Enhancing capillary performance of aluminum alloy micro-grooved miniature heat pipes using a novel self-sealing hydrothermal process

Aluminum alloy micro-grooved miniature heat pipes offer significant advantages for dissipation of high heat flux densities in confined spaces within thermal management systems of electronic equipment in aerospace and other fields, owing to their high thermal conductivity, miniaturization, and lightweight properties. However, the insufficient capillary performance of the micro-grooved wicks in aluminum alloy miniature heat pipes has become a key factor limiting their heat transfer efficiency. This study addresses the enhancement of capillary performance in aluminum alloy heat pipes by proposing a self-sealing hydrothermal process (SSHP) to construct micro/nanostructures on the surfaces of micro-grooved heat pipes, thereby improving capillary performance. The study investigates the ways in which the SSHP process affects aluminum alloy surface wettability and the underlying mechanisms, analyzes the effects of SSHP process parameters on the capillary performance of aluminum alloy micro-grooved miniature heat pipes, and optimizes these parameters. The results demonstrate that SSHP treatment induces a superhydrophilic transformation on the aluminum alloy surface, strongly correlated with the shape characteristics of the constructed surface nanostructures. A smaller average aspect ratio and longer average length of boehmite nanostructures correlate with increased hydrophilicity of the aluminum alloy surface. Following SSHP treatment, the capillary performance of aluminum alloy micro-grooved heat pipes increases by up to 2679%. The mechanism behind this enhancement is elucidated, and optimal SSHP process parameters for aluminum alloy micro-grooved heat pipes are proposed. This study provides theoretical and technical support for the fabrication of high-capillary-performance aluminum alloy miniature heat pipes.