Friction and Scuffing Resistance Characteristics of Piston Materials as Investigated by a Reciprocating Test Rig

Friction and scuffing resistance characteristics of two piston alloy materials have been investigated by using a long-stroke reciprocating test rig. Tests were conducted under the same load, speed, and starved changing to dry lubrication conditions until the scuffing failure occurred, as indicated by a sudden change of the frictional force signal which was monitored continuously. Measured friction coefficient and scuffing threshold and life results were obtained, and the piston alloy with the better scuffing resistance capability has been identified. Surface texture of new and scuffed piston and cylinder bore specimen surfaces have been measured and characterized by a combination of amplitude and spacing parameters.