Molybdenum Alloy

TZM Alloy:

Composition & Mechanism: Centered on carbide precipitation strengthening. Trace amounts of Ti and Zr react with C to form nanoscale TiC and ZrC particles, which can effectively pin dislocations and grain boundaries, hindering deformation and grain growth at high temperatures.

Performance Characteristics:

• High-temperature strength: In the range of 1200–1500℃, its strength is over 1.5 times that of pure molybdenum.

• High recrystallization temperature: Approximately 1400℃, enabling it to maintain an unrecrystallized, strong and tough state at higher temperatures.

• Good thermal conductivity and thermal shock resistance.

• Application Scenarios: Thanks to its excellent strength, creep resistance, workability and relatively controllable cost, it has become the most widely used molybdenum-based structural material.

• Examples: Throat liners and gas rudders of rocket engines, high-temperature hot pressing/extrusion dies, divertor target plates of nuclear fusion devices.

Molybdenum-Lanthanum Alloy: The "Expert" in Recrystallization Resistance

Composition & Mechanism: Belongs to rare earth oxide dispersion strengthening. Ultra-fine La₂O₃ particles are uniformly dispersed in the molybdenum matrix, exerting a strong pinning effect on grain boundaries.

Performance Characteristics:

• Ultra-high recrystallization temperature: Up to 1800℃ or above, far exceeding that of other alloys.

• Unique recrystallized structure: After recrystallization, interlocking swallowtail-shaped grown grains are formed, avoiding brittle intergranular fracture and maintaining good ductility even after high-temperature service.

• Excellent electron emission performance.

• Application Scenarios: Its core advantage lies in dimensional stability and ductility retention after long-term high-temperature service.

• Examples: Heating elements and heat shields of high-temperature vacuum furnaces, thermal field components of sapphire crystal growth furnaces, electrodes of microwave tubes.

MHC Alloy: The "King" of High-Temperature Strength

Composition & Mechanism: A high-strength upgraded version of TZM. Hf (hafnium) is used to replace Ti/Zr, forming a more stable and high-temperature-resistant HfC precipitation phase.

Performance Characteristics:

• Unmatched extreme high-temperature strength and creep resistance among all molybdenum alloys, with distinct advantages especially above 1500℃.

• Recrystallization temperature is equivalent to or slightly higher than that of TZM.

• Disadvantages: Hf has high activity, requiring stricter process control; it has poor workability and extremely high cost.

• Application Scenarios: For applications with extreme requirements for high-temperature strength where cost is not the primary consideration.

• Examples: Key components of next-generation high thrust-to-weight ratio rocket engines, structural parts of ultra-high-temperature experimental devices.

Molybdenum-Rhenium Alloy: The "Wonder" of Low-Temperature Ductility

Composition & Mechanism: Relies on solid solution strengthening. High-content Re atoms dissolve into the molybdenum lattice, significantly altering its electronic structure and dislocation movement characteristics.

Performance Characteristics:

• Special ductility enhancement: Can greatly reduce the ductile-brittle transition temperature of molybdenum, enabling the alloy to maintain good ductility even at room temperature or low temperatures and facilitating cold working.

• Significantly improves the ductility of welded joints, solving the problem of weld cracking in molybdenum welding.

• High strength and high electrical resistivity.

• Critical disadvantage: Re is a rare and precious metal with an extremely high price, which severely limits its application.

• Application Scenarios: For cutting-edge fields with extreme requirements for ductility, reliability and weldability.

• Examples: Bellows of satellite attitude control thrusters, core components of space probes, high-reliability components of space nuclear reactors, special electronic devices.