Iridium Alloy for Spark Plug Electrodes

  1. Dr. P. J. Winkler
  1. Muriel Graff1,
  2. Bernd Kempf2 and
  3. Jürgen Breme3

Published Online: 23 DEC 2005

DOI: 10.1002/3527606025.ch1

Materials for Transportation Technology, Volume 1

Materials for Transportation Technology, Volume 1

How to Cite

Graff, M., Kempf, B. and Breme, J. (2000) Iridium Alloy for Spark Plug Electrodes, in Materials for Transportation Technology, Volume 1 (ed P. J. Winkler), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527606025.ch1

Editor Information

  1. DaimlerChrysler AG, Forschung und Technologie, Postfach 800 465, 81663 München, Germany; Tel.: 089–607 22393; Fax: 089–607 28627

Author Information

  1. 1

    Technische Universität Darmstadt, Fachbereich Materialwissenschaft, Physikalische Metallkunde, Darmstadt, Germany

  2. 2

    Degussa-Hüls AG, Hanau-Wolfgang, Germany

  3. 3

    Universität des Saarlandes, Lehrstuhl für Metallische Werkstoffe, Germany

Publication History

  1. Published Online: 23 DEC 2005
  2. Published Print: 20 APR 2000

Book Series:

  1. EUROMAT 99

ISBN Information

Print ISBN: 9783527301249

Online ISBN: 9783527606023



  • transportation technology;
  • materials;
  • automotive;
  • iridium alloy;
  • spark plug electrodes


In order to achieve longer service times and reduce fuel consumption in the automotive industry, spark erosion resistant but expensive platinum alloys are used for spark plug electrodes. The necessity of reducing costs and maintaining high quality materials leads us to the investigation of cheaper iridium alloys for this application. Iridium has a high melting temperature but the volatile oxide IrO3 is stable above 1000°C, which accelerates electrode erosion. Therefore iridium can replace platinum only when it is protected against oxidation, for example through alloying, so that the alloying element oxidizes and forms a protective oxide layer at the electrode surface. The aim of this work is to find alloying elements which enhance oxidation resistance and minimize spark erosion of the electrodes.