07-26-2014, 11:42 AM
Lead and Lead alloys
Lead was one of the first metals known to man. Probably the oldest lead artifact is a figure made about 3000 BC. All civilizations, beginning with the ancient Egyptians, Assyrians, and Babylonians, have used lead for many ornamental and structural purposes.
Lead's chemical symbol comes from the Latin word for waterworks, plumbum.
Many magnificent buildings erected in the 15th and 16th centuries still stand under their original lead roofs.
Grey colour
Very soft
Low melting point
Ductile and malleable
Very toxic
![[Image: lead.jpg]](http://www.frontdesk.co.in/big/cm/lead.jpg)
![[Image: lead1.jpg]](http://www.frontdesk.co.in/big/cm/lead1.jpg)
The properties of lead that make it useful in a wide variety of applications are density, malleability, lubricity, flexibility, electrical conductivity, and coefficient of thermal expansion, all of which are quite high; and elastic modulus, elastic limit, strength, hardness, and melting point, all of which are quite low. Lead also has good resistance to corrosion under a wide variety of conditions. Lead is easily alloyed with many other metals and casts with little difficulty.
The high density of lead (11.35 g/cm3, at room temperature) makes it very effective in shielding against x-rays and gamma radiation. The combination of high density, high limpness (low stiffness), and high damping capacity makes lead an excellent material for deadening sound and for isolating equipment and structures from mechanical vibrations.
Lead was one of the first metals known to man. Probably the oldest lead artifact is a figure made about 3000 BC. All civilizations, beginning with the ancient Egyptians, Assyrians, and Babylonians, have used lead for many ornamental and structural purposes.
Lead's chemical symbol comes from the Latin word for waterworks, plumbum.
Many magnificent buildings erected in the 15th and 16th centuries still stand under their original lead roofs.
Grey colour
Very soft
Low melting point
Ductile and malleable
Very toxic
The properties of lead that make it useful in a wide variety of applications are density, malleability, lubricity, flexibility, electrical conductivity, and coefficient of thermal expansion, all of which are quite high; and elastic modulus, elastic limit, strength, hardness, and melting point, all of which are quite low. Lead also has good resistance to corrosion under a wide variety of conditions. Lead is easily alloyed with many other metals and casts with little difficulty.
The high density of lead (11.35 g/cm3, at room temperature) makes it very effective in shielding against x-rays and gamma radiation. The combination of high density, high limpness (low stiffness), and high damping capacity makes lead an excellent material for deadening sound and for isolating equipment and structures from mechanical vibrations.