A study on emission of airborne wear particles from car brake friction pairs
2015 (English)In: SAE International Journal of Materials & Manufacturing, ISSN 1946-3979, E-ISSN 1946-3987, Vol. 9, no 1, 147-157 p., 2015-01-2665Article in journal (Refereed) Published
The emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles were obtained by a fast mobility particle sizer and an optical particle sizer. The temperature was measured by a thermocouple installed in the disc. The experiments show that as the temperature increases from 100 to 300 °C the emission of ultrafine particles intensifies while that of coarse particles decreases. There is a critical temperature at which the ultrafine particle emission rate rises stepwise by 4 to 6 orders of magnitude. For the friction pairs investigated, the critical temperature was found to be between 165 and 190 °C. Below the critical temperature, fine particles outnumber coarse and ultrafine particles, although coarse particles make up the bulk of the particulate matter mass. The friction pairs differ in the ultrafine particle emission rate by 1 to 2 orders of magnitude. Above the critical temperature, ultrafine particles constitute almost 100% of the total particle number and their relative mass contribution can exceed 50%. Analysis of the particle size distributions revealed peaks at 0.19-0.29, 0.9 and 1.7 μm. Above the critical temperature, one more peak appears in the ultrafine particle range at 0.011-0.034 μm.
Place, publisher, year, edition, pages
2015. Vol. 9, no 1, 147-157 p., 2015-01-2665
IdentifiersURN: urn:nbn:se:kth:diva-169695DOI: 10.4271/2015-01-2665ScopusID: 2-s2.0-84975807242OAI: oai:DiVA.org:kth-169695DiVA: diva2:824628
FunderEU, FP7, Seventh Framework Programme, 324385
QC 201602112015-06-222015-06-222016-09-20Bibliographically approved