另外，简单介绍一些操作技术。必须先声明，我个人从未进行过具体的操作。这里的经验是别人的。

铝合金电解抛光和复膜具体过程、配比和方法如下：

电解抛光液选用45gCrO₃+285mlH₃PO₄+70ml H₂SO₄ +100mlH₂O 溶液，抛光电压为15V左右，时间1～2分钟；

阳极覆膜液选用11gH₃BO₃（硼酸）+ 20ml HF+1000mlH₂O溶液，覆膜电压为20V左右，时间7～8分钟。

注意：这些是基本条件，具体的时间、电压等工艺参数还要根据铝合金的种类和试样的大小进行一些改变。配方一般就是这个，没有什么改变。（个人理解：这里的复膜液，是Barker's reagent的变通；很实际）

所谓Barker's reagent就是：

4 to 5 ml fluoroboric acid（氟硼酸，HBF₄）in 200ml water, electrolytic anodizing at 20 to 22V during 90 to 180s

http://www.metallography.com/experts/faq.html#Al

另外一个验证的渠道是来自于Polarized light microscopy: utilization in the investigation of the recrystallization of aluminum alloys，M. Sla´mova´，V. Ocˇena´sˇek，G. Vander Voort；Materials Characterization 52 (2004) 165– 177：

……Barker’s reagent, consisting of 4–5 ml HBF₄ （48%） in 200 ml H₂O.

在Polarized light microscopy: utilization in the investigation of the recrystallization of aluminum alloys这篇文章中，有一段涉及描述阳极氧化复膜的文字，如下：

The samples for PLM observations of grain structure are prepared by the usual procedure of mounting, mechanical grinding and polishing. After polishing, the samples are anodized by electrolytic etching at 20 V DC in Barker’s reagent, consisting of 4–5 ml HBF4 (48%) in 200 ml H2O. The etching is aimed at depositing a film of Al2O3 on the surface. In polycrystalline materials, the thickness of the film formed on each particular grain depends on the grain’s crystallographic orientation. When viewed with planepolarized illumination passed through an analyzer, the film can rotate the plane of polarization regarding the orientation of the underlying grain, thus producing various shades of black, gray or white. The contrast effects can be converted to striking color contrast by inserting before the polarizer a sensitive tint or quarter- wave plate.

G. Vander Voort在这里强调的是膜层厚度有差异；完全没有提到各向异性膜层性质的影响。

在ASM Handbook Volume 9：Metallography and Microstructures；2004中，有几个地方涉及Barker's reagent；除了阳极氧化的文字论述中以外，还有，一个侵蚀剂表格，两张照片。

p1735  Table 14 Reagents for electrolytic microetching

P257

Fig. 11 Feather crystals in an alloy 3003 ingot cast by the direct-chill semicontinuous process. Growth twins in the crystals. Polarized light. Barker's reagent. Original magnification 50×. Source: Ref 4

p1235

Fig. 16 Grain structure of wrought 1100-grade aluminum foil after electrolytic polishing and anodizing with Barker's reagent (20 V direct current, 2 min). (a) Viewed with bright-field illumination, revealing only the intermetallic precipitates. If anodizing had produced an interference film, colored grains should be visible. (b) Viewed with polarized light and (c) with polarized light plus a sensitive tint filter. The magnification bars in (b) and (c) are 100 μm long. (d) As-cast (concast) 1100 aluminum (>99% Al) anodized with Barker's reagent (30 V direct current, 2 min), revealing a dendritic solidification structure. Viewed with crossed polarized light plus sensitive tint

前面侵蚀剂表格中提到的Ref 7, 9, 10，在p1776的References cited in this section中可以看到：

……

7. Metallography and Microstructures, Vol 9, Metals Handbook, 9th ed., American Society for Metals, 1985, p 351–388

8. M. Orman, Metalografia Aluminium (Metallography of Aluminum), Wyd. Śląsk, Katowice, 1957

9. G. Petzow, Metallographic Etching, 2nd ed., ASM International, 1999

10. “Standard Methods for Microetching Metals and Alloys,” E 407–70, American National Standard Institute/ASTM, reapproved 1976

……