This article discusses observations on thermal stability, decomposition properties and degradation of organic components of friction composite materials fabricated by powder metallurgy techniques. N-Methylaniline modified phenolic resin used as a binder material in the preparation of composite materials. Thermogravimetry method was used to study the thermal properties of the samples. The experiments were performed on a TGA Q50 (TA Instrument) in an oxygen atmosphere. In order to better assess the thermal characteristics of the composites, the analyses were carried out by separating thermographs into three parts according to the degradation mechanism. The obtained results helped to assess the thermal stability of the friction materials. The degradation of phenolic resin was observed in the temperature range of 312–362°C. It was found that barite and copper-graphite particles improve the thermal characteristics of the samples.

No abstract

This paper presents the comparative investigation of temperature distributions in the pin-on-disc tribo-contact with dry friction conditions. Heat generation and distribution mechanism in contact of a pin made by phenolic resin–based brake friction composite and 35HNL steel disc counter-face material were studied. Both experimental and simulation methods were used to study the temperature changes. In order to analyse the thermal effects, the change in the coefficient of friction with time were also characterized. Experimental friction tests performed on universal “pin-on-disc"-type friction and wear test machine model MMW-1. Interface temperature measurements of the disc was conducted non-contact type infra-red laser thermometer. Heat simulations were modelled via finite element method using COMSOL Multiphysics 5.5, Heat Transfer in Solid Module. The simulations helped to determine in the increase of temperature over selected time period. Obtained experimental results compared with results of numerical analysis.

No abstract

The present work considers wear performance of non-asbestos organic (NOA) brake-pad composite materials. The specimens were manufactured by conventional Powder Metallurgy Methods. The experiments was carried out in dry condition on universal MMW-1 tribometer by pin-on-disc configuration. Tests were conducted based on plan L27 orthogonal array generated through Taguchi technique and mathematical model were developed. The criteria "smaller-is-better" selected to examine the dry sliding behavior of developed composite materials. The wear rate and process variables (contact pressure, sliding velocity and cycles) were examined by analysis of variance (ANOVA) method using Minitab 19.1.1 software. Worn surface examination of the brake-pad materials was done using scanning electron microscope (SEM). The strongest influence on the wear rate was exhibited by the sliding velocity (52.61%), then follow contact pressure (30.47%) and the cycles (16.01%). The studies based on prediction and optimization concluded with confirmation tests.