The Heat Deflection Temperature (HDT)
The Heat Deflection Temperature (HDT) test, also known as the Heat Distortion Temperature test, is a material testing method used to determine the temperature at which a plastic or polymer specimen deforms under a specified load. It is particularly important for assessing the ability of a material to retain its shape and structural integrity under elevated temperatures, which is crucial in various applications where temperature variations are expected.
During the HDT test, a sample of the material is subjected to a constant load while being heated at a controlled rate. As the temperature increases, the material gradually softens and begins to deform under the applied load. The HDT is the temperature at which a defined amount of deflection occurs, typically 0.25 mm (0.010 inches) or 0.5 mm (0.020 inches), depending on the testing standard.
The HDT test is significant in various industries, including plastics, automotive, aerospace, electronics, and more.
The basic principle of thermal conductivity testing involves creating a controlled temperature difference across a sample of the material and then measuring the resulting heat flow. The heat flow is typically measured in terms of heat transfer rate (Watts) per unit area (square meters) per unit temperature difference (Kelvin). This is often expressed using the formula:
Thermal Conductivity (λ) = Heat Transfer Rate (Q) × Thickness (d) / (Area (A) × Temperature Difference (ΔT))
Our Facility:
- Equipment Name: HDT Tester
- Mark/Model: International equipments
- Range: 25 deg to 300 deg C
- Test Standard: ASTM D 648
- ISO 75