Effects of Zr, Y on the Microstructure and Properties of As-Cast Cu-0.5Y-xZr (wt.%) Alloys

Abstract

In this paper, the microstructure and properties of as-cast Cu-Y-Zr alloys with different Zr content were studied in order to investigate whether the precipitates in copper alloys would interact with each other by adding Y and Zr simultaneously. As-cast Cu-0.5Y-xZr (wt.%, x = 0.05 and 0.1, nominal composition) alloys were prepared by vacuum melting in this study. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to observe the microstructure of the alloys. The mechanical properties of the alloys were tested by universal material testing machine at room temperature. The effects of Zr content on the microstructure and mechanical properties of the alloys were explored. As shown by the research results, in the as-cast Cu-0.5Y-xZr (wt.%) alloys, the precipitated phase was the Cu5Y/Cu5Zr phase and ranged from 10 nm to 70 nm in size; when the Zr content increased from 0.05 wt.% to 0.1 wt.%, both the tensile strength and elongation rate of the alloys increased; when the Zr content was 0.1 wt.%, the tensile strength was 225 MPa and the elongation rate was 22.5%.

Research Progress in Interfacial Characteristics and Strengthening Mechanisms of Rare Earth Metal Oxide-Reinforced Copper Matrix Composites

“…In addition, under the same conditions, the average orientation φ of Cu–Ni–Co–Si–Cr–Ce (11°) is lower than that of Cu–Ni–Co–Si–Cr (16°) [ 13 ]. Liang et al studied the effects of Y and Zr addition on the microstructure and properties of as-cast Cu–Y–Zr alloy [ 14 ]. The results show that, due to the low solid-solubility of Y and Zr in Cu, the amount of precipitated Cu 5 Y and Cu 5 Zr phases increased by adding Y to refine the grains, and thus solid-solution enhancement of Cu–0.5Y–xZr alloy is realized [ 14 ].…”

“…Liang et al studied the effects of Y and Zr addition on the microstructure and properties of as-cast Cu–Y–Zr alloy [ 14 ]. The results show that, due to the low solid-solubility of Y and Zr in Cu, the amount of precipitated Cu 5 Y and Cu 5 Zr phases increased by adding Y to refine the grains, and thus solid-solution enhancement of Cu–0.5Y–xZr alloy is realized [ 14 ]. Saha et al found that adding elemental Sc to Cu–Zn–Al shape-memory alloy can reduce the phase-transition temperature and thus improve the mobility of the martensite/austenite interface [ 32 ].…”

“…Therefore, if the melting point of the reaction product is higher and the density is lower, then the reaction product can be removed from the alloy and reduce the segregation at the grain boundary. (2) Solidification reactions can reduce the influence of impure elements on the surface tension of the alloy [ 14 , 24 , 36 , 50 , 51 ].…”

“…Liang et al found that after Y was added, a zirconium-rich phase in the alloy could easily form nucleation during phase precipitation. Cu 5 Zr phase was precipitated in the solidification process of as-cast Cu–0.5Y–0.1Zr alloy, which promoted the formation of Cu 5 Y phase as an inhomogeneous nucleus and finally formed Cu 5 Y and Cu 5 Zr phases [ 14 ]. Mao et al found that rare earth can remove harmful elements such as S and O in Cu–30Ni alloy and refine the as-cast structure, which has an obvious effect on purifying the melting alloy [ 50 ].…”

“…The addition of the proper amount of rare earth elements or their compounds can improve toughness, plasticity, corrosion resistance and heat resistance [ 13 ]. Recent studies have shown that the addition of rare earth can reduce the probability of electron scattering in copper alloys and thus increase the electrical conductivity to a certain extent [ 14 ]. Rare earth elements can improve the conductivity and mechanical properties of copper alloy to a certain extent because they can purify the melt and refine the grain structure of copper alloys [ 4 , 15 ].…”