TENSILE TESTING OF BRITTLE

MATERIAL

Faculty of dentistry Alexandria university

Mohamed hamdy fawzyMohamed Adel Abdulla

Mohamed Adel NasserMohamed said romia

By:

Mohamed assume Mohamed

Why glass break ?

Glass is brittle material

What is brittle material mean ?

Brittleness :

Tendency of a material to fracture or fail upon the application of a relatively small amount of force , impact or shock .

SIMILARLY,a variety of brittle restorative material , including dental amalgam ,cements , ceramic material , plaster and stone .

• Note:In many instances the material is much weaker in tension than in compression which may contribute to failure of the material in service .

So,Brittle material must be gripped with caution ,and any stress concentrations at the grips can lead to premature fracture .

Tensile test of brittle material

An alternative method of testing brittle material , in which the ultimate tensile strength of a brittle material is determined through compressive testing .

The method is described as the diametral compression test for tension , Brazilian testOr indirect tensile .

Stress-strain curve :

Tensile strength :

HOW CAN BRITTLE MATERIALBE USEFUL IN DENTISTRY

Although ,This material are weak but have some special properties that is not found in other material .

Dental ceramics ,

Are characterized by their refractory nature High hardness and chemical inertness .

But,

With eating Hard material

Actually,

So ,What we can do to get more nature appearance as soon as great resistance to fracture ??

Veneer

The most advanced research in dentistry shown in micro-structure Of veneer proved that: Its compliance with teeth

Not surprising to see many of discoveries and developments in this area

اال ) العلم من اوتيتم وما.......(قليال

ANY QUESTION ?