Alloy 903 UNS N19903: Properties and Applications

# Alloy 903 UNS N19903: Properties and Applications

## Introduction to Alloy 903 UNS N19903

Alloy 903, also known as UNS N19903, is a nickel-iron-cobalt superalloy known for its excellent mechanical properties and resistance to high temperatures. This alloy is widely used in aerospace, power generation, and other industries where high strength and durability are required.

## Chemical Composition

The chemical composition of Alloy 903 plays a crucial role in its performance. Below is a breakdown of its primary elements:

– Nickel (Ni): 38-41%
– Iron (Fe): 15-20%
– Cobalt (Co): 15-20%
– Titanium (Ti): 1.3-1.8%
– Aluminum (Al): 0.7-1.2%
– Niobium (Nb): 2.7-3.3%

## Mechanical Properties

Alloy 903 exhibits outstanding mechanical properties, making it suitable for demanding applications:

– Tensile Strength: 1,240 MPa (180 ksi)
– Yield Strength: 1,035 MPa (150 ksi)
– Elongation: 12%
– Hardness: 35 HRC
– Density: 8.19 g/cm³

## Thermal Properties

The thermal properties of Alloy 903 contribute to its performance in high-temperature environments:

– Melting Point: 1,315°C (2,400°F)
– Thermal Conductivity: 11.4 W/m·K
– Coefficient of Thermal Expansion: 11.5 µm/m·°C (20-100°C)

## Applications of Alloy 903 UNS N19903

Alloy 903 is utilized in various industries due to its exceptional properties. Some common applications include:

### Aerospace Industry

In the aerospace sector, Alloy 903 is used for turbine engine components, such as disks, shafts, and blades. Its ability to withstand high temperatures and stresses makes it ideal for these critical parts.

### Power Generation

The alloy is also employed in power generation equipment, including gas turbines and steam turbines. Its resistance to creep and thermal fatigue ensures long-term reliability in these applications.

### Oil and Gas

Alloy 903 is used in downhole tools and other equipment in the oil and gas industry. Its corrosion resistance and high strength make it suitable for harsh environments.

## Advantages of Alloy 903

Alloy 903 offers several advantages over other superalloys:

– High strength at elevated temperatures
– Excellent fatigue resistance
– Good corrosion resistance
– Superior creep resistance
– Dimensional stability

## Conclusion

Alloy 903 UNS N19903 is a versatile superalloy with exceptional mechanical and thermal properties. Its applications span across aerospace, power generation, and oil and gas industries, where performance under extreme conditions is paramount. Understanding its properties and benefits can help in selecting the right material for demanding applications.