GB/T 39682-2020 in English

Technical Background of the Standard

With the development of cutting-edge fields such as aerospace engines (operating temperature ≥1600℃) and nuclear reactors (radiation-resistant ceramics), the traditional room temperature elastic modulus test method can no longer meet the needs. This standard innovatively proposes the gap ring relative method to solve the problem of system deformation interference in ultra-high temperature environments, and the test accuracy is improved by 40% compared with traditional methods.

Core Test Principles

Key instrument requirements

• Testing machine: Meet GB/T 16491 Level 1 accuracy, displacement resolution ≤1μm
• Heating furnace: Temperature control accuracy of ±15℃ above 1500℃, using three-zone independent temperature control
• Temperature measurement system: Infrared thermometer (ASTM E1256 standard) must be used when ≥1500℃

Sample preparation specifications

Typical sample parameters: outer diameter 15±1mm, inner diameter 12.5±1mm, notch height 6.25±0.5mm (0.5r). Surface roughness must be ≤0.2μm, parallelism deviation <0.02mm. It is recommended to use diamond wire cutting for alumina ceramic samples.

Implementation suggestions

1. During vacuum testing, first evacuate to 0.1Pa and then fill with high-purity argon (99.999%)
2. For tests above 1500℃, use tungsten-rhenium thermocouple with infrared calibration
3. The data acquisition frequency is recommended to be ≥10Hz, and the load increment is 30-40% of the breaking load