Effect of Aluminum Coating on Corrosion and Heat Transfer Performance of Magnetic Refrigerant Gadolinium

Abstract

The surface of gadolinium was covered with a layer of Al film(10–15 µm) by hot-press. Corrosion resistance, thermal conductivity and diffusivity of the composites were studied. As a result, temperature and pressure are the main factors that influence the combination of Gd and Al, and the effect of pressure is especially obvious. When the pressure exceeds 700 MPa, the binding force reaches 9 MPa. After coating, corrosion resistance of the composites is significantly improved, Corrosion rate is significantly reduced and mass loss reduced to one-tenth of pure Gd after 15 days. The current density decreases by an order of magnitude and corrosion potential increases by 0.3 V. The thermal conductivity of the composites is 11.12 W·m⁻¹·K⁻¹. Due to good thermal diffusion coefficient of aluminum, the magnetic work piece coated with Al film might show better heat transfer performance.

Keywords

magnetic Refrigeration / Gd / Al coating by hot press / corrosion / thermal conductivity and diffusion