Effects of Ag Content and Hot-Rolling on Microstructure and Mechanical Properties of Zn-Cu-xAg-Zr Alloy.

The effects of Ag content and hot-rolling on the microstructure and mechanical properties of Zn-1.5Cu-xAg-0.1Zr(x = 0, 0.1, 0.5, 1.0) alloys were investigated. The microstructure, phase composition and fracture morphology of the alloys were observed and analyzed by optical microscope, x-ray diffraction, scanning electron microscope, energy dispersive spectrometer and universal mechanical testing machine. The results show that Ag has the effect of grain refinement. After alloying, the grain size of as-cast Zn-1.5Cu-xAg-0.1Zr alloy decreased first and then increased, and the minimum grain size of as-cast Zn-1.5Cu-0.5Ag-0.1Zr alloy was refined to 64.18 μm. At the same time, new phase AgZn₃ began to precipitate, the yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) of alloys were also up to 97.35 MPa, 139.25 MPa and 7.60%, respectively. After hot-rolling, the grain of Zn-1.5Cu-xAg-0.1Zr alloy was broken and new phase CuZn₅ was precipitated. The mechanical properties were significantly improved, and the maximum YS, UTS and EL of as-rolled Zn-1.5Cu-1.0Ag-0.1Zr alloy were 218.14MPa, 244.83MPa, 64.50%, respectively. [ABSTRACT FROM AUTHOR]