Jul 8 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Annealing
Forging
Hot Working
Cold Working
Applications
Introduction
Titanium alloys are metals containing a combination of titanium and other chemical elements. They are lightweight and corrosion resistant. Grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy is a beta wrought alloy. This alloy has good ductility and high strength.
The following sections will discuss in detail about grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy.
Chemical Composition
The chemical composition of grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy is outlined in the following table.
|
Element |
Content (%) |
|
Titanium, Ti |
75 |
|
Vanadium, V |
8 |
|
Chromium, Cr |
6 |
|
Zirconium, Zr |
4 |
|
Molybdenum, Mo |
4 |
|
Aluminum, Al |
3 |
|
Iron, Fe |
≤ 0.30 |
|
Oxygen, O |
≤ 0.14 |
|
Carbon, C |
≤ 0.050 |
|
Nitrogen, N |
≤ 0.030 |
Physical Properties
The physical properties of grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
4.82 g/cm3 |
0.174 lb/in3 |
|
Melting point |
1555 - 1650°C |
2831 - 3000°F |
Mechanical Properties
The following table shows mechanical properties of grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1240 MPa |
180000 psi |
|
Yield strength |
1170 MPa |
170000 psi |
|
Poisson’s ratio |
0.33 |
0.33 |
|
Elastic modulus |
104 GPa |
15100 ksi |
|
Shear modulus |
40 GPa |
5800 ksi |
|
Elongation at break |
7% |
7% |
|
Hardness, Brinell |
351 |
351 |
|
Hardness, Knoop |
382 |
382 |
|
Hardness, Rockwell C |
38 |
38 |
|
Hardness, Vickers |
367 |
367 |
Thermal Properties
The thermal properties of grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@0.000-100°C/32-212°F) |
8.30 µm/m°C |
4.61 µin/in°F |
|
Thermal conductivity |
6.20 W/mK |
43.0 BTU in/hr.ft².°F |
Fabrication and Heat Treatment
Machinability
Although tough, grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy can be machined using the right quantity of coolant flow, slow speeds and high feed rates. High-speed tools should be used for tooling this alloy and the recommended tool types are tungsten carbide designations C1-C4 or cobalt based.
Forming
Grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy can be hot or cold formed.
Annealing
Annealing of this material can be performed by heating to 704°C (1300°F), and holding for 2 h, which is followed by air cooling. In the case of intermediate stress relieving, the material should be heated to 482-538°C (900-1000°F) and held for 45 min.
Forging
Rough forging can be performed at 900°C (1650°F) and completed at 843°C (1550°F).
Hot Working
Hot working enhances the overall ductility of the material.
Cold Working
Cold working features of this material is same as that of austenitic stainless steel. Post-work annealing is recommended to re-attain favorable performance properties.
Applications
Grade 19 Ti 3Al 8V 6Cr 4Zr 4Mo alloy is used in the following application areas:
-
In tubulars in oil and gas wells
-
Fasteners
-
Torsion bars
-
Springs
-
Foil.