Adhesive wear occurs when small surfaces of the cutting tool due to friction are micro-welded to the chips and removed from the tool surface. A hypothesis as to whywelding occurs is that an electric potential field arises which initiates a chemical reaction and then welding of the work material and the tool takes place in the cuttingzone. The electric potential field results in a fluttering magnetic field, which in turngenerates electromagnetic issues. The waves should be around and above 1 MHz.The aim of this work is thus to investigate the presence of electromagnetic wavesfrom the cutting zone. The purpose is to compare sound and electromagnetic wavesduring the adhesive process. Previous research shows that the adhesive mechanism is a transient vibration thatmanifests itself as a cluster of waves with a stochastic duration, including a feedbacksystem restricted by the plastic deformation within the chip. Furthermore, the cutting speed is the most important cutting parameter in tool wear and the main wearmechanism at cutting speeds around 200 m/min is the adhesive wear. Several studies showed the emission of electromagnetic waves during plastic deformation ofmetals during tensile test. Frequency ranges for radiations are between 1 and 1000MHz. To investigate the hypothesis, axial turning was performed with a cutting speed190–200 (m/min) and one steel grade, SS2541 was used as a work material. Thedepth of cut and feed were set to 1 mm and 0,196 mm/rev. Detection and measurement of electromagnetic waves was performed with a spectrum analyzerMT8221B with four different signal receivers. A reference measurement was madewhen the turning machine was on without the workpiece being machined and then ameasurement was made during the turning process. The results of measurementsshowed a source of electromagnetic radiation within the frequency range 0–5 MHz.This result was achieved with copper plate as an antenna. To find out how signalsfrom acoustic emission and electromagnetic waves develop during the adhesive wearprocess, sound measurements were performed with microphones during the turningprocess. Results of sound measurement showed that the frequency at which adhesivewear occurs decreases and the amplitude increases as the insert wears. To be able toanalyze how electromagnetic radiation develops with the wear process, measurements must be performed in a shielded space from ambient disturbances, as in aworkshop there are many sources of noise that can affect the accuracy of the measurement. An antenna can be designed so that the measurement can take place asclose to the cutting zone as possible.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:hig-36205 |
| Date | January 2021 |
| Creators | Firoz, Safdari, Yonas, Woldegiorgis |
| Publisher | Högskolan i Gävle, Avdelningen för industriell ekonomi, industridesign och maskinteknik, Högskolan i Gävle, Avdelningen för industriell ekonomi, industridesign och maskinteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | Swedish |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0028 seconds