Corrosion of Aluminium Alloys by IRFNA (Inhibited Red Fuming Nitric Acid)
Abstract
It has been demonstrated electrochemically (by corrosion potential-time, polarization resistance and Tafel behavior) that the presence of a high concentration of Cu(2+) ions (580 wpm) in IRFNA (Inhibited Red fuming Nitric Acid) does not lead to an increase in the corrosion rate of aluminum alloy in this liquid oxidizer, or to any significant change in the corrosion potential of the system. The effect of the addition of water, to give an appreciably over-propellant specification level (6.75 wt.%H2O), on the corrosion rate of aluminum alloy in IRFNA containing initially 2.79 wt.%H2O) has been investigated by corrosion potential-time polarization resistance and a.c. impedance measurements. The results indicate an order of magnitude increase in corrosion rate and an apparent increase in film thickness, following the addition of water. The effects of variations in IRFNA composition on the corrosion rate of aluminum alloy in IRFNA using four pairs of electrochemical cells, each pair containing IRFNA obtained from a different source, have also been studied. The electrochemical results indicate that the alloy corrodes at a similar rate in IRFNA obtained from three different sources. Auger electron spectroscopy has been used to monitor the effects of certain surface pre-treatments and exposure to IRFNA of samples of aluminum alloy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1989
- Accession Number
- ADA208326
Entities
People
- J. F. Richings
- J. P. Mauger
- M. F. Dove
- N. Logan
Organizations
- University of Nottingham