What characterizes a "cup and cone fracture"?

A "cup and cone fracture" is characterized by its distinctive shape, which features one side resembling a cone and the other side having a cup-like appearance. This type of fracture is typically seen in ductile materials and indicates a significant amount of plastic deformation prior to fracture. The cone and cup shapes form due to the way the material behaves when subjected to tensile stresses, with the material stretching and yielding at the center, resulting in a cone shape, while the surrounding material forms a cup shape as it pulls away.

The other characteristics do not accurately describe the nature of a cup and cone fracture. A smooth and even break would describe a brittle fracture, which lacks the features observed in a cup and cone scenario. Fractures that occur under high temperatures would often lead to different fracture types, such as those seen in creep failure, rather than a cup and cone structure. Lastly, a fracture with uniform thickness generally refers to more linear failures, which again contrasts with the uniquely asymmetrical forms seen in cup and cone fractures.