Among many metal materials adapted to extreme working conditions, Tungsten and Molybdenum have occupied an irreplaceable strategic position in aerospace engineering thanks to their outstanding core properties such as high temperature resistance, creep resistance and dimensional stability.

With their unique material advantages, they are widely used in key parts of the aerospace field. With unique material advantages, both are widely used in key parts of the aerospace field.

Overview of Tungsten and Molybdenum 

What Are Refractory Metals

The greatest core advantage of refractory metals is that they can maintain good mechanical strength, structural integrity and chemical stability under extreme high temperature environment, and are not prone to softening, deformation or oxidation.

Tungsten and molybdenum are the two most representative materials in the refractory metal family. In aerospace engineering, tungsten and molybdenum can not be separated from the support of hot end parts of rocket engine, thermal protection system of spacecraft, or precision structure parts in vacuum environment.

Similarities and Differences

Tungsten and molybdenum as belong to two of refractory metal material, there are many common on core performance, but also because of its characteristics.

Both the common mainly embodied in three aspects: one is all can fit in the field of aerospace high temperature service environment; Second, creep deformation is not easy to happen, can continue to keep the structural strength; 3 it is in a vacuum, inert gas, such as environment, not easy oxidation reaction, adaptation of aerospace equipment complex service environment.

Both at the heart of the differences are mainly concentrated on the density, mechanical properties and processing difficulty: the density of tungsten (about 19.35 g/cm after) is much higher than molybdenum (about 10.28 g/cm after), and high temperature strength and hardness is better than that of molybdenum, more suitable for the density, hardness, have special requirements of the scene; Density of molybdenum is relatively modest, easy processing and molding

Key Properties for Aerospace

Extremely High Melting Point

Many key parts in aerospace, such as the nozzles of rocket engines, can even reach temperatures of more than 2000°C. Tungsten and molybdenum meet this core requirement, even at extreme temperatures above 2000°C; You can work steadily. Tungsten and molybdenum precisely meet this core demand, even in extremely high-temperature environments above 2000°C. It can also work stably.

Excellent Creep Resistance

The core components of aerospace equipment undergo slow plastic deformation under long-term high temperature and constant load. Both tungsten and molybdenum have excellent high temperature creep resistance, with minimal creep deformation under long-term high temperature loading Both tungsten and molybdenum possess outstanding high-temperature creep resistance properties, and the amount of creep deformation is extremely small under long-term high-temperature loads.

Low Coefficient

Precision structure parts of aerospace equipment, such as navigation system components, spacecraft docking mechanisms, engine precision parts, etc., will experience dramatic temperature changes during service.

Both tungsten and molybdenum have low thermal expansion coefficient, stable thermal expansion performance, and minimal deformation in the process of drastic temperature change

Stability in Vacuum

Spacecraft serve in space for a long time and are exposed to complex and extreme environments such as vacuum and strong radiation. This requires materials to have good vacuum stability and environmental adaptability, and be less prone to oxidation, volatilization or performance degradation.

Tungsten and molybdenum in the vacuum environment have excellent stability, not easy oxidation reaction, also won't material volatilize or performance degradation caused by vacuum environment, to maintain the structural integrity and long-term mechanical properties. In addition, both to radiation, such as extreme temperature environment also has a good adaptability.

Applications of Tungsten

High-Temperature Components

In rocket engine, the tungsten is often used for nozzle throat, combustion chamber wall, such as high temperature core, with its high melting point and high temperature hot strength, can effectively resist high temperature gas scour and corrosion, keep the parts stable structure, to ensure that the engine thrust output.

Aerospace Counterweights

In the field of aerospace, tungsten is widely used flight control system of counter weight, etc. For example, in the aircraft wings and tail part, by installing tungsten counterweight block, can adjust the aircraft's center of gravity, guarantee the stability of the flight. For instance, in the wings and tail sections of aircraft, by installing tungsten counterweights, the center of gravity of the aircraft can be adjusted to ensure the stability of the flight posture.

Thermal Protection

In the thermal protection system, tungsten is often used in the thermal protection panel of spacecraft re-entry into the atmosphere, the thermal shielding cover of rocket engine and other components. With its extremely high melting point and high temperature stability, it can effectively resist the erosion of high temperature heat flow, reduce heat transfer, and protect internal structures and components.

