Ref.: MmeEte34-001
Apresentador: Larissa Perego Mendes
Autores (Instituição): Mendes, L.P.(Laboratório de Tubos de Calor); Amaral, M.C.(Laboratório de Tubos de Calor); Caldas, L.d.(Laboratório de Tubos de Calor); Martins, B.M.(Laboratório de Tubos de Calor); Domiciano, K.G.(Laboratório de Tubos de Calor); Krambeck, L.(Laboratório de Tubos de Calor); Xavier, F.A.(Universidade Federal de Santa Catarina); Mantelli, M.B.(Laboratório de Tubos de Calor);
Resumo:
Heat pipes are used mainly as an effective heat transfer or a temperature homogenization. They consist of heat transfer devices that use two-phase cycles of fluids as the operating principle. These devices may have many sizes, geometries and configurations as well be used in a variety of applications, from large offshore platforms to electronic devices such as smartphones and tablets. This work emphasizes loop heat pipes applied mainly on smartphones, where size and thickness should be as lower as possible.
Diffusion bonding excels in manufacturing these devices, producing sound joints while avoiding undesirable flatness deformation. In diffusion bonding, two or more contacting surfaces are welded in solid-state, with application of sufficient temperature and pressure during a period of time. The current study investigated the impact of process parameters on the diffusion bonding of electrolytic copper applied for heat pipe manufacturing. Temperatures ranging from 825 ºC to 875 ºC, as well pressures up to 11 MPa were evaluated. The joint quality was qualitatively assessed via microstructural characterization in optical microscope (OM) and scanning electron microscope (SEM), and quantitatively through shear strength. Furthermore, diffusion bonded heat pipes were manufactured from the evaluated parameters and its quality was determined using leakage test and visual inspection of the deformation evolution, as well as microstructural characterization and thermal tests.