Most brittle fractures occur at temperatures?

Most brittle fractures occur at temperatures?

• A. At room temperature
• B. Below the impact transition temperature
• C. At high operating temperatures
• D. In high humidity

Answer: (B)

Brittle fracture is most likely when the metal is below its ductile-to-brittle transition temperature, where toughness drops and little plastic deformation accompanies fracture. In this low-temperature regime, the material can’t absorb much energy before cracking, so cracks propagate rapidly in a brittle manner. The impact transition temperature is the temperature where the material shifts from tough and ductile behavior to brittle behavior, often determined with Charpy-type impact tests. Therefore, many brittle fractures occur when service temperatures fall below this transition point. At room or higher temperatures, metals tend to be in the ductile regime and resist brittle fracture, and humidity doesn’t directly drive the fracture mode.

Brittle fracture is most likely when the metal is below its ductile-to-brittle transition temperature, where toughness drops and little plastic deformation accompanies fracture. In this low-temperature regime, the material can’t absorb much energy before cracking, so cracks propagate rapidly in a brittle manner. The impact transition temperature is the temperature where the material shifts from tough and ductile behavior to brittle behavior, often determined with Charpy-type impact tests. Therefore, many brittle fractures occur when service temperatures fall below this transition point. At room or higher temperatures, metals tend to be in the ductile regime and resist brittle fracture, and humidity doesn’t directly drive the fracture mode.