Effect of dipped cryogenic approach on thrust force, temperature, tool wear and chip formation in drilling of AZ31 magnesium alloy
Uğur Köklü, Himmet Coban
Abstract
Magnesium alloys tend to have inflammable nature and chip self-ignition at high cutting speeds under dry machining condition, although they can be easily machined with good surface quality. In the drilling process, cooling and lubrication have a critical impact as it controls heat generation, tool wear, surface quality, and cutting force. In the present study, drilling tests on AZ31 magnesium alloy were performed with dry and cryogenic conditions at various feed rates and cutting speeds. The effect of dipped cryogenic application during drilling on thrust force, temperature, tool wear, and chip formation were investigated. The results showed that the applied cryogenic drilling method provided less tool wear, smaller chips and reduced amount of adhesions. Drilling tests performed in the cryogenic environment increase the thrust forces by 32 %–39 % compared to dry cutting. Spark and chip ignition were not observed even at high cutting speeds during dry cutting.