1. Titanium 6AL-4V in Aircraft
Sahithi Chatradi
Materials Engineering 201
Introduction
Structure
Properties
Performance
Titanium alloys are used in aircraft, armor plating, naval ships, spacecraft, and missiles
Used for a variety of components including critical structural parts, fire walls, landing gear, exhaust ducts (helicopters), and hydraulic systems.
About two thirds of all titanium metal produced is used in aircraft engines and frames
50% of all alloys used in aircraft applications.
It has a chemical composition of 6% aluminum, 4% vanadium, 0.25% (maximum) iron, 0.2% (maximum) oxygen, and the remainder titanium.
The main types of microstructure:
Lamellar-formed after slow cooling
when deformation or heat treatment
takes place at a temperature in the
single-phase consisting of colonies of
hcp α-phase lamellae within large
bcc β-phase grains of several hundred microns
in diameter
2. Equiaxed – formed after
deformation in the two-phase
α+β field. It has better balance of strength
and ductility at room temperature
and fatigue properties which
depend noticeably on the
crystallographic texture of
the hcp α-phase.
Titanium is strong, light, and rustproof.
Similar to aluminum, but stronger and heavier.
Resists corrosion
Resists attack by strong acids and alkalis. It's relatively hard and brittle when it's cold and you have to heat it up to work it into shape or draw it into wires.
Various titanium materials are used for aircraft, each material selected according to use. Commercially pure titanium is used for airframes where formability is considered important
titanium alloys are used for engines where heat resistance and strength are considered important.
Lamellar
Equiaxed
Ces Edupack Statistics
Processing
Ti 6Al-4V wrought products are typically used in either a mill annealed or solution treated and aged condition.
Rapid quenching following solution treatment – maximizes alpha martensite and the aging response.
Other heat treatments used on Ti 6Al-4V include stress relieving for formed or welded parts, and beta annealing, which is used for improving damage tolerance.
Intermediate and final annealing- in a vacuum or inert gas atmosphere to avoid alpha case formation and the associated material loss.
Vacuum annealing- removes excess hydrogen pickup, a process known as vacuum degassing.
References
Pederson, Robert. "Prediction of Microstructure During High Temperature Forming of Ti-6Al-4V Alloy." Transactions of Materials Processing 12.4 (2003): Web.
Inagaki, Ikuhiro. "Titanium in the Aircraft Industry." Aircraft Eng & Aerospace Tech Aircraft Engineering and Aerospace Technology 29.4 (1957):
"The Most Remarkable Airplane of the 20th Century"" Signal v. Noise by Basecamp. Titanium Processing Center, 8 Apr Web. 25 Apr
Callister, William D., Jr., and David G. Rethwisch. "Chapter 11." Materials Science and Engineering an Introduction. Eighth ed. N.p.: Wiley John Wiley &Sons,Inc, 2010.(Table)
CES Edupack
Contact Information
Sahithi Chatradi