A Statistical Approach to Near Dry Machining

Licentiate thesis, 2009

To substantiate the implementation of near dry machining in such a demanding industry as the aerospace industry, it is essential to have a broad understanding about the phenomena behind near dry machining. The conditions for the aerospace industry is stated in such a way, that changes or method development of the process had to be very well founded before it could be executed. To get closer to such circumstances this thesis has been focused on complement traditional experimental work with collaring a statistical approach to a very broad experimental plan. This statistical approach has also incorporated a simplified significant test. The purpose of doing this is to enable a possibility to distinguish natural variations from significant variations within the process. These imply the possibility of getting a higher degree of universal applicability of the phenomena behind near-dry-machining. The scope of the experimental work was turning operations in four different aerospace materials with two type of cutting inserts and two type of near dry machining cutting fluids and two conditions of the carrier air used. This was compared with reference cutting operations with dry conditions and flood cooling conditions. The result demonstrate significant evidence that cooling is the dominate phenomena for some of the above combinations of work material, type of inserts and type of near-dry machining applications. No clear evidence was shown that lubrications is the dominate phenomena for any of the above combinations. Furthermore significant evidence could be established that cooling of the carrier air during near-dry machining is an important condition for establishing a cutting process with low level of load.