Abstract
In cold spray, bonding is created between a substrate and the
particles and between particles through impact deformation at
high strain rates. A prominent feature of the cold spray process
is the compressive residual stress that arises during the
deposition process. Compressive residual stress on the surface
can be beneficial for fatigue resistance. As a post processing
technique several applications require surface treatment
processes that produce this state of stress on component surfaces
such as shot peening, laser shock peening, ultrasonic impact
treatment, low plasticity burnishing, etc. In all of these methods
the compressive stress is produced through plastic deformation
of the surface region. In a similar manner, the cold spray process
induces compressive stress by high speed impact of the sprayed
particles on the surface, causing a peening effect. The effects of
these variations in the properties of the coatings are rarely
reported. Moreover there are some applications which require
minimal residual stresses in the components such as in optics. In
this study, we have investigated the residual stress using
numerical analysis of the multi-particle impact behavior in cold
spray.