A method for characterizing the quasi-static mechanical behavior of powders for the cold spray process

Abstract

Mechanical properties of the powder are a critical factor for solid-state processes based on powder consolidation, as the cold spray. We propose a method to determine the quasi-statical behavior of powders based on single particle microcompression. Finite elements numerical modeling of the microcompression test are used to train and validate a Kriging meta-model, on which is based a computationally efficient optimization process, allowing the identification of the parameters of the material behavior law chosen. The method has been applied to Al 1070 spherical particles, using a rate-independent Johnson-Cook material model, but can potentially be used for any material and any plasticity model. Results confirm the validity of the proposed method and highlight a marked heterogeneity of behavior among particles from the same powder batch. This is supported also by microstructural differences and can be related to inhomogeneities in the powder manufacturing process.