Frequency analysis and modeling of charged-particle triboemission from ceramics

• Published in: Wear 2003-08, Vol.255 (1), p.686-694
• Main Authors: Molina, Gustavo J., Furey, Michael J., Ritter, A.L., Kajdas, Czeslaw
• Format: Article
• Language: English
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Ceramic wear; Chemical industry and chemicals; Exact sciences and technology; Exoemission; Friction, wear, lubrication; General studies; Generalized Poisson distribution; Machine components; Mechanical engineering. Machine design; Technical ceramics; Triboemission
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/S0043-1648(03)00097-8

The triboemission of charged particles during sliding contact is one measurable but often neglected output during wear of ceramics. Previous research work by the authors suggested that some boundary-lubricant reactions may be initiated and controlled by triboemitted electrons, but the origin and mechanisms of the triboemission phenomena remain largely unknown. The authors used a new tribometer, whose features and capabilities were previously reported, to measure electron triboemission outputs from the sliding contacts of diamond-on-ceramics and other material systems under vacuum. Characterizations were previously presented in the time-domain for those outputs. This paper introduces a new characterization of electron triboemission from ceramics by considering the frequency of occurrence of the emission events. A literature review is included on statistical models for the triboemission phenomena. A transformation to frequency-domain reveals patterns of decaying frequencies of occurrence for increasing number of events in the triboemission outputs from diamond-on-alumina and diamond-on-sapphire contacts. The patterns are complex and several classic frequency distributions are tested for describing it. A new distribution, which was developed by the authors as a “truncated compound Poisson”, shows the best fit to the triboemission data. Finally, the possibility is discussed of using frequency-domain analysis to obtain new understanding of possible mechanisms for charged-particle triboemission.