Thermal design of hybrid materials produced via ultrasonic additive manufacturing

Ultrasonic additive manufacturing (UAM) is a technique for producing three-dimensional components through the metallurgical bonding of successive layers of metal foil. Due to its ability to process at low temperatures, UAM is uniquely suited for building hybrid materials. In this study, AA6061+water hybrid blocks with varying water cavity sizes were produced and their thermal performances were measured. Nonoptimal processing parameters were used to understand the interaction between interlayer porosity and thermal diffusivity of bulk material containing both solid and liquid. Flash thermography was used to characterize the spatial distribution of thermal diffusivity for each part. The average thermal diffusivity was successfully compared to a simplified thermal resistor model. The spatial variation in thermal properties was also correlated to specific interlayer features and related back to interactions between process characteristics and the component geometry.