Griffith attributed the discrepancy between the observed fracture strength of crystals and the theoretical cohesive strength to the presences of flaws in brittle materials. This theory is applicable only to perfectly brittle material such as glass, and cannot be used directly to metals. However, Griffith's ideas formed a base to understand the fracture in metals. Griffith proposed that a brittle [...]
In this article we will discuss about:- 1. Introduction to Fracture 2. Fundamentals of Fractures 3. Theoretical (Atomic) Fracture Strength of Brittle Material 4. Toughness 5. Prevention. Introduction to Fracture: The final stage of the tensile test is the process of fracture. Inspite of understanding of the behaviour of materials, service failures frequently occur. It is almost always an undesirable [...]
The following points highlight the two main types of fracture. The types are: 1. Ductile Fracture and Rupture 2. Brittle Fracture. Type # 1. Ductile Fracture and Rupture: A ductile fracture is characterized by extensive plastic deformation in the vicinity of an advancing crack. Ductile- fracture-surfaces have their own distinctive features on both macroscopic and microscopic levels. Fig. 15.3 illustrates [...]
"Fracture" is the Breaking of a Metal to Yield an Irregular Surface: The topography of the fractured surface is an important characteristics intimately connected with the crystalline form and in some cases it may give an indication of the purity of the metal. In a polycrystalline material there can be three distinct modes of fracture as given below: 1. Inter-granular [...]