Rose's metal, Rose metal or Rose's alloy is a

fusible alloy A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys. Sometimes the term "fusible alloy" is used to describe alloys ...

with a low

melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends ...

. Rose's metal consists of 50%

bismuth Bismuth is a chemical element with the Symbol (chemistry), symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental ...

, 25–28%

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

and 22–25%

tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...

. Its melting point is between . The alloy does not appreciably contract or expand on solidification, this characteristic being a function of its bismuth percentage.

Uses

Rose's metal has several common uses: #As a

solder Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...

. It was used to secure cast iron railings and balusters in pockets in stone bases and steps. #As a heat transfer medium in heating baths. #As a malleable filling to prevent tubes and pipes from crimping when bent. Rose's metal is melted and poured into the tube. It then solidifies in place but remains malleable. This allows the tube or pipe to be bent and reworked without crimping. After the desired shape is achieved the Rose's metal is remelted and removed, leaving the pipe or tube in its modified shape.

History

It was discovered by the German chemist

Valentin Rose the Elder Valentin Rose the Elder (16 August 1736 – 28 April 1771) was a German pharmacist and chemist born in Neuruppin. He is remembered for creation of a fusible alloy known as Rose metal, which is composed of lead, bismuth and tin. Beginning in 1761, h ...

, the grandfather of

Heinrich Rose Heinrich Rose (6 August 1795 – 27 January 1864) was a German mineralogist and analytical chemist. He was the brother of the mineralogist Gustav Rose and a son of Valentin Rose. Rose's early works on phosphorescence were noted in the Quarter ...

Similar metals

References

{{mineral-stub Fusible alloys Bismuth compounds Lead alloys Tin alloys