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Materials Congress 2018
Page 28
Nano Research & Applications
ISSN: 2471-9838
W o r l d C o n g r e s s o n
Materials Science & Engineering
A u g u s t 2 3 - 2 5 , 2 0 1 8
Am s t e r d a m , N e t h e r l a n d s
E
ntrainment defects from the casting process are inherited by the solidified
metal, leading to defects which are the source of the universal crack
initiators, the Griffith cracks in metals. Examination of existing and accepted
crack initiating mechanisms finds them all wanting; none currently appear to
explain crack formation and propagation. It follows that the inherited casting
defects may be the only source of failure. The elimination of these defects,
which appears to be possible, should therefore lead to the elimination of
cracking in metals. Evidence is accruing to indicate the truth of this prediction.
The consequent elimination of the common failure processes such as fatigue,
creep, stress corrosion cracking, etc. all appear possible. For aerospace, an
enhanced electroslag (ESR) process for steels and Ni alloys is recommended
but vacuum arc remelting (VAR) is not, it appears to be fundamentally flawed
and unsuitable for safety critical applications.
Biography
John Campbell is a Physicist from Cambridge, Sheffield and
Birmingham Universities. His interest is in the Liquid and Solid
States during Metal Manufacture. He has worked in industry,
developing casting processes, building and running casting
operations for much of his life. As a Prof of Casting Technology
at the University of Birmingham, he is responsible for the bifilm
concept, and the development of the naturally pressurised
filling system design for castings. He is the author of too many
papers and patents and several books: his ‘Complete Casting
Handbook’ is not for the faint-hearted. He is an indefatigable
promoter for the manufacture of defect-free cast products.
jc@campbelltech.co.ukFailure by cracking
John Campbell
University of Birmingham, United Kingdom
John Campbell, Nano Res Appl 2018, Volume: 4
DOI: 10.21767/2471-9838-C4-017