Jul 25 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Heat Treatment
Applications
Introduction
Super alloys possess superior resistance to creep, good surface stability, and good corrosion and oxidation resistance. They were developed mainly to provide high performance at very high temperatures.
Super alloy Nibryl 360 is also known as nickel berrylium alloy 360. It is a precipitation hardening nickel based alloy that provides a number of strength, ductility and hardness combinations along with excellent corrosion resistance and unique resistance to galling.
The following sections will discuss in detail about super alloy Nibryl 360.
Chemical Composition
The chemical composition of Nibryl 360 is outlined in the following table.
|
Element |
Content (%) |
|
Nickel, Ni |
97.5 |
|
Beryllium, Be |
1.85 - 2.05 |
|
Titanium, Ti |
0.40 - 0.60 |
Physical Properties
The physical properties of Nibryl 360 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
8.28 g/cm3 |
0.299 lb/in3 |
|
Melting point |
1196 - 1330°C |
2185 - 2430°F |
Mechanical Properties
The following table shows mechanical properties of Nibryl 360.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
≥ 760 MPa |
≥ 110000 psi |
|
Yield strength |
≥ 345 MPA |
≥ 50000 psi |
|
Elastic modulus |
207 MPa |
30000 ksi |
|
Elongation at break |
≥ 45 % |
≥ 45 % |
Thermal Properties
The thermal properties of Nibryl 360 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal conductivity |
48 W/mK |
333 BTU in/hr.ft².°F |
|
Thermal expansion co-efficient (@20-200°C/68-392°F) |
14 µm/m°C |
7.78 µin/in°F |
Fabrication and Heat Treatment
Machinability
Nibryl 360 can be machined using all the traditional processes. Machining characteristics depend upon the temper of the material. It is recommended that cutting fluids appropriate for nickel alloys and stainless steels should be used. It is important to take precautions while grinding or performing any process that produces fine airborne particles as both beryllium and nickel particles are certified as health and safety hazards.
Forming
Nibryl 360 can be cold formed in the same manner as nickel in the annealed condition.
Heat Treatment
Nibryl 360 can be precipitation hardened or aged at temperatures of more than 371°C (700°F) and below 704°C (1300°F). Precipitation hardening helps to enhance strength and decrease ductility. When exposure time and temperature are well controlled, strength and ductility of annealed Nibryl 360 can be changed to match design requirements.
Applications
Nibryl 360 is chiefly used in the following application:
-
Valves
-
Glass molds
-
Pump parts
-
Permanent casting molds.