Controlling shape, size, and surface roughness of aluminum cold plate fabricated via single-step sub-surface friction stir channeling for battery pack cooling

Abstract

The Battery Thermal Management System rely heavily on cold plates. Manufacturing cost effective, highly productive cold plates having integrated channels is promising solution for thermal management. Friction Stir Channeling is a newly developed and promising manufacturing process for the formation of integrated functional channels on metal blocks for cold plate applications. This research presents the solution to control over channel surface roughness, catering to thermal management system requirements, and shows that it is achievable by manipulating factors like heat input, plasticization effect, and process pitch (v/ω). The study establishes the correlations between important channel features and secondary parameters like pseudo heat index (PHI), flow stress (σ_f), and changes in thermal history. Notably, the study highlights the pivotal role of channel roughness as a key determinant of corrosion initiation within the channel through an electrochemical corrosion test. Additionally, the FSC process is found to impart lower compressive residual stresses adding to the advantages of the process.