Heat transfer of liquid metal alloy on copper plate deposited with film of different surface free energy*

Abstract

Liquid metal alloys (LMAs) are the potential candidates of thermal interface materials (TIMs) for electronics cooling. In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies (SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.

Effect of seed layers on the static and dynamic magnetic properties of CoIr films with negative effective magnetocrystalline anisotropy

“…, and Ti (2.570 J•m −2 ) are smaller than that of Co (2.709 J•m −2 ). [24,25] As the Ir atomic diameter is bigger than that of Co, the lattice constant of the hcp-CoIr phase becomes bigger with the increase in Ir. We speculate that the surface-free energy of Co is smaller than that of CoIr.…”

Experimental Investigation of the Anisotropic Thermal Conductivity of C/SiC Composite Thin Slab

“…With the measured specific heat capacity 𝑐p and density 𝜌, the 𝜆 along the sample test direction can be obtained by 𝜆 = 𝑎 • 𝜌 • 𝑐p. [29] The LFA467 (NETZSCH, Germany) was adopted to measure the 𝑎 out-of-plane of 2D plain woven C/SiC composite within the temperature ranges from 150 ∘ C to 900 ∘ C. The STA449F3 simultaneous thermal analyzer (STA) (NETZSCH, Germany) was employed to measure the temperature-dependent specific heat capacity.…”

Accurate determination of anisotropic thermal conductivity for ultrathin composite film

“…Usually, in-plane and cross-plane thermal conductivity λ x and λ z of thick composite film are determined by using laser flash techniques by heating the films in the center with a laser pulse and measuring its in-/cross-plane thermal response (surface temperatures) at the edge/rear with an infrared detector. [7][8][9][10] However, this method is in question for the thermal property measurement of ultrathin composite films. [11] For cross-plane measurements, on the one hand, ultrathin film reaches a thermal equilibrium state in the crossplane direction within a very short time, and visible temperature difference could be hardly obtained.…”