【摘要】 采用金相显微镜、场发射扫描电镜和透射电镜等仪器，结合电阻测试和显微硬度测试，系统研究了6201铝合金八角棒在不同时效状态下的组织结构演变规律及强度-导电率关系演变规律。结果表明，在人工时效过程中晶粒尺寸、形貌和晶界特征保持不变，主要合金元素从固溶体中逐渐析出形成球形纳米析出相。随着人工时效时间的增加，6201铝合金八角棒的强度与导电率关系呈现明显三阶段特征：172℃(0～1.0)h人工时效，位错回复占主导地位，合金强度下降，主要合金元素开始形成GP区，晶格畸变减轻，导电率升高；172℃(1.0～3.0)h人工时效，GP区逐渐转变为约14 nm的球状β″相，由固溶原子引起的晶格畸变减轻，位错通过机制由切过转变为绕过，强度和导电率同步上升；172℃(3.0～8.0)h人工时效，球状β″相逐渐粗化并转变为针状β’相，强化效应减弱，晶格畸变进一步降低，导致强度下降而导电率升高。6201铝合金八角棒人工时效处理过程中析出相的形貌转变与性能转变的关系，为未来利用纳米析出相与细长晶耦合实现铝合金线材高强高导提供科学依据。更多还原

【Abstract】 Microstructure evolution and strength-electrical conductivity relationship of 6201 aluminum alloy octagonal rod under different aging states were systematically investigated with metallographic microscopy, field-emission scanning electron microscopy, transmission electron microscopy, resistivity test and microhardness test. The results show that grain size, morphology and boundary characteristics remain unchanged, and the major alloying elements gradually change from the solid-solution state to spherical nanoprecipitates. With artificial aging time increasing, the strength-electrical conductivity relationship of the 6201 aluminum alloy octagonal rod exhibits a distinct three-stage characteristic. In the initial stage(0-1.0 h at 172 ℃), dislocation recovery dominates, alloying strength decreases, the main alloying elements begin forming GP zones, lattice distortion reduces and conductivity increases. In the intermediate stage(1.0-3.0 h at 172 ℃), GP zones gradually transform into spherical β″ phases(approximately 14 nm in size), the lattice distortion caused by solution atoms reduces, dislocation mechanism shifts from shearing to bypassing, resulting in simultaneous increases in both strength and electrical conductivity. In the final stage(3.0-8.0 h at 172 ℃), spherical β″ phases are gradually coarsened and transformed into needle-like β′ phases, strengthening effect is weakened, lattice distortion further reduces, ultimately decreasing strength but increasing conductivity. The correlation between the morphological transformation of precipitates and performance evolution during the artificial aging process of 6201 aluminum alloy octagonal rod provides scientific basis for achieving high-strength and high-electrical conductivity aluminum alloy wires by using the coupling of nano-precipitates and elongated grains.更多还原