论文部分内容阅读
利用X射线衍射分析(XRD)、差示扫描量热法(DSC)和拉伸试验,研究不同温度等通道转角挤压(ECAP)和常规静态时效处理后6013 Al-Mg-Si铝合金的微观结构、时效行为、析出动力学以及力学性能。XRD测得的ECAP变形后合金的平均晶粒尺寸在66~112 nm范围内,平均位错密度在1.20×1014~1.70×1014 m-2范围内。DSC分析表明,由于ECAP后试样比常规时效处理试样拥有更细小的晶粒和更高的位错密度,因此,ECAP变形后合金的析出动力学更快。与未变形合金相比,ECAP后试样的屈服强度和抗拉强度都得到了显著提高。室温ECAP后试样的强度达到最大,其屈服强度是静态峰时效屈服强度的1.6倍。细晶强化、位错强化以及由于ECAP过程中的动态析出而产生的析出相强化,是ECAP合金获得高强度的几种主要强化机制。
X-ray diffraction (XRD), differential scanning calorimetry (DSC) and tensile test were used to study the microstructure of 6013 Al-Mg-Si aluminum alloy after ECAP and conventional static aging treatment Structure, aging behavior, precipitation kinetics and mechanical properties. The average grain size of alloy after ECAP deformation measured by XRD is in the range of 66 ~ 112 nm, and the average dislocation density is in the range of 1.20 × 1014 ~ 1.70 × 1014 m-2. DSC analysis shows that the precipitation kinetics of ECAP after ECAP deformation are faster because ECAP samples have finer grains and higher dislocation density than those of conventional aging samples. Compared with the untransformed alloy, the yield strength and the tensile strength of ECAP samples have been significantly improved. After the ECAP at room temperature, the strength of the sample reached the maximum, its yield strength is 1.6 times of the static peak aging yield strength. Grain refinement, dislocation strengthening and precipitated phase strengthening due to dynamic precipitation during ECAP are some of the major strengthening mechanisms for obtaining high strength ECAP alloys.