07-26-2014, 11:37 AM
Tin & alloys
Tin was one of the first metals known to man. Throughout ancient history, various cultures recognized the virtues of tin in coatings, alloys and compounds, and use of the metal increased with advancing technology. Today, tin is an important metal in industry even though the annual tonnage used is much smaller than those of many other metals. One reason for the small tonnage is that, in most applications, only very small amounts of tin are used at a time.
It is very costly metal and does not occur abundantly in nature
The most important ore is tinstone or cassiterite ( SnO3 )
Used for preparing solder material , because it melts easily and does not corrode
It is used for coating iron and steel sheets
Used in Bronze
Bluish white shiny colour
Soft, ductile and malleable
Corrosion resistant, rustfree
Low melting point. Melts at 232°C
![[Image: tin.jpg]](http://www.frontdesk.co.in/big/cm/tin.jpg)
![[Image: tin2.jpg]](http://www.frontdesk.co.in/big/cm/tin2.jpg)
Pewter - Pewter is a tin-base white metal containing antimony and copper. Originally, pewter was defined as an alloy of tin and lead, but to avoid toxicity and dullness of finish, lead is excluded from modern pewter. These modem compositions contain 1 to 8% antimony and 0.25 to 3.0% copper.
Dental alloys - Dental alloys for making amalgams contain silver, tin, mercury, and some copper and zinc. The copper increases hardness and strength and the zinc acts as a scavenger during alloy manufacture, protecting major constituents from oxidation. Most dental alloys presently available contain 25 to 27% tin and consist mainly of the inter-metallic compound Ag and Sn. When porcelain veneers are added to gold alloys for high-grade dental restoration, 1% tin is added to the gold alloy to ensure bonding with the porcelain.
Tin was one of the first metals known to man. Throughout ancient history, various cultures recognized the virtues of tin in coatings, alloys and compounds, and use of the metal increased with advancing technology. Today, tin is an important metal in industry even though the annual tonnage used is much smaller than those of many other metals. One reason for the small tonnage is that, in most applications, only very small amounts of tin are used at a time.
It is very costly metal and does not occur abundantly in nature
The most important ore is tinstone or cassiterite ( SnO3 )
Used for preparing solder material , because it melts easily and does not corrode
It is used for coating iron and steel sheets
Used in Bronze
Bluish white shiny colour
Soft, ductile and malleable
Corrosion resistant, rustfree
Low melting point. Melts at 232°C
Pewter - Pewter is a tin-base white metal containing antimony and copper. Originally, pewter was defined as an alloy of tin and lead, but to avoid toxicity and dullness of finish, lead is excluded from modern pewter. These modem compositions contain 1 to 8% antimony and 0.25 to 3.0% copper.
Dental alloys - Dental alloys for making amalgams contain silver, tin, mercury, and some copper and zinc. The copper increases hardness and strength and the zinc acts as a scavenger during alloy manufacture, protecting major constituents from oxidation. Most dental alloys presently available contain 25 to 27% tin and consist mainly of the inter-metallic compound Ag and Sn. When porcelain veneers are added to gold alloys for high-grade dental restoration, 1% tin is added to the gold alloy to ensure bonding with the porcelain.