Properties of Metals
Ductility is the property by which material can be stretched. Large deformations are thus possible in ductile materials before the absolute failure or rupture takes place. These materials have post-elastic strain [ Plastic strain] greater than 5%. Some of the examples are Mild steel, Aluminium, Copper, Manganese, Lead, Nickel, Brass, Bronze, etc.
Brittleness is the lack of ductility i.e, materials cannot be stretched, In brittle materials, fracture takes place immediately after elastic limit with a relatively smaller deformation, For the brittle materials fracture and ultimate points are the same and after proportional limit, very small strain is seen. Brittle materials have post elastic strain of less than 5%. Examples are cast iron, concrete, and glass.
It is that property of metal due to which a piece of metal can be converted into a thin sheet by pressing it. A malleable material possesses a high degree of plasticity. This property is of great use in operations like forging. hot rolling, drop (stamping), etc.
Hardness is resistance to scratch or abrasion.
There are two methods of hardness measurements:
1. Scratch hardness-commonly measured by Mohr's test
2. Indentation hardness (abrasion) measured by
- Brinell hardness method
- Rockwell hardness
- Vickers hardness
- Knoop hardness