FE > Semester 1 > Applied Chemistry 1

Marks : 04

Years : DEC 2015

Solid lubricants are used for certain system where oil and grease are either undesirable or inadequate.

Solid lubricants are generally used in the following cases-

• When heavy machinery is to be operated at high speed and moderate load or at very high load and low speed.

• When the machine parts are not easily accessible.

• When machines are at high working temperature and pressure.

Graphite as solid lubricant-

Graphite has a layered lattice structure with weak bonding between layers, providing excellent lubricity as long as moisture is available. Graphite solids provide:

• High-temperature stability

• Good lubrication in high humidity

• Low coefficient of friction under high loads

• Protection against fretting corrosion