氧化氫對AZ31鎂合金硝酸鈰化成皮膜之影響

Effects of Hydrogen Peroxide on the Formation of Cerium Conversion Coatings on AZ31 Magnesium Alloys

方思凱(S. K. Fang) ； 林招松(C. S. Lin)

《防蝕工程》 19卷2期 (2005/06) Pp. 167-175

https://doi.org/10.6376/JCCE.200506.0167

摘要

本研究探討硝酸鈰液中添加過氧化氫對AZ31化成皮膜結構與成長之影響。添加過氧化氫，化成液由澄清透明轉爲橙黃色，公成液中三價鈰離子氧化成四價鈰離子，所生成之化成皮膜爲二氧化鈰。並且由於氫氣泡破玖所造成的震波，關致皮膜嚴重剝落，且皮膜脫落的程度隨化成溫度上昇而加劇。另外橫肉截面TEM觀察顯示，皮膜爲多層結構，其中與底材相鄰的爲多孔的氧氣化鎂，接著爲二氧化鈰，其餘的都爲剝落的二氧化鈰層。

關鍵字

稀土金屬 ； 化成處理 ； 鎂合金 ； 硝酸鈰

並列摘要

The present study details the effects of hydrogen peroxide in the cerium nitrate solution on the microstructure and growth of the conversion coating on AZ31 magnesium alloys. Adding hydrogen peroxide to the cerium nitrate solution changed its color from clear to orange; meanwhile Cr(superscript 3+) was oxidized to Ce(superscript 4+). The major overlay of the coating was cerium oxide that had peeled partially from the substrate due to hydrogen evolution at the interface. Increasing solution temperature from 30 to 60℃ resulted in more serious peeling, when the coating, as characterized by cross-sectional TEM, exhibited a multilayer structure. That is, a porous metal a couple of cerium oxide layers loosely stacking on the surface of the coating.

並列關鍵字

Rare earth metal ； Conversion coatings ； Magnesium alloys ； Cerium nitrate