What is the difference between ductile and brittle failure?

Ductile failure and brittle failure are two distinct modes of material failure, and understanding their differences is crucial for material selection and structural design.

Ductile failure is characterized by significant plastic deformation before fracture occurs. This means that when a ductile material is subjected to stress, it will deform appreciably, allowing for energy absorption and redistribution of stress. This deformation is often visible, and it provides warning signs prior to failure, enabling preventive measures to be taken.

On the other hand, brittle failure occurs with little or no plastic deformation. It is typically sudden and catastrophic, with the material fracturing almost instantly under stress, often without any noticeable deformation beforehand. This behavior is typical in materials that are strong but lack the ability to deform plastically, resulting in a rapid fracture that can lead to unexpected structural failures.

The chosen option accurately describes this distinction, emphasizing the role of plastic deformation in ductile failure versus the lack of it in brittle failure. This understanding is essential when evaluating materials for applications where failure modes can impact safety and performance.