ASSESSMENT OF ABRASIVE WEAR RATE FOR PTFE-BASED COMPOSITES IN COMBINATION WITH STEEL

This paper presents a study of the tribological wear rate for PTFE-based composites in combination with C45 steel. PTFE composites with the addition of glass fibre, bronze, carbon fibre, and graphite were selected for the study. Tribological tests were conducted in a roller-block combination over an expanded contact area with no lubrication, using an SMC-2 machine. The study assessed the mass and volumetric wear for the test materials and the wear rate index. The highest wear values were noted for the PTFE composite with the addition of bronze, while the lowest was for the PTFE composite with the addition of glass fibre. For all the test materials, the formation of a polymer film on the steel counter specimen was noted.

Sliding Wear Characteristics of Carbon Filled Polytetrafluoroethylene (PTFE) Composite against AISI 304 Stainless Steel Counterface

In the present work, dry sliding wear characteristics of polytetrafluoroethylene (PTFE) composite reinforced with 35% by weight carbon fiber against AISI 304 stainless steel counterface is investigated with a view to consider PTFE composite as an alternative material for automotive applications. Dry sliding experiments were performed on pin-on-disk wear testing machine varying the normal load on pin, disk rotation (rpm) and temperature correlating with the range of pressure, sliding velocity and temperature variation at reciprocating conditions of compressor. A mathematical model to predict specific wear rate in terms of pressure and temperature was developed to understand parametric effect on wear rate. Specific wear rate has been observed to decrease with increase in pressure and temperature. Although, pressure (normal load) has been observed as more significant in lowering specific wear rate than temperature, no significant benefit was observed at higher ranges of pressure. Decrease in specific wear rate with increase in normal load (pressure) can be attributed to formation of transfer film at sliding interfaces. However, it is necessary to characterize transition of formation of transfer film varying with normal load and temperature respectively.