High-Melting-Point Material With Dimensional Stability
Tungsten has the highest melting point of all metals at 3,422 °C and combines high density with pronounced dimensional stability. Its low thermal expansion minimizes deformation during temperature fluctuations and ensures dimensional accuracy. The dense microstructure, along with its inherent resistance to radiation and corrosion, gives the material high mechanical strength and structural resilience.
Compared to tungsten-copper, pure tungsten provides significantly higher thermal resistance, but has lower thermal conductivity and reduced machinability.
Composition of Tungsten
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Tungsten
W
100%
Key Properties
Heat Resistance
With a melting point of 3,422 °C, tungsten has the highest of all metals. This makes it stable even at extreme temperatures and suitable for components exposed to continuous thermal stress. It is used in processes such as plasma spraying, arc furnaces, rocket propulsion systems, and vacuum or inert gas environments.
Density
With a density of 19.3 g/cm³, tungsten is one of the densest elements. This mass gives components superior inertia properties: flywheels run more smoothly, counterweights operate with greater precision, and radiation shielding is effective even at low wall thicknesses.
Electrical Conductivity
Tungsten retains about 30 percent of copper’s conductivity at elevated temperatures. Where other metals fail due to melting, tungsten remains conductive and operational. This is critical for high-temperature heating elements and filaments.
Dimensional Stability
Tungsten has a low coefficient of thermal expansion at just 4.5 × 10⁻⁶/K. It maintains its shape under rapid temperature shifts, which is essential for precision parts exposed to thermal stress.
Physical and Mechanical Properties
Property | Unit | Value |
|---|---|---|
Tensile strength (Rm) | MPa | 600–1200 |
Hardness (Vickers) | HV | min. 310 |
Electrical conductivity | MS/m | 18.5 |
Density at 20°C | g/cm³ | 19.3 |
Thermal conductivity | W/cm·K | 1.7 |
Elastic Modulus (E) | GPa | 410 |
Shear modulus (G) | GPa | 165 |
Specific heat capacity | J/kg·K | 140 |
Electrical resistivity | 10⁻⁶·Ω·m | 0.056 |
Boiling Point | °C | 5555 |
These figures represent minimum values, typical averages or defined tolerance ranges. If your application requires specific material characteristics such as defined thermal stability, increased mechanical strength or enhanced chemical resistance, we will develop a suitable variant in close cooperation with you. Get in touch to discuss your specifications.
Industrial Applications
Typical use cases for tungsten in industrial environments
Lighting Technology
Tungsten’s high melting point and efficient light emission make it suitable for heat-resistant components in lighting applications. It is primarily used as a filament in incandescent and halogen lamps.
Tool and Mechanical Engineering
In toolmaking, pure tungsten is primarily used for compact counterweights and flywheels where high inertia is required in limited space. It is also used in thermally stressed tool components that must maintain dimensional accuracy under significant temperature fluctuations.
Aerospace
Tungsten alloys are used in turbines, propulsion systems and rocket components. They withstand extreme temperatures and mechanical stresses while maintaining dimensional stability under dynamic conditions.
Medical Technology
High density, strong shielding properties and biocompatibility make tungsten a suitable material for precision instruments, radiation protection components, imaging systems and applications in nuclear medicine.
Manufacturing Process
The production of a tungsten rod involves multiple steps to achieve the desired material properties.
- 1Step 1
Raw material extraction and processing
The primary tungsten ores are scheelite (CaWO₄) and wolframite ((Fe,Mn)WO₄). These are processed through crushing, grinding and froth flotation to produce tungsten concentrates with up to 70% tungsten content.
- 2Step 2
Chemical refining
Tungsten trioxide (WO₃) is dissolved in sodium hydroxide or hydrochloric acid. After filtration to remove impurities, ammonia is added to precipitate ammonium paratungstate (APT), which is then crystallised and filtered.
- 3Step 3
Reduction of APT to tungsten trioxide
APT is reduced at around 500 °C, releasing ammonia and forming tungsten trioxide (WO₃). The released ammonia can be recovered and reused.
- 4Step 4
Reduction to tungsten powder
Tungsten trioxide is reduced in a hydrogen atmosphere at 800 to 1000 °C. The process takes place in several stages in dedicated reduction furnaces, producing fine tungsten powder.
- 5Step 5
Powder metallurgy
The resulting tungsten powder is processed by powder metallurgy. It is compacted under high pressure and sintered at elevated temperatures.
- 6Step 6
Compaction and sintering
The powder is pressed into molds and sintered at 2200 to 2500 °C. During sintering, the particles fuse to form a dense solid material.
- 7Step 7
Forging and rolling
Sintered tungsten rods are forged and/or hot-rolled at elevated temperatures. This improves material density and structural uniformity.
- 8Step 8
Grinding and polishing
After mechanical processing, the rods are ground and polished to achieve a smooth, precision surface finish.
- 9Step 9
Quality control
All process steps are subject to strict quality control to ensure the rods meet the required specifications.
- 10Step 10
Packaging and shipping
Finished tungsten rods are packed using protective materials to prevent transport damage.
This process ensures that tungsten components achieve the material properties required for industrial use. These include very high mechanical strength, reliable dimensional stability at elevated temperatures, and combined resistance to wear and thermal stress.
Talk to Our Material Specialists
In close cooperation with you, we analyse your requirements, provide comprehensive guidance and find the solution that fits your process best.
