摘要
The effects of TiB_(2) and Zr on the microstructure,aging response and mechanical properties of hot-extruded Al-Zn-Mg-Cu based materials were investigated and compared by multi-scale microstructure characterization techniques.The results showed that proper addition of TiB_(2) particles could refine grain size during solidification,promote dynamic recrystallization during extrusion,and inhibit grain growth during solution treatment.Meanwhile,Zr addition had minor influence on the grain refinement during solidification,but could effectively suppress recrystallization and grain growth compared with the Zr-free alloy.Furthermore,the TiB_(2) addition could simultaneously enhance the aging kinetics and peak-aged hardness of the materials.Comparatively,Zr addition could also improve the peak-aged hardness with minor effect on the aging kinetics of the materials.Finally,the quench sensitivity,elastic modulus and tensile properties of the materials were compared and studied.Specifically,the relationship between the microstructure and mechanical properties,and the strengthening mechanisms were discussed in detail.
采用多尺度显微组织表征技术研究TiB_(2) 和Al_(3)Zr对热挤压Al-Zn-Mg-Cu基材料的显微组织、时效响应和力学性能的影响。结果表明,添加适量TiB_(2) 颗粒在凝固过程中能有效细化晶粒,挤压过程中能促进动态再结晶,固溶过程中能有效抑制晶粒长大。同时,与无Zr合金相比,Zr元素的添加在凝固过程在对晶粒细化无明显影响,但可以有效抑制再结晶和晶粒长大。TiB_(2) 颗粒能加快材料的时效动力学并且提高峰时效硬度;Zr元素也能提高材料的峰时效硬度,但对时效动力学无明显影响。最后,分析不同材料的淬火敏感性、弹性模量和拉伸性能,并研究此类材料显微组织与力学性能之间的关系及其强化机理。
基金
financial supports from the China Postdoctoral Science Foundation(Nos.2019TQ0193,2019M661497)
the National Key Research and Development Program of China(No.2018YFB1106302)
the National Natural Science Foundation of China(No.51821001)
the Anhui Provincial Engineering Research Center of Aluminum Matrix Composites,China(No.2017WAMC002)。
