Physically Based Finite Element Modeling Method to Predict Metallic Bonding in Cold Spray

Abstract

The cold spray (CS) process is unique due to its high strain rate deformation and particle deposition in solid state. In situ investigation of this process is challenging. Therefore, numerical methods have been used to simulate this process and provide a better ground for furthering the understanding of the process physics. Metallurgical bonding occurs during the deformation process at the particle/substrate interface during coating build-up. Up to now, several studies have been performed to predict the material behavior during this process. Although several studies have been done to predict the bonding in CS, none of them was able to show the occurrence of localized metallurgical bonding. In this study, a novel modeling method is proposed to predict the occurrence and strength of localized metallurgical bonds in the CS process through finite element method. The process physics and implementation method are explained in details. Critical velocities of aluminum, copper, and nickel were predicted and compared with experimental data to validate the method. In addition, the proposed method is able to show the localized metallurgical bonding at the interface between particle and substrate. Comparison between the predicted bonding area with the proposed method and experimental data from the literature showed good agreement.

The Transition From Rebound to Bonding in High-Velocity Metallic Microparticle Impacts: Jetting-Associated Power-Law Divergence

“…The excess lost energy E d would then be associated with the energy of refracturing those metallic bonds. This view is in line with simulations contemplating the effects of temporary bonding on impact and rebound behavior [36]. Simplistically, we can estimate this debonding energy, E d (D) , as that dissipated in a mode I fracture event in a plane stress condition…”

A Novel Modeling Method to Study the Oxide Layer Effect on Metallic Bonding in Cold Gas Dynamic Spray Process

“…Understanding and predicting material behavior in high strain rate processes, such as cold spray (CS), has been a major endeavor for decades. CS process particularities (solid state deposition under high strain rates and low temperatures [1]) make it unique and more investigations are required for complete physical understanding. Investigations of material interactions at the substrate/coating interface during impact are still required to expand the process knowledge.…”

“…Investigations of material interactions at the substrate/coating interface during impact are still required to expand the process knowledge. Although several studies have examined substrate/coating interactions, none of them used a holistic approach to predict the occurrence of localized metallurgical bonding at the contact area [1].…”

“…Mechanical anchoring and metallurgical bonding are the main deposition mechanisms involved in the CS process [1]. In mechanical anchoring nano/micro length-scale physical mixing occurs and causes the particles to adhere physically to the substrate [1]. Metallurgical bonding involves the formation of atomic bonds (chemical bond) between the particle and the substrate.…”

“…Metallurgical bonding involves the formation of atomic bonds (chemical bond) between the particle and the substrate. This type of bonding requires that two oxide-free metallic surfaces be put into contact under a sufficiently high localized pressure [1]. The innate oxide film on the metallic surfaces must be broken to allow the free-oxide surfaces to be exposed [1].…”