摘要
采用光学显微镜(OM)、扫描电镜(SEM)和X射线衍射(XRD)等分析手段,研究固溶温度对6061铝合金热挤压板材的显微组织、力学性能及拉伸断口形貌的影响。结果表明,实验合金的强度和硬度随着固溶温度的升高而提高,当基体有轻微过烧时强度并没有降低;实验合金的最佳固溶工艺为565℃×40 min。XRD物相分析表明,在固溶处理过程中发生溶解的析出相粒子主要为Mg2Si,而残留的粗大析出相则主要是富Fe化合物。通过基体点阵常数的精确测量可以很好的表征合金的固溶程度。固溶处理后残留的析出相粒子是影响合金拉伸断口形貌的主要因素。当固溶温度低于535℃时,合金的断裂属于单一的韧窝断裂;当固溶温度高于535℃时,合金的断裂是由沿晶脆性断裂和韧窝断裂组成的混合断裂。
Effects of solution temperature on microstructure, mechanical properties and fracture morphology of a 6061 aluminum alloy were investigated by optical microscope（OM） , scanning electron microscope （SEM） and X-ray diffraction （XRD）. The results show that the strength and hardness can be enhanced with increasing the solution temperature in the range of 515-595 ℃ even if the slightly burnt stcueture is obsreved at 595 ℃. The tensile tests indicate that the optimum solution regime of the investigated alloy sheet is solution at 565 ℃ for 40 min. The results of XRD show that the resolved particles are Mg2Si while the remaining phase is iron-rich phase during solution treatment. The accurate measuring on the lattice parameter of the ct（A1） matrix can be used to characterize the solution degree of the alloy. It is found that the fracture morphology is mainly affected by the volume fraction of residual particles. The fracture morphology shows dimpled rupture when the solution temperature is lower than 535 ℃ while mixture mode of dimpled rupture and intergranular brittle fracture is observed when higher than 535 ℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第5期131-136,共6页
Transactions of Materials and Heat Treatment
基金
中国博士后科学基金(2012M511552)
广东省重大科技专项(2009A080205001)
关键词
固溶温度
微观组织
力学性能
断口形貌
solution temperature
microstructure
mechanical property
fracture morphology
