目前直接使用现有的电解双喷法或离子减薄法都不能制备适合在透射电镜（TEM）下观察的非均匀化处理的硅含量5%（质量分数）以上铸造铝合金样品。分别对采用两种方法和将两种方法结合制备的样品进行观察。结果表明：在电解双喷液中加入氢氟酸可改良硝酸甲醇溶液，消除合金中硅的不利影响，样品的表面质量会有一定改善，但还满足不了薄区的要求；加入单乙醇胺调节硝酸氢氟酸甲醇溶液的pH在6~7，不能改善样品的表面质量。使用离子减薄法制备铝合金样品，样品厚度大于50 mm时，由于轰击时间较长样品变成了非晶态；当样品厚度小于50 mm时，样品强度偏低，在外力作用下容易发生变形，不方便在透射电镜下多次观察。使用电解双喷法和离子减薄法相结合的方法能获得可在透射电镜下观察的样品，是目前制备非均匀化处理硅含量5%以上铸造铝合金透射电镜样品既经济又合理的手段。

At present, the direct use of the existing electrolytic double spray method or ion thinning method can not prepare the cast aluminum alloy samples with more than 5% (mass fraction) silicon content which are suitable for transmission electron microscope (TEM) observation. The samples prepared by two methods and the combination of the two methods were observed. The results show that with the addition of hydrofluoric acid to the electronic double spary solution could modified methanol nitrate solution, eliminationg the adverse effect of silicon in alloy, the surface quality of samples were improved, but it could not meet the requirements of the thin area. The addition of monoethanolamine to regulate the pH value of the methanol solution of hydrofluoric acid in 6~7 could not improve the surface quality of samples. Aluminum alloy samples were prepared by ion thinning method. When the thickness of the sample was more than 50 mm, the sample became amorphous due to the longer bombardment time. When the thickness of the sample was less than 50 mm, the strength of the sample was low, and it was easy to deform under the action of external force, which was not convenient to observe by TEM for many times. The samples could be observed by TEM, prepared by the combination of electrolyitic double spray method and ion thinning method. This method is a economic and reasonable for preparing the TEM samples of cast aluminum alloy with silicon content more than 5% after non-uniform.