材料期刊网

以自行制备的高合金含量的 Al-Zn-Mg-Cu 合金为试验材料，测试观察挤压带板及其制备的等温模锻件的织构类型及组分强度、组织结构、平面拉伸力学性能及各向异性指数，通过计算｛111｝＜112＞滑移系的施密特因子，采用单晶近似法分析平面拉伸力学性能各向异性与织构的关系，使用霍尔-佩奇定律分析了组织结构与平面拉伸力学性能各向异性的关系，结果表明：合金经剧烈变形后，以变形织构为主，变形织构会引起各向异性，导致合金45°方向强度偏低；挤压形成的纤维组织是引起挤压带板 L 向及 LT 向各向异性的主要原因。｛110｝＜112＞Brass织构强度增加，可以抵消纤维组织引起的 L 向及 LT 向的各向异性；LT 向伸长率低及伸长率各向异性主要是由第二相粒子延晶界的链状分布引起，同时也与织构引起的晶粒强度变化有很大关系。

In order to master the impact of texture and microstructure on the in-plane anisotropy of tensile mechanical properties of ul-tra-high strength Al-Zn-Mg-Cu alloy ,the extruded plate and its isothermal forged piece were manufactured.The microstructure,tensile mechanical properties and the intensity of texture were tested and the Schmidt factors were calculated.The relationship of the texture, microstructure and the tensile strength anisotropy were observed by means of single crystal model with Schmidt factor and Hall-Petch law.The results show that the alloy is dominated by deformation texture after intense deformation,and deformation textures leads lower strength of 45°and causes anisotropies.Fibrous tissue formed by extrusion is the main reason of the anisotropy in L and LT directions. The increased strength caused by {1 10} <1 12 >Brass texture can counterbalance the anisotropy in L and LT directions caused by fi-brous tissue.The chainlike distribution of the second phase particles in grain boundary is the key factor of lower elongation of LT and the elongation anisotropy,also it is relevant to the grain strength changes caused by textures.