Materials overview
Not many metals hold up at high temperature, and fewer still can be worked into thin sheet and wire. Molybdenum is in that rare position.
It has the highest melting point after tungsten, while being far ahead on machinability and thermal conductivity.
Its low thermal expansion means it stays aligned with ceramics and semiconductor chips when bonded to them as the temperature rises and falls. It holds its shape through long operation above 2,000℃ in vacuum and reducing atmospheres, which has made it the standard for heating elements and heat shields in high-temperature vacuum furnaces and semiconductor process equipment.
Key Property Values
These are the values engineers check first at the design stage. Actual delivery specifications follow the per-lot test report.
| Item | Value | Description |
|---|---|---|
| Melting point | 2615 °C | The highest of any practical metal after tungsten |
| Thermal conductivity W/m·K | 138 | About 9 times that of stainless steel |
| Density g/cm³ | 10.2 | About 53% of tungsten |
| Thermal expansion µm/m·K | 5.2 | Matched to AlN and alumina, at room temperature |
| Recommended atmosphere | Vacuum | Oxidizes above 600°C in air — a protective atmosphere is required |
| Supply grades | 4 | Pure Mo · La-Mo · TZM · MoCu |
Figures are representative values. The thermal expansion coefficient is taken from published literature and needs review before release.
Key Advantages
How these figures translate into advantages in actual processes.
Ultra-high melting point · high-temperature strength
In a high-temperature vacuum furnace it shows almost no creep deformation under its own weight and thermal load. Heating elements and support structures can be designed in the same material.
Corrosion resistance · chemical stability
It is barely attacked by molten glass, liquid metals or non-oxidizing acids. It does not become a contamination source even in chambers with reactive gas flowing.
Low thermal expansion · dimensional stability
At a CTE of 5.2 it is close to ceramics. Joints do not open up through repeated heating and cooling, which suits precision parts.
Supply Forms · Machining Options
| Form | Specification |
|---|---|
| Wire · Rod stock | Ø 0.015 – 3.17 mm |
| Sheet · Plate | t 0.05 – 50.0 mm |
| Rod · Bar | Ø 0.5 – 165 mm |
| Ribbon · Strip | t 0.015 – 0.762 mm Width 1 – 360 mm |
Custom Machining Capability
- Cutting to drawing dimensions · CNC / MCT machining
- Wire EDM · laser machining · welded assemblies
- Forming (bending · deep drawing) and surface treatment
- The same tolerances from a single prototype to full production
Related Products · Applications
AlN heater element
Patterned heating element embedded in ceramic. Matching thermal expansion is the critical point
Vacuum furnace heat shield
Multi-layer thin sheet that blocks radiant heat loss
Sputtering target
Pure Mo target for display thin-film deposition
Semiconductor equipment parts
Hot zone jigs and susceptor supports inside the chamber
Electrodes · Crucibles
High-temperature vessels and electrodes that react little with molten metal
Evaporation coils
Heating coils and boats for evaporation
