What are the differences between Pure molybdenum plates, MoLa alloy plates and TZM alloy plates?

The main differences between pure molybdenum plates, molybdenum-lanthanum alloy plates, and TZM molybdenum alloy plates lie in their high-temperature performance and applicable scenarios: pure molybdenum plates are low in cost and suitable for non-load-bearing components below 1100°C; TZM alloy plates offer better high-temperature strength and creep resistance, suitable for high-stress environments of 1200-1400°C; molybdenum-lanthanum alloy plates have the highest recrystallization temperature and creep resistance, specifically designed for long-term service at ultra-high temperatures above 1400°C.

Pure molybdenum plates are renowned for their high melting point (2610°C), excellent high-temperature strength, creep resistance, and good thermal and electrical conductivity, making them a fundamental material in the electronics industry, aerospace, and other fields.

However, their recrystallization temperature is relatively low (approximately 1000°C). Pure molybdenum plates possess a certain strength at room temperature, but as the temperature rises (above 1000°C), the strength decreases sharply due to recrystallization. After recrystallization, impurities tend to accumulate at the grain boundaries, and the grains become coarse, leading to a decline in both high-temperature and room-temperature performance. Pure molybdenum plates become brittle and difficult to bend or stamp at room temperature. This limits its application in extreme environments.

Application Areas:

Pure molybdenum plates are suitable for low-temperature (<1100°C) or non-load-bearing applications, such as ordinary sintering boats, supports, electron tube auxiliary components, high-temperature furnace hot zones, and photovoltaic modules.

Molybdenum-lanthanum alloys plates are strengthened by doping a molybdenum matrix with 0.5%–5.0% dispersed lanthanum trioxide (La₂O₃ ) particles, a type of oxide dispersion strengthening.

La₂O₃ particles effectively pin grain boundaries, strongly inhibiting grain growth at high temperatures, thus significantly increasing the recrystallization temperature and greatly improving the material's high-temperature stability.

Performance Characteristics:

- High Recrystallization Temperature: 1400℃–1500℃, far higher than pure molybdenum; even after high-temperature heating, it maintains a fine, fibrous grain structure, avoiding embrittlement.

- Room Temperature Plasticity: Excellent. Even in the recrystallized state, it exhibits better ductility than pure molybdenum and TZM, facilitating secondary processing such as stamping and bending.

- High-temperature strength: Superior to pure molybdenum, but generally lower absolute strength than TZM alloy.

- Excellent creep resistance: Maintains structural stability even at 1800°C.

Application Areas:

Suitable for long-term service at ultra-high temperatures (>1400°C), such as glass melting electrodes, glass stirring rods, high-temperature furnace heating elements (above 1700°C), vacuum furnace heat shields, sintering boats, material support frames, evaporator coils, and other high-temperature components.

TZM molybdenum alloy plate utilizes a complex strengthening mechanism through the addition of Ti, Zr, and C. Its overall performance surpasses that of pure molybdenum and molybdenum-lanthanum alloys. With its unparalleled high-temperature strength and creep resistance, it is primarily used for the most demanding high-temperature structural components.

Performance Characteristics:

- High-Temperature Strength and Hardness: Best among the three. From room temperature to over 1400°C, its strength and hardness are significantly higher than pure molybdenum and molybdenum-lanthanum alloys.

- Recrystallization Temperature: Very high, with a recrystallization initiation temperature of 1150°C and a completion temperature of 1250°C, second only to molybdenum-lanthanum alloys.

- Creep Resistance: Best, ideal for components subjected to high-temperature, heavy loads.

- Room Temperature Plasticity: Relatively poor. Although better than recrystallized pure molybdenum, it is inherently brittle, making secondary processing (such as bending) difficult.

Applications:

TZM alloy plates are suitable for high-temperature (1200-1400°C) and high-stress environments, such as copper alloy die-casting molds, rocket nozzles, torpedo engine valve bodies, aerospace high-temperature structural components, electron tube cathodes and nuclear energy equipment components, high-temperature furnace structural components, hot isostatic pressing and hot pressing sintering molds, and high-temperature metal rolling and extrusion molds.

In summary, pure molybdenum plates are suitable for conventional high-temperature environments, but recrystallization should be avoided; molybdenum-lanthanum alloys are suitable for long-term high-temperature stability applications, but the upper temperature limit needs to be controlled; TZM alloys offer the best overall performance and are the preferred choice for extreme high-temperature and mechanical load conditions. Selecting materials based on actual needs maximizes the balance between performance and economy.