Experimental investigation of tool wear and chip formation in cryogenic machining of titanium alloys
Experimental investigation of tool wear and chip formation in cryogenic machining of titanium alloys作者机构:Institute of Machining Technology TU Dortmund University Baroper StraBe 303 44227 Dortmund Germany
出 版 物:《Advances in Manufacturing》 (先进制造进展(英文版))
年 卷 期:2015年第3卷第4期
页 面:292-299页
核心收录:
学科分类:08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程(可授工学、理学学位)] 0802[工学-机械工程] 080201[工学-机械制造及其自动化]
主 题:Titanium alloys . Cryogenic cooling Machining . Tool wear Chip formation
摘 要:Titanium alloys are one of the most important design materials for the aircraft industry. The high strength-to-density-ratio and the compatibility with carbon fibre reinforced plastic are the reasons for a raising application in this field. The outstanding properties lead to challenging machining processes. High strength and low heat conductivity affect high mechanical and thermal loads for the cutting edge. Thus, the machining process is characterized by a rapid development of tool wear even at low cutting parameter. To reach a sufficient productivity it is necessary to dissipate the resulting heat from the cutting edge by a coolant. Therefore the cryogenic machining of two different titanium alloys is investigated in this work. The results point out the different behavior of the machining processes under cryogenic conditions because of the reduced thermal load for the cutting tool. According to this investigation, the cryogenic cooling with COa enables an increase of the tool life in comparison to emulsion based cooling principles when machining the α+β-titanium alloy Ti-6Al-4V. The machining process of the high strength titanium alloy Ti-6Al-2Sn-4Zr-6Mo requires an additional lubrication realized by a minimum quantity lubrication (MQL) with oil. This combined cool- ing leads to a smoother chip underside and to slender shear bands between the different chip segments.