Engineering Materials
Ductile cast iron

Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
Is produced by annealing process. It is soft, tough and easily machined metal
Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

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Engineering Materials
Cobalt in steel

Improves cutting ability and reduce hardenability
Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties
Improves wear resistance, cutting ability and toughness
Gives ductility, toughness, tensile strength and anti corrosion property

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Engineering Materials
The unit cells

Have the same orientation and their similar faces are parallel
May be defined as the smallest parallelepiped which could be transposed in three coordinate directions to build up the space lattice
Contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal
All of these

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