Microstructure and thermal conductivity of Mg-2Zn-Zr alloy

Mechanical properties and thermal conductivity of Mg-2Zn-Zr alloy were adjusted with mill-annealing and subsequent aging process. The alloy with preferable thermal conductivity, larger than 130 W/(m K), and mechanical properties was obtained. The microstructure, mechanical properties and thermal conductivity are investigated. The average grain size is reduced to 7.8 mm after mill-annealing with a reduction of 75%. The phases of MgZn and ZnZr exist in the as-cast alloy. After aging, the main precipitated phases are ZnZr, Zn2Zr and Zn2Zr3. The precipitation of MgZn is inhibited. The tensile strength is improved by mill-annealing and aging. The peak aged alloy with a rolling reduction of 50% possesses a tensile strength of 279 MPa, a yield strength of 196 MPa and an elongation of 25.2%. The thermal conductivity of the alloy is 132.1 W/(m K). The Mg-2Zn-Zr alloy after mill-annealing and subsequent aging process is a potential preferable thermal conductivity material. (C) 2017 Elsevier B.V. All rights reserved.