Accession Number:

ADA255375

Title:

Evaluation of Corrosion Protection Methods for Aluminum Metal Matrix Composites

Descriptive Note:

Final rept.

Corporate Author:

NAVAL SURFACE WARFARE CENTER DAHLGREN DIV VA

Personal Author(s):

Report Date:

1992-08-01

Pagination or Media Count:

289.0

Abstract:

Corrosion protection of Aluminum Metal Matrix Composites MMC using anodizing, chromate conversion coating and polymer coatings was investigated. Electrochemical Impedance Spectroscopy, DC polarization measurements, and Scanning Electron Microscopy SEM with Energy Dispersive X-ray Spectroscopy EDS were used. The materials studied included 606 1SiC, A356SiC, 2009SiC, 2014Al203 and 6061Al203 in various reinforcement concentrations. The electrochemical behavior of the MMCs without protection was also investigated. MMCs were found to have similar corrosion and pitting potentials as the matrix alloy. The cathodic current density were found to be higher for MMCs with the current density increasing with reinforcement concentration. The increased current density is attributed to the interface between the matrix and the reinforcement particles which increases the corrosion rate. Anodizing was performed on both Al alloys and MMCS. A new model is proposed for Al alloys. Anodizing and hot water sealing on MMCs was less effective than on Al. Improved results were noted for dichromate sealing.

Subject Categories:

  • Polymer Chemistry
  • Laminates and Composite Materials
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE