ABSTRACT

In this work, cutting fluid emulsion was developed from soya beans and the performance of the developed cutting fluid was evaluated by comparison with the conventional cutting fluid (control sample), using its ability to effectively perform as coolant during machining operation. The machining operation employed was the turning operation in which chips produced were collected and their surface finishes measured. The chips collected were evaluated for chip thickness ratio. Also, the temperature variations during cutting operation were measured using an infra- red gun thermometer. Temperature, surface finishing as well as chip formation rates using the developed cutting fluid under different cutting speed (rev/min), feed rate (mm/rev) and depth of cut (mm) was compared with that of the conventional cutting fluid. The average temperature of the work piece when developed cutting fluid was used as cutting fluid was 53.13 oC and that of the conventional cutting fluid was 54.7 oC. The result are very close, hence it shows better result in conducting heat away from cutting region. The developed cutting fluid gave an average high chip thickness of 0.446 mm while that of the conventional cutting fluid was found to be 0.316 mm. The high chip thickness of the developed cutting fluid is probably due to its better lubricating ability which allows easier and deep penetration of cutting tools. The average viscosity of the developed cutting fluid was found to be 31.1 poise at 29 oC, while the convectional cutting fluid was 47 poise at 29 oC. Low viscosity means high viscosity index, the developed cutting fluid has tendency to be fluid at higher temperature than the convectional fluid. In corrosion measurement, the developed cutting fluid shows no sign of corrosion; hence, the fluid has good ability to inhibit corrosion than the convectional cutting fluid.

CHAPTER ONE
 
INTRODUCTION
 
1.1              Background of the Study
 
The use of cutting fluids in metal cutting was first reported in 1894 by F. Taylor who noticed that cutting speed could be increased by 33% without reducing tool life by applying large amounts of water in the cutting zone (Ávila and Abrao, 2001). Cutting fluids increase tool life and improve the efficiency of the production systems providing both cooling and lubrication of the work surface.
Cutting fluids are used to reduce the negative effects of heat and friction on both tool and work piece. Cutting fluids produce three positive effects on the process: heat removal, lubrication on the chip–tool interface and chip removal (Lopez de Lacalle et al., 2006). However, the advantages caused by the cutting fluids have been questioned lately, due to the several negative effects they have caused to in the environment and workerâs health.
When inappropriately discharged, cutting fluids may damage soil and water resources, causing serious environmental impact. On the shop floor, machine operators may be affected by negative effects of cutting fluids, such as skin and respiratory problems (Lopez de Lacalle et al., 2006). In order to make the machining process more ecologically friendly, a near-dryapplication of lubricant have been accepted because of its environmentally friendly characteristics (Sokovic et al., 2001, Dhar et al.,2006 and Suda et al.,2004). But, depending on the machining process, to reduce or eliminate cutting fluids use is not possible. For these cases it is necessary to develop an alternative solution in order to avoid environment and heath damage.