Failure Mechanisms of an Automobile Clutch Assembly Cast Iron Pressure Plate

Abstract

The present study is focused on the failure mechanisms of an automobile clutch disc/pressure plate assembly due to abnormal operation of a passenger vehicle. Terminal malfunction of the part took place about one year after an accidental overloading incident. This component operates under sliding friction conditions, during which the pressure plate is pressed against the clutch disc with normal load that varies in a non-predictable manner, depending on the driving conditions. Commonly, the clutch disc is considered as ''consumable'' part that can be replaced when malfunction occurs, whilst the metallic pressure plate is considered to remain intact. However, in this particular case, visual inspection, macro-examination and microscopic observation using principally light and scanning electron microscopy of such a cast iron pressure plate revealed its severe long-term progressive failure, through extensive deep grooving and oxidation of the surface and the development of subsurface shear cracks.

Prediction of Surface Treatment Effects on the Tribological Performance of Tool Steels Using Artificial Neural Networks

“…1 Heat treatment aiming to bulk hardening. 2 Surface treatment (nitrocarburizing) after heat treatment.…”

“…The clutch assembly, where the clutch disk slides against the pressure plate to disengage power to the drive train, enabling the vehicle to stop, start, or shift gears [2].…”