What does the term 'brittle fracture' indicate in materials science?

The term 'brittle fracture' in materials science refers to a sudden failure of a material with minimal plastic deformation. This type of fracture occurs when a material fails to absorb energy before breaking, resulting in a clean break rather than a gradual deformation.

Brittle fractures typically happen in materials that have high hardness but low ductility, such as ceramics or some high-strength metals. Under stress, these materials do not undergo significant plastic deformation—they crack and break almost instantly when they reach their failure threshold. This behavior is crucial for engineers and designers to understand because it can lead to catastrophic failures in structures and components if not accurately predicted.

In contrast, the other options describe different failure mechanisms or states that do not align with the characteristics of brittle fracture. Understanding the distinction between brittle and ductile failure modes is essential for materials selection and ensuring the integrity of engineering applications.