Stress corrosion cracking (SCC) is the growth of crack

Transcription

Stress corrosion cracking (SCC) is the growth of crack
Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can
lead to unexpected sudden failure of normally ductile metals subjected to a tensile stress, especially
at elevated temperature in the case of metals. SCC is highly chemically specific in that certain alloys
are likely to undergo SCC only when exposed to a small number of chemical environments.
Aluminum alloys that contain appreciable amounts of soluble alloying elements, primarily copper,
magnesium, silicon, and zinc, are susceptible to stress-corrosion cracking (SCC). Aluminum 7XXX
and 2XXX series are two such alloy series. They find extensive application as aeronautical materials.
Flying such planes above oceans makes them susceptible to SCC.
The Internship project would be related to enhancing corrosion resistance of Al 7XXX and 2XXX
alloys. Thus as a test to appreciate the internee's motivation in this field, the problem statement
would require the student to present a 10 minutes presentation in front of the internship provider
himself. The presentation should comprise of the following points:
1.
2.
3.
4.
Summarize in best possible way the mechanism of stress corrosion.
Brief description about Al 7XXX and 2XXX alloys, their heat treatment and ageing process.
Discuss about SCC in such alloys used to manufacture planes that fly over oceans
Propose compositional changes and alterations in process parameters to increase the
strength of material.
Although experimentation is not necessary, but extensive literature survey is expected from the
participants. Innovative ideas involving changes in design parameters will be appreciated.