Aug 6 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Fabrication and Heat Treatment
Machinability
Workability
Heat treatment
Annealing
Aging
Applications
Introduction
Grade Ti-4Al-3Mo-1V alloy is an alpha-beta sheet alloy that is a heat treatable. It provides excellent strength, creep and stability up to 482°C (900°F). This alloy does not corrode in salt or atmospheric environments.
The following sections will discuss in detail about grade Ti-4Al-3Mo-1V alloy.
Chemical Composition
The chemical composition of grade Ti-4Al-3Mo-1V alloy is outlined in the following table.
|
Element |
Content (%) |
|
Titanium, Ti |
92 |
|
Aluminum, Al |
4 |
|
Molybdenum, Mo |
3 |
|
Vanadium, V |
1 |
Physical Properties
The physical properties of grade Ti-4Al-3Mo-1V alloy are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
4.50 g/cm3 |
0.163 lb/in3 |
Mechanical Properties
The following table shows mechanical properties of grade Ti-4Al-3Mo-1V alloy.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1275 MPa |
184900 psi |
|
Yield strength |
1100 MPa |
160000 psi |
|
Shear strength |
950 MPa |
138000 psi |
|
Elongation at break |
3-5% |
3-5% |
Fabrication and Heat Treatment
Machinability
Grade Ti-4Al-3Mo-1V alloy is hard to machine but can be successfully done using rigid machine setups, slow speeds, high coolant flow, sharp tools and high feed rates. It is recommended that straight tungsten carbide grades and cobalt high-speed steels, and water-based or chemical cutting fluids should be used to achieve optimum performance.
Workability
Workability of grade Ti-4Al-3Mo-1V alloy is good. The following are some recommendation while working on this alloy:
-
Aged and solution-treated alloy is suitable for nominal forming
-
Annealed alloy should be used while performing extensive hot forming above 593°C (1100°F)
-
With solution-treated alloy, it is possible to achieve top formability and smallest bend radius
-
It is possible to bend, wrap and jog aged and solution-treated sheets at room temperature.
Heat treatment
For solution treatment of grade Ti-4Al-3Mo-1V alloy, it should be held at 871-899°C (1600- 1650°F) for 15 to 30 min, and then water quenched.
Annealing
Annealing of this material can be performed by heating to 704-760°C (1300-1400°F) for 30 min and then slowly air cooled. In case stress relieving is required, the material has to be heated to 482-593°C (900-1100°F) followed by air cooling.
Aging
Aging can be performed after solution treatment by reheating and holding at 496°C (925°F) for 6 to 12 h.
Applications
Grade Ti-4Al-3Mo-1V alloy is used in the following application areas:
-
In the aircraft industry for several components such as stiffeners, internal structures, and skins on airframes.