Nov 19 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Forging
Hot Working
Cold Working
Annealing
Applications
Introduction
Super alloys are also called high performance alloys. They have the capacity to function under very high temperatures and severe mechanical stress, and also where high surface stability is required. They have good creep and oxidation resistance. Super alloys contain many elements in a variety of combinations so as to achieve the desired result. Strengthening of super alloys is performed by solid-solution hardening, work hardening, and precipitation hardening methods.
There are three types of alloys, namely cobalt-base, nickel-base, and iron-base. All of these can be used at temperatures above 540°C (1000°F). Super alloy AL 200™ is a commercially pure (99%) wrought nickel alloy type. However it does contain some other elements amounting to less than 1%.
The following datasheet will provide more details about super alloy AL 200™.
Chemical Composition
The following table shows the chemical composition of super alloy AL 200™.
|
Element |
Content (%) |
|
Nickel, Ni |
99.8 |
|
Carbon, C |
≤ 0.15 |
|
Silicon, Si |
0.05 |
|
Iron, Fe |
0.05 |
|
Copper, Cu |
0.02 |
|
Manganese, Mn |
0.02 |
|
Sulfur, S |
0.002 |
Physical Properties
The physical properties of super alloy AL 200™ are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
8.90 g/cm³ |
0.322 lb/in³ |
|
Melting point |
1440°C |
2625°F |
Mechanical Properties
The mechanical properties of super alloy AL 200™ are provided below.
|
Properties |
Metric |
Imperial |
|
Tensile strength (typical annealed) |
462 MPa |
67000 psi |
|
Yield strength (@strain 0.200%, typical annealed) |
148 MPa |
21500 psi |
|
Elastic modulus |
207 GPa |
30000 ksi |
|
Shear modulus |
81 GPa |
11700 ksi |
|
Poisson’s ratio |
0.31 |
0.31 |
|
Elongation at break (typical in 2", annealed) |
47% |
47% |
|
Hardness, Rockwell B (typical annealed) |
45 |
45 |
Thermal Properties
The thermal properties of super alloy AL 200™ are given below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@27-93°C/80.6-199°F) |
13.3 µm/m°C |
7.39 µin/in°F |
|
Thermal conductivity (@100°C/212°F) |
67.1 W/mK |
466 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to super alloy AL 200™ are provided below:
-
ASTM A240
-
ASTM A479
-
ASTM A789
-
ASTM A790
-
ASTM A815
Fabrication and Heat Treatment
Machinability
Super alloy AL 200™ is soft and ‘gummy’, thus it is machinable by conventional methods using high-speed tools. It is recommended that high positive rake angle should be maintained while machining.
Forming
Super alloy AL 200™ can be formed using conventional methods. However it requires more force to form.
Welding
Super alloy AL 200™ is weldable using all the conventional methods. It is however suitable to use the shielded metal-arc, gas tungsten-arc and gas metal-arc welding methods. Welding should be performed using nickel filler wire or electrodes.
Forging
Forging of super alloy AL 200™ should be performed at 1232-927°C (2250-1700°F).
Hot Working
Hot working can be performed in the range of 1204-649°C (2200-1200°F).
Cold Working
Super alloy AL 200™ can be cold worked with standard tooling. It is better to use higher power as the nickel-base contains more elastic limit than steel and thus is not easy to deform.
Annealing
Super alloy AL 200™ can be annealed at 815°C (1500°F). It can also be performed between 926 to 704°C (1700 to 1300°F) based on the degree of cold working and time at temperature
Applications
Super alloy AL 200™ is used in electronic parts, and applications e.g. handling alkaline solutions and foods, that need resistance to corrosion