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研究机械合金化制备的纳米晶Mg-6Al-1Zn和Mg-6Al-1Zn-1Si合金的热稳定性和晶粒生长动力学。研究从元素粉末开始,使用了各种分析手段,包括差示扫描量热法(DSC)、X射线衍射(XRD)、扫描电镜、透射电镜和能谱分析。研究等温退火过程中的晶粒生长动力学。XRD结果表明:尽管两种材料体系的晶粒尺寸随退火温度的升高而增加,但在350°C退火1 h后,含Si体系具有更小的晶粒尺寸(60 nm),而Mg-6Al-1Zn体系的晶粒尺寸为72 nm。Mg-6Al-1Zn-1Si体系在等温退火过程中形成的第二相金属间化合物Mg2Si不仅影响活化能,而且影响动力学方程的指数。含Si体系的硬度更高是由于金属间相Mg_2Si的形成。
The thermal stability and grain growth kinetics of nanocrystalline Mg-6Al-1Zn and Mg-6Al-1Zn-1Si alloys prepared by mechanical alloying were investigated. Studies Starting with elemental powders, a variety of analytical tools were used, including differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy and energy spectrum analysis. Study of grain growth kinetics during isothermal annealing. XRD results show that although the grain sizes of the two materials increase with the annealing temperature, the Si-containing system has a smaller grain size (60 nm) after annealing at 350 ° C for 1 h, whereas the Mg- The grain size of 6Al-1Zn system is 72 nm. The second phase intermetallic Mg2Si formed during isothermal annealing of Mg-6Al-1Zn-1Si system not only affects the activation energy but also affects the index of kinetic equation. The higher hardness of Si-containing systems is due to the formation of intermetallic phase Mg 2 Si.