Evaluatıon Of The Effect Of Deep Cryogenıc Treatment Ramp Functıon On The Performance Of Coated Cuttıng Tools


Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2020

Thesis Language: Turkish

Student: SERVET ŞEHİRLİ

Supervisor: ADNAN AKKURT

Abstract:

In this work, deep cryogenic process (DCP) was applied to the end mill cutting tools coated with Aluminum Chrome Nitride (AlCrN). In order to achieve the goals of the work, a DCP unit was designed and produced. DCPs with 3 different ramping functions were applied to the samples as 0.25 ° C / min, 0,5 ° C / min and 1 ° C / min. The samples were kept at -196 ° C for 3 different periods of 24, 36 and 48 hours for a ramping speed. Micro hardness measurements were made on the experience tests obtained after DCP. Among the tests, the highest hardness value was obtained with the ramping speed of 0.25 ° C / min in the DCP follow-up, while the low hardness value was found in the cutting tool with DCP applied with a ramping speed of 1 ° C / min. Then the end mill cutting tools were used to surface mill on AISI 4140 material. During milling in dry cutting conditions, the connection is air blown to prevent chips from entering between the tool and the workpiece. Tool wear and roughness on cutting surfaces were determined on AISI 4140 material. The most wear was discovered on 0,5 ° C / min 48 hour group, while the lowest wear was seen in the 0.25 ° C / min 24 hour group. The best surface roughness value obtained was determined on the surface machined with the tool with 0.25 ° C / min 48 hour group in face milling and 0.25 ° C / min 24 hour cutting group in peripheral milling. In the evaluations made within the selected ramping speeds and holding times, the best tool life target was reached with the tool that was achieved with 0.25 ° C / min and 24 hours holding time.