The document discusses different types of material failure including fracture, fatigue, and corrosion. It describes brittle fracture as occurring with rapid crack propagation and little plastic deformation, while ductile fracture absorbs more energy and involves successive stages. Griffith's theory of crack propagation is explained, where fine cracks in brittle materials grow and the material fractures at a certain stress value. Corrosion is defined as the destruction of metals by chemical reactions with the environment. Different types of corrosion are listed such as oxidation, degradation, radiation damage, and rusting. The presentation concludes with a brief mention of other materials like optical and thermal materials and nano-materials.

1. BABA SAHEB BHIMRAO AMBEDKAR UNIVERSITY
(A CENTRAL UNIVERSITY)
Material Science Presentation
Presented By : Abhishek Pandey
Abhishek Rathour
Pankaj
Anand Prasad

2. PERFORMANCE OF
MATERIALS
Fracture , Fatigue and
Corrosion

3. FRACTURE
Types of Fracture –
1. Ductile Fracture
2. Brittle Fracture

4. BRITTLE FRACTURE -
The Failure of a Material with rapid rate of crack propagation and
negligible plastics deformation is called “Brittle Fracture “ . Broken Pieces of Material can be
assembled togather to get unbroken shape and size .
Ductile Fracture -
In Ductile Fracture , a material absorbs large energy prior to
failure . Successive Stages in the mechanism of ductile fracture are, shown in Background
image .

5. GRIFFITH’S THEORY OF CRACK PROPAGATION
The Propagatioin of a Pre-existing crack in a brittle material has been
explained by Griffith . He assumes that there are too many fine elliptical
cracks in a brittle material . Consider one auch crack of 2L length
extending though the thickness t of the material as shown in background
image.
𝑈 = 𝛾 𝐴
Salient Features of Griffith Theory –
Surface Cracks on Materials are Twice as effective as the internal Cracks .
A Material Fractures at a certain Value of applied Stress.
A Scratch on the Surface is of the order of r ~ 0.1A or Less .

6. CORROSION
The Destruction of metals by chemical or electro-chemical
reactions with the environment is called as Corrosion . Freedom of Valence elctrons
and their conduction is responsible for corroison in metal .
Type of Corrosion -
1- Oxidation that occurs in metals at high temperatures .
2- Degration that takes places in polymers on reacting with oxygen .
3- Radiation damage that happens with materials in nuclear reactors .
4- Rusting that occurs in iron under atmospheric condition .

7. Thanks For Watching

8. OTHER MATERIAL ( OPTICAL AND THERMAL MATERALS , NANO-
MATERIALS )
By Optical Property we mean the response of the response of a
material