EFFECT OF FRICTION LINING ADDITIVES ON INTERFACES OF FRICTION COMPONENTS

Since many decades additives have been added to friction lining composites in order to improve braking performance and prolong life of friction components. Various metal sulfides are still used in large quantities as friction lining additives. It was found that lead sulfide and molybdenum disulfide support the formation of a transfer layer on the metal counter part, which reduces wear and stabilizes friction. At higher temperatures these metal sulfides oxidize by tribooxidation. Surface analysis by SEM and ESCA revealed that antimony sulfide does not contribute significantly to a formation of a transfer layer. At rotor temperatures higher than 500 degrees C, no transfer of composite material was detected any more on rotor surfaces, rather a chemical reaction took place. Detected was antimony pentasulfide, which contributes excellently to wear protection at high temperatures. A new additive called "polarized graphite" was found to contribute to a formation of a thin homogeneous transfer layer on the rotor surfaces. These transfer layers reduce brake noise and wear of both friction components and stabilize friction. At rotor temperatures higher than 500 degrees C, no transfer of material takes place any more, rather a chemical reaction of the additive. Metallisation of brake pads - transfer of metal flakes from rotors to brake pad surfaces - is initiated by hydrogen diffusion into the rotor surface. It was found that additives containing zinc- and tin compounds form a metal layer on rotor surfaces, which act as a barrier layer for hydrogen, thus preventing hydrogen diffusion into the rotor surface and thereby eliminating metal pick-up. For the covering abstract see ITRD E119187.

• Availability:
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• Corporate Authors:

  PROFESSIONAL ENGINEERING PUBLICATIONS LTD

  NORTHGATE AVENUE
  BURY ST EDMUNDS, SUFFOLK  United Kingdom  IP32 6BW
• Authors:
  • HOLINSKI, R
• Conference:
  • BRAKING 2002. FROM THE DRIVER TO THE ROAD. PAPERS FROM THE INTERNATIONAL CONFERENCE
  • Location: Leeds , United Kingdom
  • Date: 2002-7-0
• Publication Date: 2002

Language

• English

Media Info

• Features: References;
• Pagination: p. 369-77

Subject/Index Terms

• TRT Terms: Admixtures; Brake linings; Conferences; Durability; Friction; Tests; Wear
• ITRD Terms: 4736: Admixture; 1350: Brake lining; 8525: Conference; 5910: Durability; 5452: Friction; 6255: Test; 5293: Wear
• Subject Areas: Data and Information Technology;

Filing Info

• Accession Number: 00966411
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 1-86058-371-7
• Files: ITRD
• Created Date: Dec 4 2003 12:00AM