Development of Friction Pad and Study for its Wear Characteristics

Abstract

Friction Pads are commonly used in clutches and brakes of the vehicles as a friction material. Powder metallurgy processes are found to be economical to produce friction pads. The process parameters and metal powder characteristics have profound effect on wear characteristics of the friction pad. In the present study an attempt has been made to manufacture friction pad using powder metallurgy process. Copper Powder, Zinc Powder, and Lead Powder of 325 mesh sizes, 300 mesh sizes, and 200 mesh sizes respectively were used to prepare the pads.

In this study optimization of process parameter (sintering temperature, sintering pressure and sintering time) for friction pads using Taguchi Method. Physical Properties (Hardness) and Tribological Properties (Wear) were selected as responses. Analysis of varience (ANOVA) is performed on experimental data. The signal to noice (S/N) ratio analysis is employed to find optimum condition for hardness and wear rate.

Friction pads of 25 mm in Diameter and 12 mm in height were produced. Density (mass/volume) was determined by weighing the specimen and measuring their height and diameter. The pressure was applied in the range of 0 to 4000 kg/cm sq.

The friction pad was manufactured at a 700 degree C, 800 degree C, and 900 degree C with application of hydraulic pressure 300 kg/cm sq., 330 kg/cm sq., and 355 kg/cm sq. respectively and time for sintering were 30 minutes, 45 minutes and 60 minutes respectively. It was determine that sintering pressure has the strongest effect on hardness and wear properties. It was observed that friction materials with the optimal level of parameters proved to be best performer wear characteristics view point. Density of friction pad increases with increasing load, increasing temperature and increasing sintering time. A laboratory-scale pad-on-disc wear characterization system was developed for measurement of the wear rate of the friction pad material. 200 N force was applied on friction pad during wear characterization. Wear of friction pads were decreased with increasing the sintering temperature and pressure.