Cu-Y合金高温氧化膜组织结构分析

许多工作指出在铜中加稀土可提高铜材抗氧化性,从动力学上看,被归因于氧化扩散激活能E的提高。E的提高只代表氧化动力学过程的一种统计效果,揭示不了氧化膜组织结构的变化以及这种变化对氧化膜生长过程的影响。事实上许多合金加稀土提高抗氧化性,归根到底是通过改善氧化膜组织结构实现的。

Effects of Y addition on structural and mechanical properties of CuZrAl bulk metallic glass

The effects of Y addition on the structural and mechanical properties of CuZrAl bulk metallic glass（BMG） were studied.The results show that the glass forming ability of CuZrAl system is improved by the addition of Y and the fracture strength decreases with Y addition due to the reduction of binding energy induced by Y.The fracture surface is dominated by vein-like patterns in Cu45Zr48Al7 bulk metallic glass,and changes to smooth regions in Cu46Zr42Al7Y5 BMG.TEM observation shows that Cu45Zr48Al7 BMG has a composite microstructure of nanocrystalline phases dispersed in amorphous matrix.However,the Cu46Zr42Al7Y5 BMG shows a fully amorphous structure.

Effects of alloying and deformation on microstructures and properties of Cu-Mg-Te-Y alloys

New copper alloys with high mechanical properties and high electrical conductivity were prepared, and the effects of addition of minor Mg and Y elements on microstructures and properties were studied. The high tensile strength of above 510 MPa, high elongation of 11%and high electrical conductivity of over 63%IACS can be simultaneously obtained in Cu-0.47Mg-0.20Te-0.04Y alloy after deforming and annealing treatment. Effects of purification together with the grain refining by Y and solid-solution strengthening by Mg are appropriate for enhancing mechanical properties and electrical conductivity of the copper alloys.

Effects of rolling and annealing on microstructures and properties of Cu-Mg-Te-Y alloy

Microstructures and element distributions of the as-cast, hot-rolled and cold-rolled Cu-Mg-Te-Y alloys were studied. Effects of rolling process and annealing temperature on the properties of the Cu-Mg-Te-Y alloys were correspondingly investigated. The results indicate that the Mg element is homogeneously distributed in the matrix and the fragmentized Cu2Te phase is dispersed in the matrix after hot rolling. Then, the Cu2Te phase is further stretched to strip shape after the cold rolling process. The microstructures of the cold-rolled alloy keep unchanged for the sample annealed below 390 ℃ for 1 h. However, after annealing at 550 ℃ for 1 h, the copper alloy with fibrous microstructures formed during the cold rolling process recrystallizes, leading to an obvious drop of hardening effect and an increase of electrical conductivity. The Cu-Mg-Te-Y alloy with better comprehensive properties is obtained by annealing at 360-390 ℃.

Y对Cu的显微组织和性能的影响

借助金相显微镜、扫描电子显微镜、能谱仪、透射电镜、X射线衍射仪及涡流电导率仪、硬度仪研究了真空感应制备的Cu-Y合金的组织和性能。实验结果表明,Cu-Y合金的组织随着Y含量的增大而不断细化,未固溶的Y元素在Cu中以中间相化合物六方Cu7Y的形式富集在晶界处,退火后Cu7Y相会分解为立方Cu5Y相。Cu-Y合金的导电率随Y含量的增加会先上升再降低,当Y含量为0.05%时导电率达到最大102%IACS。而显微硬度随着Y含量的增加而不断升高,主要硬化机制为细晶硬化和第二相硬化。