標題: Lubrication mechanisms of LN2 in ecological cryogenic machining
作者: Hong, SY
機械工程學系
Department of Mechanical Engineering
公開日期: 2006
摘要: Cryogenic machining is considered an environmentally safe alternative to conventional machining where cutting fluid is used. In cryogenic machining, liquid nitrogen (LN2) is well recognized as an effective coolant due to its low temperature, however, its lubrication effect is less well known. Our previous studies of the change in cutting forces, tool wear, chip microstructure, and friction coefficient indicate a possible lubrication effect of LN2. This paper proposes two mechanisms on how LN2 can provide lubrication in the cutting process. To verify these proposed LN2 mechanisms and distinguish them, idealized disk-flat contact tests were performed. A low temperature can alter the material properties and change the friction coefficient between the specimens. However, from the test results, this lubrication mechanism was dependent on the material pairs. An uncoated carbide insert with a low carbon steel or titanium alloy disk test showed reduction of friction under LN2 cooling, but a coated insert increased the friction force. LN2 injection to form a physical barrier or hydrodynamic effect between two bodies is always effective in reducing the friction force.
URI: http://hdl.handle.net/11536/12876
http://dx.doi.org/10.1080/10910340500534324
ISSN: 1091-0344
DOI: 10.1080/10910340500534324
期刊: MACHINING SCIENCE AND TECHNOLOGY
Volume: 10
Issue: 1
起始頁: 133
結束頁: 155
顯示於類別:期刊論文


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