Babbitt metal, also called white metal, is an alloy used to provide the bearing surface in a plain bearing. It was invented in 1839 by Isaac Babbitt in Taunton, Massachusetts, USA. The term is used today to describe a series of alloys used as a bearing metal. Babbit metal is characterized by its resistance to gall.
Common compositions for Babbitt alloys:
90% tin 10% copper
89% tin 7% antimony 4% copper
80% lead 15% antimony 5% tin
Originally used as a cast in place bulk bearing material, it is now more commonly used as a thin surface layer in a complex, multi metal structure.
Babbitt metal is soft and easily damaged, and seems at first sight an unlikely candidate for a bearing surface, but this appearance is deceptive. The structure of the alloy is made up of small hard crystals dispersed in a matrix of softer alloy. As the bearing wears the harder crystal is exposed, with the matrix eroding somewhat to provide a path for the lubricant between the high spots that provide the actual bearing surface.
Showing posts with label Babbitt metal. Show all posts
Showing posts with label Babbitt metal. Show all posts
Friday, October 23, 2009
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