摘要
The microstructures and interface structures of basalt particle reinforced 7A04 Al matrix composites (BP/7A04 Al) were analyzed by using OM, TEM, SEM and EDS, and the mechanical properties of 7A04 Al alloy were compared with those of BP/7A04 Al matrix composites. The results show that the basalt particles are dispersed in the Al matrix and form a strong bonding interface with the Al matrix. SiO2 at the edge of the basalt particles is continuously replaced by Al2O3 formed in the reaction, forming a high-temperature reaction layer with a thickness of several tens of nanometers, and Al2O3 strengthens the bonding interface between basalt particles and Al matrix. The dispersed basalt particles promote the dislocation multiplication, vacancy formation and precipitation of the matrix, and the precipitated phases mainly consist of plate-like η(MgZn2) phase and bright white band-shaped or ellipsoidal T (Al2Mg3Zn3) phase. The bonding interface, high dislocation density and dispersion strengthening phase significantly improve the mechanical properties of the composites. The yield strength and ultimate tensile strength of BP/7A04 Al matrix composites are up to 665 and 699 MPa, which increase by 11.4% and 10.9% respectively compared with 7A04 Al alloy without basalt particles.
采用金相显微镜(OM)、透射电镜(TEM)、扫描电镜(SEM)和能谱(EDS)分析玄武岩颗粒增强7A04铝基复合材料的显微组织和界面结构,对比研究7A04铝合金和BP/7A04铝基复合材料的力学性能。研究结果表明:玄武岩颗粒在铝基体中弥散分布,并与铝基体形成强力结合界面,玄武岩颗粒边缘的SiO2不断被反应生成的Al2O3取代,形成一层几十纳米厚度的高温反应层,反应生成的Al2O3强化了玄武岩颗粒与铝基体的结合界面;弥散分布的玄武岩颗粒可促进基体中位错增殖、空位形成和析出相的析出,析出相主要以板状的η(MgZn2)相和亮白色条状或椭球状的T(Al2Mg3Zn3)相为主,结合界面、高位错密度及弥散分布的强化相显著提高复合材料的力学性能,BP/7A04铝基复合材料的屈服强度和极限拉伸强度分别达到665和699MPa,与未添加玄武岩颗粒的7A04铝合金相比分别提高11.4%和10.9%。
基金
Projects(2019JJ60050,2018JJ3121) supported by the Natural Science Foundation of Hunan Province,China
Project(KFBM20170004) supported by the Jiangsu Province Key Laboratory of Materials Surface Science and Technology,China
