Question

The fracture occurred during the crack propagation along the grain boundaries is called

• A. Inter granular fracture
• B. Trans granular fracture
• C. Ductile fracture
• D. Brittle fracture

Hint:

Memorize the prefixes: Inter- means "between" (between the grains). Trans- means "across" (across the grains). This makes it easy to distinguish the two main fracture paths.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In polycrystalline materials (materials made of many crystals or 'grains'), a crack can propagate in two primary ways relative to the grain structure. The path of the crack provides important clues about the failure mechanism.

Step 2: Detailed Explanation:
Let's define the fracture paths:

• (A) Intergranular fracture: The crack propagates along the grain boundaries. The prefix "inter-" means "between". This type of fracture often occurs when the grain boundaries are weakened, for example, by segregation of impurities, corrosion, or at high temperatures where grain boundary sliding occurs. The fracture surface shows the facets of the individual grains.

• (B) Transgranular fracture: The crack propagates through or across the grains. The prefix "trans-" means "across". This is also known as cleavage fracture in brittle materials. The crack follows specific crystallographic planes within each grain.

• (C) Ductile fracture and

(D) Brittle fracture: These terms describe the extent of plastic deformation accompanying the fracture, not the path itself. An intergranular fracture is typically a brittle mode of failure, but the term "intergranular" is more specific about the crack path.
The question specifically asks for the name of the fracture that follows the grain boundaries. By definition, this is intergranular fracture.

Step 3: Final Answer:
A fracture that propagates along the grain boundaries is called an intergranular fracture.