Magnetocaloric properties, microhardness and corrosion resistance of Gd100-xZrx alloys

Abstract

With the intention to improve its mechanical properties and corrosion resistance, the magnetocaloric metal Gd was alloyed with Zr by arc melting and heat treatment. All Gd100–xZrx (x=0, 0.5, 1, 1.5, 2) alloys with various Zr dopings showed hexagonal crystal structure. The Curie temperatures (TCs) of Zr doped alloys were lower than that of Gd by ∼2 K. The maximum magnetic entropy changes of Gd99.5Zr0.5 alloy under magnetic field changes of 0–2 T and 0–5 T were 5.27 and 9.41 J/(kg·K), respectively, which were larger than that of pure Gd metal. The addition of a small amount of Zr increased the microhardness of Gd by at least 29.3%. The corrosion resistance of Gd was also improved by Zr doping, demonstrated by increased corrosion potential and reduced corrosion current density in electrochemical polarization curves measurements. These enhanced properties were beneficial to the potential applications of Gd100–xZrx alloys as magnetic refrigerants at room temperature.