Babbitt Metal

Mahatma Gandhi MissionsCollege of engineering and technologyNoida, U.PBabbitt MetalPresented by: Guided by:Prince Raghav Mr. A.K Sinha

INTRODUCTIONBabbitt metal ,also called white metal.It is a white non-ferrous alloy which is used provide a bearing surface.

HISTORY Babbitt was first created by Issac Babbitt.

In 1839 , he received a patent for a white metal alloy that showed excellent bearing properties. HOW BABBIT WORKS.It provides a bearing surface itself ,which relatively has low coefficient of friction .

This means ,even without lubrication ,Babbitt bearings will have much less friction than if a shaft was turning in other metal.

However ,with the addition of simple lubrication ,Babbitt bearing can have amazingly low coefficient of friction even lower than that of ball bearing .Types of Babbitt MetalBabbitt metal can generally be broken into two major families :Tin based alloy Lead based alloy

Difference b/w Lead and Tin based Alloy Lead TinThe composition range from 15 to 10 % Sn ,10% tin and rest lead.The composition range from 80 to 90% tin ,3to 8% Cu,4to 14% Sn .Lead - based materials are less costly.Tin based material are costlier.They are softer than tin based alloy .On the increment of Cu & Sn increases hardness.It will work fine for most light duty &low speed applications .It is the best choice for high speed applications such as planer and jointers. Eco Babbitt Generally , composition Babbitt alloy has found about 90%Sn 7%Zn 3%Cu that is not technically a Babbitt metal.

Selection of Babbitt Metal In selecting the proper type of Babbitt for a particular job , number of factor to take into the consideration ,the most important of which are as follows:Surface speed of the shaft.Load that bearing is required to carry.

Recycling of Babbitt MetalBefore re-melting and re-machining on Babbitt scrap following methods are followed by the industry to remove impurities with Babbitt scrap are as : Magnetic separatorRotary dryerCrucible furnace

Modern Babbitt BearingUntil the mid 1950s poured Babbitt bearing were common in automotive industry.

In more modern practice , Tin based Babbitt bearing were used as they could stand up to impact load found on the connecting rod or crank shaft.

Babbiting The inner surface of the steel shell is plated with the coating of bronze which is in turn coated with thin layer of Babbitt metal as bearing surface .

The process of laying down this layer of white metal is known as babbitting .