Tribological phenomena in steel-composite brake material friction pairs

Friction layers and friction films on PMC brake pads

“…Further experiments corroborated this view [3][4][5][6][7][8][9][10][11]. Species like iron [4], iron oxides [1,3,4,8,11], barium sulphate [3,6], copper oxide [11], copper sulphide [11], carbonaceous products [1,5,6,10,11] and several other phases [3,11] were identified in third bodies after braking.…”

“…The third body approach suggested by Godet [2] implies that wear particle compaction plays a major role during formation of such surface layers, as also stated by Jacko et al [1]. Further experiments corroborated this view [3][4][5][6][7][8][9][10][11]. Species like iron [4], iron oxides [1,3,4,8,11], barium sulphate [3,6], copper oxide [11], copper sulphide [11], carbonaceous products [1,5,6,10,11] and several other phases [3,11] were identified in third bodies after braking.…”

“…Some authors call it friction film [1,3], others friction layer [4,5]. Filip et al [11] used both terms, since they observed a carbonaceous film on top of the friction layer-the latter consisted of compacted wear debris-but also at regions where no friction layer was present.…”

Selection of Best Formulation for Semi-Metallic Brake Friction Materials Development

“…All hot friction coefficients of the prototype samples reduced except sample SM8. This phenomenon may be due to the formation of metallic layer [Talib, 2001;Scieszka, 1980;Lim et al, 1987] and carbon layer [Begelinger et al, 1973;Zhigao & Xiaofie, 1991]. Sample SM1 and SM2 have lower average thickness loss than the commercial sample.…”

“…It can be seen from the fade test, the coefficient of friction decreases with increased in temperature. This is attributed to physical and mechanical, chemical and microstructural changes on the contact surface [Scieszka, 1980;Jacko, 1977;Talib et al, 2003;Ingo et al, 2004].…”