The effects of gas and metal characteristics on sprayed metal coatings

Abstract

Supersonic particle deposition (also known as cold spray) is a surface coating process whereby metal particles are accelerated to supersonic speeds while entrained in nozzle gas flow and are subsequently deposited by impact onto a surface. Particle velocity is critical for optimal deposition efficiency and coating quality, and several parameters, including gas conditions, particle characteristics and nozzle geometry affect particle velocity. This study investigates the relationship between particle velocity and coating quality and investigates how nozzle design influences particle velocity. Performance is described through modelling and verified by direct velocity measurements.

The use of kinetic metallization to form intermetallic reinforced composite coatings by post-spray heat treatment

“…For single element deposition, the efficiency may vary from 15% to greater than 90% [21,35,36] depending on the type of sprayed powder, the size of the particles, the gas pressure and temperature and the nozzle. The remainder of the powder rebounds from the substrate.…”

Carbon nanotube reinforced aluminum composite coating via cold spraying

“…The constitutive relations for plastic flow used in modeling the deformation and bonding take care of the dependence of the flow stress on the strain, strain rate, temperature and pressure. The parameters affecting the process and spraying efficiency are particle size, density of particles, temperature of gas, density of gas and spraying angle, and various models have been proposed for the effect of various parameters [4][5][6]. Cold spraying has been used to deposit many types of materials including pure metals [7][8][9][10][11], alloys [12][13][14][15] and composite materials [16][17][18][19].…”

High-Velocity Impact of Encased Al/PTFE Projectiles on Structural Aluminum Armor

“…The nickel-aluminum casing was fabricated with a cold-spray process. [4] An aluminum-nickel powder mixture using a 30/70 nickel/aluminum ratio was sprayed onto a mandrel until a sufficient thickness of material existed. The mandrel and the outside of the casing were then machined to create the final part.…”