| Titre : |
A new phosphate pretreatment process for adhesive bonding of magnesium AZ31 sheets |
| Type de document : |
texte imprimé |
| Auteurs : |
Ming-Zhe Bu, Auteur ; Zhong-Xia Liu, Auteur ; Ting-Ting Wan, Auteur ; Pei-Chung Wang, Auteur |
| Année de publication : |
2013 |
| Article en page(s) : |
p. 347-359 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Anticorrosion
Collage
Durée de vie (Ingénierie)
Magnésium -- Alliages
Phosphate de sodium
Revêtement métallique
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
An economic, high efficiency sodium dihydric phosphate surface pretreatment process (SDPT) was developed to improve the adhesive bond performance of 2 mm thick hot-rolled wrought magnesium AZ31 sheets. A phosphating solution with sodium dihydric phosphate (NaH2PO4), additive sodium fluoride (NaF), and accelerator sodium molybdate (Na2MoO4), sodium tungstate (Na2WO4) and potassium nitrate (KNO3) were developed to pretreat the magnesium alloys. The content of sodium dihydric phosphate in the phosphating solution was strictly controlled to insure it supplied sufficient acid radical HPO4 2− to phosphate magnesium AZ31 alloy. Furthermore, a suitable H+ content to keep the pH values in the range of 5–6 for a phosphating solution was necessary. With this SDPT pretreatment process, a coating consisting of the magnesium phosphate, magnesia (MgO), magnesium hydroxide (Mg(OH)2), magnesium fluoride (MgF2) and a minor amount of molybdenum oxide(MoO3) was formed on the surface of the magnesium AZ31. While the SDPT pretreated adhesive-bonded joints had better initial bond strength than phosphate–permanganate process pretreated joints, the corrosion resistance of SDPT pretreated joints was slightly inferior. |
| Note de contenu : |
- EXPERIMENTAL PROCEDURE : Materials - Surface pretreatment - Potential vs time - Surface characterization - Adhesive bonding of magnesium AZ31 - Quasi-static testing - Environmental exposure - Hydrogen evolution test
- RESULTS AND DISCUSSION : Formation of phosphate coating - Effect of immersion time on coating appearance and thickness - EDS and XPS analyses phosphate coating - Corrosion of phosphated magnesium 1Z31 - Initial bond strength and durability of phosphated magnesium alloys
|
| DOI : |
10.1007/s11998-012-9451-5 |
| En ligne : |
https://link.springer.com/content/pdf/10.1007%2Fs11998-012-9451-5.pdf |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18734 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 10, N° 3 (05/2013) . - p. 347-359
Aller sur edunet
Accueil
A new phosphate pretreatment process for adhesive bonding of magnesium AZ31 sheets in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 10, N° 3 (05/2013)
