Effects of cerium on microstructure and mechanical properties of ZK60 alloy

Abstract

ZK60-xcerium alloys were studied, where x mass fraction is 0, 0.52%, 0.94%, 1.51% and 1.98%, respectively. Influence of Ce contents and heat-treatment on microstructure and tensile properties was analyzed. The results show that cast ZK60 alloy containing no Ce has coarse crystal grains, and lots of segregation aggregates around the grain-boundary. However, the alloys containing Ce have refined grains, and grain-boundaries are purified at the same time. Obvious dynamic recrystallization occurs in tested alloys after hot-extrusion. Tensile strength heightens with the increase of Ce content, and grows higher after aging at 150 °C for 0–24 h (T₅ treatment). Comparing tensile properties of investigated alloys in different states, it can be concluded that synthetical properties of the alloy with 1.51% Ce addition is the best of all. In extruded state, σ_b and δ of this alloy are 318.6 MPa and 14.4%, respectively. After aging for 24 h, σ_b is 338.6 MPa and δ is 15.6%.

Keywords

ZK60 alloy / Cerium / hot-extrusion / dynamic recrystallization / microstructure / mechanical properties