... constant.
Chapter 14: Metal processing
Forming pressure
No friction
p
f
=
σ
y
.
Symbols and formulae 371
Symbol Meaning(units)
m mass (kg)
m Weibull modulus (dimensionless)
M bending moment (N m)
M
F
martensite ... Index
Moduli of
ceramics and glasses 164, 177
composites 265, 266
foams 273
metals 12
polymers 224, 239
woods 278
Modulus of rupture 164, 181
Monel 7, 12
Mould design...
... environment.
Fine-grained castings
Many engineering components – from cast-iron drain covers to aluminium alloy cylin-
der heads – are castings, made by pouring molten metal into a mould of the ... be watched. The casting “material”
used is ammonium chloride solution, made up by heating water to 50°C and adding
ammonium chloride crystals until the solution just becomes saturated. The soluti...
... processing method
could be introduced with economic benefits.
Background reading
M. F. Ashby and D. R. H. Jones, Engineering Materials I, 2nd edition, Butterworth-Heinemann, 1996.
Further reading
S. ... mm, or less.
14.4 Aluminium sheet is to be rolled according to the following parameters: sheet
width 300 mm, starting thickness 1 mm, reduced thickness 0.8 mm, yield strength
100 M...
... worked or heat-treated into
finished products; and by understanding these, shape and size can, to a large extent,
be predicted.
Background reading
M. F. Ashby and D. R. H. Jones, Engineering Materials ... what moving the molten zone along the bar has done to it: we
have removed impurity from the left-hand end of the bar and dumped it at the right-
hand end; that is, we have zone refine...
... devel-
oped for use in the aerospace industry, they are now much more widely used. The
dominant use of aluminium alloys is in building and construction: panels, roofs, and
frames. The second-largest ... equilibrium temperature. If, instead of using undersaturated
ammonium chloride solution, we pour saturated solution into the mould, we get what
is called “big-bang” nucleation. As the freshly...
... wear and tear. Untempered martensite is far too brittle for hammer
heads.
Having solved the immediate problem to our satisfaction we still wondered how the
manufacturer had managed to harden the ... bath of
molten salt at 450°C. Finally, the heads are removed from the tempering bath and
washed in cold water. The rather complicated austenitising treatment is needed be-
cause the Standard insis...
... then re-assembled and poured. When the casting has gone solid it
is removed by destroying the mould. Metal moulds are machined from the solid. They
Production, forming and joining of metals 143
Chapter ... of a shaped casting will directly determine the strength of the finished article.
Gas pores should be avoided, so the liquid metal must be degassed to remove dissolved
gases (either by addin...
... sliding, and allowing the clay to be formed
by hand or with simple machinery. When the shaped clay is dried and fired, one com-
ponent in it melts and spreads round the other components, bonding ... defect in the small volume subjected to the highest
stresses is small.
18.3 Modulus-of-rupture tests were done on samples of ceramic with dimensions
l = 100 mm, b = d = 10 mm. The median value of...