Surface Characteristics Modification of Polyoxymethylene and Polyurethane Using Burnishing

Abstract

The surface characteristics of polymers play an important role in unlubricated sliding applications that involve a polymer–metal interface because they are relatively softer than most metals. In this article, roller burnishing is introduced as a technique to improve the friction and wear characteristic of polymers in such applications. The polymers used in this study are polyoxymethylene (POM) as a thermoplastic polymer and polyurethane (PUR) as a thermosetting polymer. The combination of moderate values of burnishing force and speed is recommended during burnishing operations. The lowest surface roughness value, R _a , achieved for POM is 0.53 μm (32% decrease) and for PUR is 0.57 μm (29% decrease). The tribological behavior of the burnished polymers is found to be predominantly related to their surface quality. The lowest coefficient of friction value achieved in this work for POM is 0.24 (26.8% decrease) for POM and for PUR it is 0.27 (17.7% decrease). The lowest specific wear rate achieved in this work for POM is 0.37 × 10⁻⁶ mm³/Nm (27.8% decrease) and for PUR it is 0.47 × 10⁻⁶ mm³/Nm (25.2% decrease). These findings show that the roller burnishing process has the capability to improve the surface quality and tribological characteristics of POM and PUR.

KEY WORDS:

• Roller Burnishing
• Surface Roughness
• Coefficient of Friction
• Specific Wear Rate

ACKNOWLEDGEMENT

The author thanks Dr. Nabil and Dr. Brevern for supervising this work.

Review led by Robert Bruce