Selection of informative parameters of acoustic emission for determining the speed of wear in a tribosystem at transitional modes

Abstract

Areas of application of acoustic emission method are considered (АЕ) for the study of transients in tribosystems during grinding in. Registration of acoustic signals allows to determine with high precision the time of occurring events, which include the elastic interaction of microvision of connected surfaces, the formation and destruction of adhesion bonds, the appearance of microcracks and the separation of particles of wear. Application of this method will allow to receive information on the state of the surfaces of friction during the transients (grinding in) in the online mode. To substantiate the choice of informative parameters АЕ during the control of the processes of wear in the tribosystem, the change in the speed of wear of the tribosystem in the process of grinding in and the view is presented АЕ - frames of the signal, taken during the transition process tribosystems in the characteristic points. After completion of the transition process (stable operating mode), frame of signals АЕ takes a kind that differs significantly from the transition mode. A large number of experiments carried out on the analysis of the process of trimming of trbosystems have shown that in assessing the rate of wear at transitional modes it is best to use the power of acoustic emission radiation. Experimental studies are presented in the form of experimental dependencies, which represent the average signal strength АЕ for three repetitions of the same type and three tribosystems with different combinations of materials, where along the axis Х The experimental values of the power of acoustic emission signals from the friction zone are placed, the unit of measurement – mV2 /s. Along the axis Y Postponed corresponding calculation values of the speed of dissipation in tribosystems, unit of measurement - J./s. Dependence allows the power measured during the experiment АЕ calculate the value of the wear rate in the tribosystem at a real time point. From the analysis of the obtained experimental values it follows that the variance of the amplitudes and the signal strength АЕ adequately reflect the wear process and are in a functional relationship with the wear rate. This allows us to put forward the assumption that the size of the power АЕ one can judge the value of the rate of wear at any time of the work of the tribosystem, namely in transitional modes. The method is used to determine the maximum values of the wear rate during the transition process АЕ and an informative parameter - signal strength АЕ. Experimentally established that power АЕ correlates with the speed of wear, the correlation coefficient R = 0,98 and adequately reflects the process of working. The obtained dependences allow to determine the speed of dissipation in tribosystems during the transient process by the values of the power of the signals of acoustic emission, which made it possible to develop a method for calculating the rate of wear during grinding in at any point in the transition process.