An Mg-1Zn-1Cu-xCe alloys with both high ductility and high thermal conductivity

Although many magnesium alloys with a high ductility have been developed previously, their thermal conductivity are often unsatisfied. An Mg-1Zn-1Cu-xCe (x = 0.2, 0.5) with both a high ductility and a high thermal conductivity (TC) was developed. The mechanical behavior, thermal conductivity and microstructure during hot rolling and annealing treatment were systematically studied. A high thermal conductivity in the range of 145.9-152.9 W/(m center dot K) is obtained in Mg-1Zn-1Cu-xCe (x = 0.2, 0.5) alloys. With the increase of Ce content, the TC of the as-cast alloy increases by approximately 5 W/(m center dot K), while only slightly enhance that of the rolled and annealed plate by approximately 1 W/(m center dot K). The hot rolled and annealed Mg-1Zn-1Cu-xCe (x = 0.2, 0.5) has a high elongation (EL) up to 29.6 % under tension along the rolling direction (RD), together with the highest yield strength (YS) of 114 MPa. The increase of Ce content can improve the maximum YS by approximately 20 MPa, while hardly affects the maximum tensile elongation. A strong anisotropy of yield strength and tensile elongation between RD and transverse direction (TD) is seen in both Mg-1Zn-1Cu-0.2Ce and Mg-1Zn-1Cu-0.5Ce plates. A higher content of Ce increases the number of block phases and transforms the network phases into semi-network phases. After rolling and annealing treatment, the network phases are broken. A weak and TD-spread basal texture is developed, with basal poles spreading and inclining from the normal direction (ND) toward the TD. At last, the mechanisms for the high EL and the high TC in Mg-1Zn-1Cu-xCe alloy is discussed.