Shuuichi Shutou

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil Comparison of Cutting Performance with Dry Cutting

Abstract-This paper compares the cutting performance of minimal quantity lubrication (MQL) system with dry cutting in terms of flank wear, crater wear and finished surface roughness when using various kinds of cutting tools. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When using an uncoated tool, TiNand (Al, Ti) N-coated tools without coating on the rake face, and fully TiNand (Al, Ti) N-coated tools, MQL decreases the flank wear, crater wear and finished surface roughness compared with the wear and the roughness by dry cutting, particularly at the high cutting speed of 159 m/min. The reason suggested is the lubricating properties improved even with an extremely small quantity of cutting oil, which reduces the occurrence of deposited metal on the cutting edge. (2) With both the fully TiNand (Al, Ti) N-coated tools, the MQL system showed better cutting performance in terms of reduced tool wear and reduced finished surface roughness compared with that by dry cutting; in particular, the fully (Al, Ti) N-coated tool is suitable for an MQL system in hobbing.

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil Influence of Hardness of Work Materials Under Several Cutting Conditions

This paper deals with the influence of hardness of work materials on flank wear, crater wear and finished surface roughness when using two types of high-speed steel (HSS) hob tool materials coated with (Al,Ti)N film. Specifically, hobbing with a minimal quantity lubrication (MQL) system is compared with dry hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results are summarized as follows. (1) With SCM415 work material changed to hardness HB131, HB144 and HB161 by heat treatment, flank wear and crater wear of the tool are small when cutting comparatively hard HB161 work material, irrespective of the change in hob materials and cutting speeds. (2) With SCM435 work material changed to hardness HB172, HB195 and HB214, flank wear and crater wear tend to be small when cutting annealed HB172 work material. (3) When cutting SCM415 of hardness HB161 and SCM435 of hardness HB172, the finished surface roughness is small and the surface roughness of SCM415 is smaller than that of SCM435. (4) SCM415 of hardness HB161 is suitable for an MQL system in hobbing in terms of flank wear, crater wear and finished surface roughness.

Effect of Cutting Oil Viscosity on Tool Wear Reduction in Turning Using an MQL System

The present paper describes the influence of the viscosity of cutting oil on tool wear and the roughness of the finished surface when using a cemented carbide tool in dry and minimal quantity lubrication (MQL) systems for turning. The following results were obtained. (1) At a feed rate of 0.2 mm/rev, the side flank boundary wear reduction effect was obtained with cutting oil having a low viscosity of 4.9 mm 2 /s in the MQL system, irrespective of cutting speed. The front flank boundary wear increased in MQL compared to dry cutting, and double boundary wear was observed. (2) At a feed rate of 0.4 mm/rev, cutting oil having a moderate viscosity of 9.3 mm 2 /s provided suitable side flank boundary wear, irrespective of cutting speed. (3) The front flank boundary wear obtained using the MQL system was greater than that for dry cutting. The transcription of the groove of this front flank boundary wear formed the finished surface roughness. KeywordsCutting; Turning; Dry; MQL; Viscosity Grade; Tool Wear; Finished Surface Roughness