First-Principle Calculation on Critical Velocity for Cu and Al Cold-Spray Bonding

The first-principles calculation with a newly developed high-efficient computing method was firstly applied to prediction of critical velocity for Cu/Al cold-spray bonding without any empirical parameters. An excellent agreement between predicted values and experimental values was obtained. The bonding mechanism of cold-spray was clarified by analyzing the atomic response in displacement during cold-spray process. A mixed bonding mechanism of adiabatic shear instability and pressure-release was confirmed. The computing method could be popularized to extensive applications in critical velocity prediction.