<Abstract>

The deposition mechanisms of metallic glass particles impacting a substrate

at high velocity (385–485 m/s) and temperatures near and above the glass

transition are studied using finite element modeling. The deformation mechanisms

of the metallic glass particles in these conditions are extremely dependent on their

Reynolds number only leading to deposition and bonding at high Reynolds number.

Unlike early works, this study includes the homogenous flow deformation under

Newtonian and non-Newtonian regime modeled using the constitutive equations

of the free-volume model. The computed results are compared against experimental

data of metallic glass coatings build-up by Cold Gas Spray. A critical value of the

Reynolds number is found by both experiments and simulation, showing that it is a

useful parameter to control the activation of viscoplastic deformation and bonding

of metallic glass particles. Interestingly, this work demonstrates that deposition of

metallic glass particles is governed by a cooperative movement of the liquid instead

of a simple shear instability effect at the particle-substrate interface unlike

polycrystalline metals.
<全文連結>