Britannia metal

Britannia metal, also called " Britannium " is a group of pewter alloys with the bluish -prone, silver-white color. Tin alloyed with antimony, usually together with copper, in addition, nickel, lead and bismuth.

Britannia metal is differentiated by definition part of pewter ( pewter ), partly Britannia metal is considered as a special case of Pewter ( with Britannia metal than the harder alloy with more antimony, little or no lead). In the German-speaking world (after Richter) Pewter assigned to the Britannia metal ( pewter than from the UK ) do.

Definition

Britannia as metal alloys in the broadest sense can be referred to, which contain 65 to 97 % tin, 1 to 24 % antimony and 1 to 5 % of copper and bismuth. Is described as Britannia metal or Vickers White Metal is an alloy of 93 % tin, 5% antimony and 2% copper (Encyclopedia Britannica ). Often proved suitable for the casting has an alloy of 90 % tin and 10% antimony as it fills well the molds during cooling. This is also referred to in sources as Britannia metal.

There are different alloys, which are attributed to the Britannia metal ( by judges) include:

  • Metal spoon, English: 82% tin, antimony 16 %, 2% copper.
  • Metal spoon, German: 72% tin, 24% antimony, copper 4%.
  • Pewter for pitchers: 81% tin, 6% antimony, copper, 6%, Lead 7% ( ).
  • Queens - metal cans: 89% tin, 7% antimony, 2% copper, bismuth 2%.
  • Tutaniametall: 86% tin, 10% antimony, copper, 3%, 1% lead.

Properties and Uses

Britannia metal is due to the alloy with antimony significantly more brittle and harder than tin, which allows machining and polishing. However, it is not substantially fixed. The break is fine.

The alloy is mainly used for castings, including but not limited Pewter, ornaments, buttons, bearing metal, printing plates. It is, for example, used to make the famous statuette, the Oscar or Academy Award of Merit.

Because of the brittleness only the alloys with higher tin concentration suitable for rolling. The addition of lead increases the strength without reducing the same extent as antimony ductility. The casting properties are better. However, losing items with lead in the alloy rapidly gloss, gray and can not be used because of the toxicity of lead for food.

Preparation of the melt

Only melting of the copper ( as provided ), then the addition of tin, antimony, and reducing the heat, since the alloy has a much lower melting point because of the high melting point.

Utilizes brass preferably forms, they were previously gerußt or elutriated with bloodstone and preheated for camber cast up to the melting temperature.

Slow cooling is useful if, for example, bells for a good sound is desired. For cooling, it should stay an hour in paraffin at the beginning about 230.degree.

After casting, the surface is grayish white and shiny only by polishing. Another finishing option is to silver castings (electrically ).

Britannia metal is soldered.

Similar alloys

  • Ashberrium (like Engl. Excl metal spoon. 1% zinc, 1% nickel, 1% aluminum).
  • Argentine metal ( 94-97 % tin, 5-2 % copper, 0.5% antimony, or 2/ 3% bismuth )
  • Minofor - metal ( ≈ 66 % tin, 17-20% antimony, 3-4 % copper, ≈ 9% zinc, and 1% iron)

For tin figures and ornaments will also solder alloy ( 4 parts tin, 3 parts of lead ) is used (often with about 3 % antimony for more hardness).

Babbitt (metal) Hematite
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