The aim of this work is to study the influence of pulsed current on hard anodizing process (in sulphuric acid bath) of AA 7075-T6, a commercial heat treated aluminium alloy widely used in several innovative and strategic mechanical sectors (military, automotive, aerospace, etc).Exploiting different pulsed current procedures (slow square pulse mode), combining different duty cycles and current levels it was possible to obtain thick and hard anodic oxides with a good interfacial adhesion. The optical microscopy characterization shows that the use of pulsed current minimizes the growth of defects at the oxide/alloy interface caused by the presence of intermetallic precipitates characteristic of AA 7075-T6. Moreover nano-indentation profiles, evaluated along the coatings cross section, highlight the oxide hardness increase of the samples obtained employing pulsed current cycles (PC) compared to those obtained with standard direct current process (DC) or multistep direct current procedures (MSDC).

Pulsed current effect on hard anodizing process of 7075-T6 aluminium alloy / Bozza, Andrea; Giovanardi, Roberto; Manfredini, Tiziano; Mattioli, Paolo. - In: SURFACE & COATINGS TECHNOLOGY. - ISSN 0257-8972. - ELETTRONICO. - 270:(2015), pp. 139-144. [10.1016/j.surfcoat.2015.03.010]

Pulsed current effect on hard anodizing process of 7075-T6 aluminium alloy

BOZZA, ANDREA;GIOVANARDI, Roberto;MANFREDINI, Tiziano;
2015

Abstract

The aim of this work is to study the influence of pulsed current on hard anodizing process (in sulphuric acid bath) of AA 7075-T6, a commercial heat treated aluminium alloy widely used in several innovative and strategic mechanical sectors (military, automotive, aerospace, etc).Exploiting different pulsed current procedures (slow square pulse mode), combining different duty cycles and current levels it was possible to obtain thick and hard anodic oxides with a good interfacial adhesion. The optical microscopy characterization shows that the use of pulsed current minimizes the growth of defects at the oxide/alloy interface caused by the presence of intermetallic precipitates characteristic of AA 7075-T6. Moreover nano-indentation profiles, evaluated along the coatings cross section, highlight the oxide hardness increase of the samples obtained employing pulsed current cycles (PC) compared to those obtained with standard direct current process (DC) or multistep direct current procedures (MSDC).
270
139
144
Pulsed current effect on hard anodizing process of 7075-T6 aluminium alloy / Bozza, Andrea; Giovanardi, Roberto; Manfredini, Tiziano; Mattioli, Paolo. - In: SURFACE & COATINGS TECHNOLOGY. - ISSN 0257-8972. - ELETTRONICO. - 270:(2015), pp. 139-144. [10.1016/j.surfcoat.2015.03.010]
Bozza, Andrea; Giovanardi, Roberto; Manfredini, Tiziano; Mattioli, Paolo
File in questo prodotto:
File Dimensione Formato  
Accepted_Manuscript.pdf

accesso aperto

Tipologia: Post-print dell'autore (bozza post referaggio)
Dimensione 863.25 kB
Formato Adobe PDF
863.25 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11380/1073789
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 41
  • ???jsp.display-item.citation.isi??? 36
social impact