP to approach the practical application. Findings With disproportionate current distribution, different plating pattern design formed diverse copper thickness distribution (CTD). IS and AC improved plating uniformity of copper pattern because of current redistribution. Moreover, optimized plating condition for effectively depositing more uniformed plating copper layer in varied pattern designs were derived by simulation and verified by plating experiment. Originality/value The comparison between experiment and simulation revealed that multiphysics coupling is an efficient, reliable and of course environment-friendly tool to perform research on the uniformity of pattern plating in manufacturing.

Investigation on Residual Stress Development During Multiple Impacts in Cold Spray Process

2019 ◽  
Author(s):  
Sagil James ◽  
Karan Shah
Keyword(s):  
Cold Spray ◽  
Particle Deposition ◽  
Md Simulation ◽  
Substrate Surface ◽  
Spray Coating ◽  
Layer By Layer ◽  
Original Material ◽  
Cold Spray Process ◽  
Spray Process ◽  
The Impact

Abstract The Cold Spray Process (CS) is a solid-state particle deposition process. Unlike thermal spray coating methods, the CS process does not involve melting of the particles and thus retains the desired original material properties along with oxide-free deposition. As the technology is of dynamic nature with high-velocity particle impacts, the bonding mechanism involved is hugely complicated to understand. Even though the CS process offers great benefits, its potential applications are restrained by a lack of knowledge of the complex operations involved. Preliminary research which used molecular dynamics (MD) simulation of the CS process revealed that factors including the angle of impact, size of particle and impact velocity significantly affect the material deposition. However, the preliminary study only considered a single particle impact during the coating process. The CS process involves the impact of multiple particles on the substrate surface depositing layer-by-layer. This research focuses on investigating the residual stresses distribution caused by the impact of multiple nanoparticles on the substrate surface during the CS process using MD simulation technique. The results obtained by this study are instrumental in further advancing the applications of the CS processes.

Comparison Between the Numerical and Experimental Deposition Patterns for an Electrostatic Rotary Bell Sprayer

2015 ◽  
Author(s):  
Husam Osman ◽  
Kazimierz Adamiak ◽  
G. S. Peter Castle ◽  
Hua-Tzu (Charles) Fan ◽  
Joseph Simmer
Keyword(s):  
Numerical Model ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Particle Deposition ◽  
Numerical Results ◽  
Deposition Patterns ◽  
Dispersed Particles ◽  
3D Numerical Model ◽  
Deposition Thickness ◽  
Fractional Mass

In this paper, a full 3D numerical model using ANSYS commercial software has been created to simulate the particle deposition profile for stationary and moving flat targets, assuming multiple injections of charged poly-dispersed particles. Different injection angles along three virtual rings were assumed to form a shower injection pattern. The experimental and the numerical results of deposition thickness have been presented and compared for different injection patterns. It has been found that there are some parameters, such as the total number of injection points, the radii of the rings and the fractional mass flow rate in each injection ring, which affect the numerical results of the deposition thickness and uniformity.

scholarly journals Geopolymer: A Review on Physical Properties of Inorganic Aluminosilicate Coating Materials

2014 ◽  
Vol 803 ◽  
pp. 367-373 ◽  
Author(s):  
Mazlan Norkhairunnisa ◽  
M.N. Muhammad Fariz
Keyword(s):  
Coating Thickness ◽  
Interfacial Adhesion ◽  
Surface Effect ◽  
Substrate Surface ◽  
Chemical Properties ◽  
Cost Effective ◽  
Coating Materials ◽  
Geopolymer Matrix ◽  
Capacity Performance ◽  
Aluminosilicate Coating

Geopolymer is a potential material that can be used in many forms of applications such as for building, automotive, aerospace, and many more. It exhibits many excellent physical, thermal and chemical properties. Geopolymer material provides a cost effective and sustainable solution by recycle the hazardous residue material and it undergone green chemistry technique treatment. Geopolymerization process involves combination mixture of aluminosilicate from natural mineral or industrial waste such as fly ash or slag or rice husk ash with activated alkaline solution. This review paper exclusively explore more on the interfacial adhesion of geopolymer coating on substrate surface, effect of coating thickness and filler inclusion in geopolymer matrix system. Literature demonstrates that type of substrate and substrate surface plays a crucial role for good interfacial adhesion with geopolymer materials. In addition, coating thickness will affect the insulating capacity performance, while inclusion of filler can reduce the coating shrinkage problem.

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