Interfacial Stress and Failure Analysis for Piston Ring Coatings under Dry Running Condition

Abstract

A two-dimensional thermomechanical finite element model was developed to analyze the sliding process of a piston ring with coating sliding on cylinder liner under dry running condition. Thermal and mechanical effects were considered simultaneously in the model. The aim of the current work is to study the mechanisms of scuffing, failure, and seizure occurrence in a piston ring-liner system. It is shown that coating thickness plays an important role in the thermal and mechanical stress status at the contact area, coating bulk body, and interface of the coating and piston ring substrate. The coating thickness also exhibits a significant influence on the temperature rising at the contact area and interface of the ring coating and substrate, which could cause failure at the interface of the coating and substrate before it happens at the contact surface under some specific conditions. The results also show that thinner coating thickness in some specific range could have a higher possibility of cracking or failure. Furthermore, it is found that the thermal loading is the key cause of scuffing or failure of the piston ring coating.

KEY WORDS:

• Piston Ring Coating
• Interfacial Stress
• Failure Analysis
• Finite Element Method

ACKNOWLEDGEMENT

This work was partially supported by the Fundamental Research Funds for the Central Universities (Code HEUCFZ1117) and Provincial Science & Technology Research Program of Heilongjiang (Code GC08A105). The authors sincerely express their appreciation.