Tool wear in Ti-6Al-4V alloy turning under oils on water cooling comparing with cryogenic air mixed with minimal quantity lubrication

• Published in: International journal of advanced manufacturing technology 2015-10, Vol.81 (1-4), p.87-101
• Main Authors: Lin, Haisheng, Wang, Chengyong, Yuan, Yaohui, Chen, Zhihua, Wang, Qimin, Xiong, Weiqiang
• Format: Article
• Language: English
• Subjects: Air temperature; CAE) and Design; Computer-Aided Engineering (CAD; Cryogenic cooling; Cutting force; Cutting tools; Cutting wear; Engineering; Equipment costs; Hazards; Heat transfer; Industrial and Production Engineering; Industrial applications; Liquid cooling; Lubricants; Lubricants & lubrication; Lubrication; Mechanical Engineering; Media Management; Moisture content; Morphology; Noise pollution; Original Article; Spirals; Spraying; Substrates; Surface roughness; Titanium alloys; Titanium base alloys; Tool wear; Turning (machining); Water pollution; Wear rate
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-015-7062-x

Wet cutting is the most common cooling method used during the cutting of titanium alloys. However, this method is associated with high costs, pollution, and hazards to operators. Minimal quantity lubrication (MQL) is an effective environmentally friendly cooling method, but is not suitable for difficult-to-machine materials because of its low heat transfer capacity. Using cryogenic air mixed with MQL (CAMQL) for cooling has better heat transfer, but high equipment costs and noise pollution limit its industrial application. This paper proposes the use of oils on water (OoW) as a cooling method for the turning of Ti-6Al-4V alloy and aims at exploring the effect of OoW cooling. Both external oils on water (EOoW) and internal oils on water (IOoW) methods are considered. The effects of EOoW spraying location and the amount of water required for IOoW are compared with respect to chip morphology, cutting temperatures, cutting forces, surface roughness, and tool wear. The use of CAMQL at different air temperatures is compared with wet and dry cutting. The results show that the chips created by OoW and CAMQL are continuous spirals. Compared with CAMQL, use of IOoW cooling with an appropriate amount of water or EOoW cooling from a proper location yields lower surface roughness and slower flank wear rate, and bare areas on the cutting tool substrate were absent because of better lubrication. The properties of the lubricants have an influence on IOoW and CAMQL, but not on EOoW. A suitable cutting tool coating should be selected to ensure the best cutting performance under these cooling methods.