The possibility of application of the acoustic emission method for monitoring friction processes

This article presents the methodology and research results of monitoring friction processes between couple of cooperating elements by acoustic emission method. The research was carried out at the lathing machine test stand of the Technische Hochschule Mittelhessen. The test stand included lathing machine Proxon PD 210, shaft, made of austenitic stainless steel X2CrNi18-9 and steel plate, made of S235. The Friction process was monitored by an acoustic emission set made by Physical Acoustics Corporation (PAC). The PAC system includes: preamplifier USB AE Node, type 1283 with bandpass 20 kHz – 1 MHz, AE signal measurement sensor type VS 150M, with a frequency range 100-450 kHz, computer with AE Win for USB Version E5.30 software. During the study, the acoustic emission (AE) generated by friction between shaft and steel plate was recorded. The load of the plate was 0, 1, 2, 3, 4, 5 and 10 N. The following parameters were determined: amplitude, number of events – hits, the effective value of the signal (RMS). The use of grease between the cooperating elements caused a significant reduction in friction and thus the power of the generated signal (10 to 30 times). In the case of dry friction, without grease, the maximum RMS value was recorded at 4 N load and at the lubricant between the pair cooperating at 1 N load. The research has shown that it is possible to monitor the friction process between cooperating elements using the acoustic emission method