Role of In-Situ Dynamic Splat Sintering on Elastic and Damping Behavior of Cold Sprayed Aluminum Coatings

The dynamic elastic behavior of cold sprayed aluminum 6061 coatings is analyzed to understand the inherent role of in-situ splat sintering from ambient to 400 oC for air and helium sprayed coatings. Higher surface energy and lower flattening ratio of air sprayed coating in as-sprayed condition result in 28% densification during splat sintering compared to 15% in heat-treated helium sprayed ones. Elastic modulus and damping behavior can be divided into three distinct temperature regimes based on dynamic sintering and progressive intersplat structure. A theoretical analysis is established, which shows that normalized elastic modulus is an exponential function of the inter-splat porosity. This study establishes the correlation between inter-splat thermal phenomena and coating’s dynamic mechanical properties at elevated temperatures.