Another key parameter that affects the coating deposition efficiency of coating technology is the contact angle. The particle tangential sliding on the substrate at impact is due to the supersonic gas flow bow shock which is responsible for the erosion at the surface of the substrate.  Several studies both in macro- and micro-scales are observed to examine a broad variety of impact phenomena. Examples of such phenomena are the ballistic impact, a macro body penetrating another body at supersonic velocity causing the impacted surface destruction and the particle erosion at a velocity relatively below the critical velocity with a metallic surface. In metallic particle erosion, the continuous impact of the erodent particles causes the detachment of the impacted material from the substrate surface due to the fracture and damage at the interfacial zone as the material fails.  However, at intermediate velocities ranging from 300 m/s to 1,200 m/s, metallic solid particles can form a coating after impacted the substrate surface at relatively low temperatures below the material melting point. This study presented a finite element approach of a numerical model to investigate the profile of the deformed sprayed particles under the condition of oblique impact and the erosion mechanism for solid particle impact on ductile material during Cold Gas Dynamic spray. Elastic, isotropic hardening, Johnson-Cook damage criteria and Dynamic failure model (i.e. tensile and shear failure models) were selected to account for elasticity, plasticity, stress softening behaviour of the ductile materials and material damage model as the material model formulations respectively. In the numerical modelling of cold gas dynamic spray (CGDS) by a Lagrangian approach that was developed, single and multiple erodent particles on the substrate at controlled contact angle (10^0^ -90^0^), velocity (400-600 m/s) and friction coefficient (0.1-0.5) was simulated. The result from the literature was used for model verification. It was discovered that in the substrate, the crater depth decreases as well as the area of contact between the substrate and the deformed particles when the contact angle increases at the same impacting conditions. The material removal and crack formation mechanism were also simulated successfully by the accumulation of residual strain that resulted in the dynamic detachment of material elements at the surface as they fail. During the crack’s propagation, four steps were discovered which includes the void formation, erosion and coalescence cracks caused by wear of erodent particles, crack growth, and coalescence of cavities which causes crack formation. It was also discovered that a decrease in contact angle, increase in the coefficient of friction and increase in impact velocity all contribute to an increase in erosion rate. This model can be used to study wear mechanisms and the prediction of the morphology of the eroded surfaces of the ductile material.


Numerical Modelling for Oblique Impacts With Ductile Material Particle Erosion During Cold Gas Dynamic Spray

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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