Thermomechanical testing environment equipment classification

2017-06-01

Environmental equipment in temperature mechanics testing can be divided according to the operating temperature, including ultra-high temperature vacuum test system, high temperature vacuum test system, high temperature (atmospheric) test system, high temperature test chamber, high and low temperature test chamber, liquid nitrogen immersion test device, liquid helium Refrigeration ultra-low temperature test system.

1. Ultra-high temperature vacuum system

It is mostly used for high temperature mechanical tests in the range of 1700℃-3000℃. The mechanical properties within this temperature range are limited to the heating body material and fixture material, and can only be completed in a vacuum environment.

There are a variety of heating methods to choose from in a vacuum environment: electric heating, graphite heating element heating, W alloy heating element heating, Mo alloy heating element heating, etc.

Clamp materials include: graphite, W alloy, Mo alloy, C-C composite materials, etc.

2. High temperature vacuum testing equipment

For easily oxidized materials, even in low-temperature tests, they are required to be carried out in a vacuum or inert gas atmosphere. The test temperature is usually between 400°C and 1600°C. Choose FeCrAl resistance wire, metal Ta wire, W wire, Mo Wire is used as the heating element, and stainless steel, high-temperature alloy, and Mo alloy are selected to make the tooling fixture.

3. High temperature (atmospheric) test system

The temperature range of this type of high-temperature furnace is 500℃-1800℃. The test is conducted in an aerobic environment. The heating element uses FeCrAl resistance wire, silicon carbon rod, and silicon molybdenum rod. It should be noted that domestic silicon molybdenum rod can only grow below 1600℃. Time working, the 1800 type and 1900 type silicon molybdenum rod imported from Sweden Mountain can stably work at 1700°C and 1800°C respectively, but the price is expensive and the supplier does not provide quality guarantee.

The material of high-temperature fixtures is relatively easy to choose when it is below 1030℃. K3 and K465 can meet the requirements. At 1050-1200℃, directional casting alloy DZ22 can be selected to meet the usage requirements. When the DZ22 alloy fixture is used at extreme temperatures, its service life No more than 3000 hours.

At present, DD alloy has appeared in the civilian market and has higher high-temperature strength and oxidation resistance. However, it is difficult to obtain, difficult to process, has certain length restrictions, and is extremely expensive to process.

For temperatures exceeding 1200°C, aluminum oxide, silicon nitride, and silicon carbide can be selected as fixture materials. Ceramic materials are easily brittle and difficult to process. With the advancement of ceramic firing technology, they can still be fired very precisely. However, domestic ceramic materials can only work below 1600°C.

At present, our company's high-temperature ceramic fixtures can still meet high-temperature strength requirements in an environment of 1700°C. They have excellent oxidation resistance and can still have a relatively long service life.

4. High temperature test chamber

In environments below 500°C, metal-lined box-type electric furnaces can be used. The advantage is that they use hot air circulation and have more precise temperature uniformity.

5. High and low temperature test chamber

For non-metallic materials, such as rubber, plastic, resin, etc., it is often necessary to conduct low-temperature tests at the same time as high-temperature tests. The high-low temperature test chamber can meet this requirement. The maximum working temperature