Stabilized metal nanowires with nanotwin boundaries used for boiling heat transfer

The poor structural thermal stability of metal micro-nanostructured surfaces significantly reduces their durability and stability in enhancing boiling heat transfer, rendering them unsuitable for use in the engineering of phase change heat dissipation devices. In this study, nanograins with twin boundaries, which possess lower grain boundary energy and can effectively suppress the grain coarsening phenomenon, were successfully induced for the first time in nanowires to enhance boiling heat transfer. Long-term boiling tests, multiple start-stop boiling cycles, and multiple heat flux overload experiments demonstrated that the lower interface enthalpy of twin-structured nanowires effectively suppressed the issue of grain coarsening commonly found in polycrystalline nanowires. Polycrystalline nanowires experienced significant coarsening, leading to the formation of micro-hills, which raised the surface superheat by 5.8 K at a heat flux of 150 W/cm 2 . On the contrary, twin-structured nanowires showed minimal structural changes, resulting in only a 1 K fluctuation in surface superheat. The characteristics of increased surface wettability, enhanced liquid supply by capillary force, and increased active nucleation sites in twin-structured nanowires remain stable throughout rigorous boiling tests. This stability ensures that twin-structured nanowires exhibit excellent durability and stability in enhancing boiling heat transfer.