landing gear is shown in Fig. 18. The new, very large
Airbus aircraft (A-380) mentioned earlier appears
to be committed to a Ti alloy landing gear also,
although the choice of alloy has not been finalized.
The driver for this selection is also weight
reduction and, perhaps, available space if Al alloys
are being considered. This relatively new application
of Ti alloys for landing gear is made possible
by the advancement in b alloy understanding
and production capability.
Another relatively new application of b alloys in
large aircraft is for springs. These Ti alloy springs
replace steel springs at a significant weight
reduction and also eliminate the need for protection
by painting. Because springs are generally loaded
in torsion, fracture is a lesser concern. Consequently
b alloys with very high strengths but low
tensile ductility can be used safely. The alloys are
cold drawn or rolled, coiled into springs and aged
to achieve strengths in excess of 1400 MPa. The
relatively low modulus of b alloys (60–100 GPa)
coupled with the high yield strength permits a very
large elastic displacement range for the spring,