Common Tungsten Product Forms Used

Tungsten rods are mainly used as raw materials for high-temperature structural components such as rocket engine nozzles and turbine blades. Through subsequent precision processing, they are made into core components that meet the requirements. Tungsten plates are often used in thermal protection panels for spacecraft, etc. With their smooth surface and stable performance, they are suitable for the usage requirements of large-area structural components. Tungsten wire is used in high-temperature heating elements in the aerospace field, etc. With its slender and high-temperature resistant characteristics, it is suitable for the usage requirements of precision components

Applications of Molybdenum

High-Temperature Structure

Compared with tungsten, molybdenum has a lower density (about 10.28g/cm³) and a better strength-to-weight ratio. While ensuring high-temperature performance, it can effectively reduce the weight of components. Meanwhile, the processing performance of molybdenum is superior to that of tungsten. It is easy to be processed by rolling, forging, cutting, etc., and can be made into support components with complex structures.

Aerospace Engine 

In the engine combustion system, molybdenum is often used in the combustion chamber lining, flame cylinder, fuel nozzle and other components. With its excellent high temperature stability and dimensional stability, it can maintain the structure integrity in the middle and high temperature environment, not easy to deformation or oxidation, and has good corrosion resistance.

Vacuum Furnaces 

Molybdenum is widely used in vacuum furnace heating elements in aerospace manufacturing. In vacuum environment, molybdenum is not easy to oxidize, can work stably in high temperature environment for a long time, and has good thermal conductivity. In addition, molybdenum can bear the weight of trays and components, is not prone to deformation, has a long service life, and can reduce the maintenance cost of vacuum furnaces

Typical Uses 

Molybdenum plates are mainly used for components such as the combustion chamber linings of aerospace engines, and are suitable for the use requirements of large-area structural parts and heating components; molybdenum rods are often used in high-temperature structural supports of engines, meeting the requirements of structural design; molybdenum tubes are used in the fuel pipelines of aerospace engines, and with their excellent high-temperature resistance, corrosion resistance and sealing performance, they can stably transport fuel and other substances at medium-high temperatures, ensuring the normal operation of the engine and the heat exchange system.

Tungsten vs. Molybdenum

Material Selection

In the field of aerospace, tungsten and molybdenum material core depends on the specific needs of the project scene, and the density, melting point, processing performance, the difference of the key engineering measures such as cost, determine the application boundary and trade-offs logic.

1. Density: high density is the core advantage of tungsten for counterweight and radiation shielding, but it also leads to the large weight of its components; Molybdenum has a moderate density and a better strength-to-weight ratio, making it more suitable for high-temperature structural components with lightweight requirements.
2. Melting point: high temperature thermal strength and creep resistance is also better than molybdenum, more suitable for extreme high temperature conditions; Molybdenum is suitable for medium and high temperature conditions below 1500°C, which can meet the use needs of most high temperature components in aerospace.
3. Processing performance: molybdenum is easy to be rolled, forged, cutting, welding and other processing, can be made into complex structure parts, processing cost is relatively low; Tungsten to the use of special processing technology, processing is difficult, long cycle, high cost.
4. Cost: molybdenum raw material reserves are relatively rich, processing difficulty is low, so raw materials and processing costs are lower than tungsten; Tungsten reserves scarce raw materials, processing technology is complex, the overall procurement cost is far higher than that of molybdenum, suitable for low sensitivity to high performance requirements, cost at the core of the key components.

Choose Manufacturer, Not Supplier

As the global industrial transfer to China, China has become the core of titanium and tungsten products supply base. Combat as China's leading titanium and tungsten manufacturers, with years of industry experience and technology accumulation, for the global customers with high quality and customized titanium tungsten products and one-stop solution.

Combat’s Product Capabilities

Available Forms

Combat can provide a full range of titanium and tungsten products, covering a variety of forms, meet the demand of different industries, different conditions of purchase:

Titanium/Tungsten Rod, Tungsten Sheet&Plate, Wire, Tube, Machined Parts & OEM Components, We can provide customized size, specification and precision according to customer's requirements.

Manufacturing Advantages

1. Strong customization ability: according to the customer's project needs, customized titanium tungsten products of different sizes, specifications, performance, suitable for complex working conditions and personalized application scenarios.
2. Strict tolerance and quality control: the use of advanced production equipment and testing instruments, establish a perfect quality control system, strict control of product tolerance, strength, hardness, corrosion resistance and other indicators.
3. Support OEM/ODM projects: Have rich experience in OEM/ODM services, and can cooperate with customers to complete the whole process of product design, development, production and delivery.

Conclusion

Tungsten and molybdenum, as typical refractory metals, occupy an irreplaceable strategic position in aerospace industry. For aerospace engineers and purchasers, it is necessary to select the most suitable material based on the working temperature, weight requirements, processing difficulty and cost budget of the specific project. At the same time, choose a reliable and professional supplier of tungsten molybdenum, is the key to the success of the aerospace project.