High-temperature resistant molybdenum disilicide U-shaped silicon molybdenum rod

Molybdenum disilicide rods are resistance heating elements based on molybdenum disilicide. When sintered molybdenum disilicide products are heated to high temperatures in an oxidizing atmosphere, a dense quartz glass film forms on their surface. Molybdenum disilicide rods are resistant to high temperatures; in high-temperature atmospheres, a dense quartz protective layer forms on the surface of the element to prevent further oxidation. So, what issues might arise during the use of molybdenum disilicide rods?

1. Reduced Lifespan in Gas Environments

Using molybdenum disilicide rods in environments such as nitrogen or argon can significantly shorten their lifespan. This is because, in these atmospheres, the pre-applied film from the factory cannot catalyze the formation of a new oxide layer, leaving the rods unprotected and subject to continuous oxidation and thinning. This effect is particularly pronounced in intermittent furnaces with such atmospheres. Therefore, after a period of use in protective gases, it is necessary to perform an air burn to form an anti-oxidation film, thereby extending the lifespan of the molybdenum disilicide rods.

2. Brittle Fracture at Room Temperature

The resistance of molybdenum disilicide elements does not change with usage time, so new and old elements can be used together.

Thus, molybdenum disilicide elements possess excellent high-temperature oxidation resistance. However, like other ceramic products, their mechanical properties make them brittle materials that may crack at room temperature. Proper use and appropriate equipment can prevent this issue.

3. Oxidation Damage at Low Temperatures

Whether molybdenum disilicide rods can be used for long-term constant temperature operation at various temperatures primarily depends on whether they have been used in high-temperature environments before.

Typically, during equipment debugging, it is necessary to heat the rods to 1600°C and maintain that temperature to allow surface oxidation, forming a glass film that prevents further oxidation.