Friction and wear of friction materials containing two different phenolic resins reinforced with aramid pulp

Friction and wear characteristics of automotive friction materials containi ng two different phenolic resins (a straight novolac resin and a modified n ovolac resin) were investigated using a pad-on-disk type friction tester. S ix different friction materials with different relative amounts of the phen olic resins and aramid pulp were manufactured and tested. Two different tes t modes were employed to examine the friction characteristics concerning ac cumulated thermal history (a constant initial temperature test: test mode I ) and friction heat (a constant interval test: test mode II). Friction char acteristics such as friction stability and wear resistance were changed sig nificantly according to the type of phenolic resins and to the relative amo unt of the resin and aramid pulp. Friction materials with the modified novo lac resin showed better friction stability than those with the unmodified n ovolac resin. In particular, the friction materials that were reinforced wi th 10 vol.% of aramid pulp showed substantial improvement on friction stabi lity regardless of the resin type. However, the friction materials with the modified resin showed significant reduction in wear resistance. (C) 2000 E lsevier Science Ltd. All rights reserved.