Optimization Of Turning Operations Using High-Speed Steel Cutting Tools

Abstract

Evidence is presented to show the influence of the cutting tool geometry in increasing the turning operation efficiency. Three different high-speed steel cutting tool geometries were introduced. For all the three tools, the angles forming the tools point are the same with exception of the approach angle which is varying. Experiments on the lathe machine were done to test each tool for high efficient cutting operation. The test involved a turning operation on a specified workpieces made of mild steel material. During the test three specified (size, hardness) high-speed steel tools with different approach angles (90o, 60o and 45o) were used to cut the workpieces. The aim of the test is to allow as higher as possible cutting speed to be used by each tool. The operations were dry rough cutting performed at constant depth of cut and feed rate. At varying spindle speeds of lathe machine used to test the operation, cutting speeds were calculated for each tool and recorded in tables of chapter six. Then from cutting speeds of failure of tools, values of Taylor's exponent (n) was found, so that it is possible to calculate tool life for the tools at any cutting speeds. A comparison between the tools based on the tool life was made. As a result, high-speed steel cutting tool with 45o approach angle is able to perform adequately at higher cutting speed and longer tool life than the 60 degree and 90 degree approach angles tools investigated in this work. Therefore, investigation of efficient operation was carried when high-speed steel tool with 45o approach angle is used. As final stage of this research work, calculations were made to find the optimum parameters. These calculations were done using equations illustrated in chapter four. They mainly based on the results obtained from the tests and the information provided in chapter six. The most important parameters calculated were the optimum cutting speeds and tool life for minimum cost and high production rate. For providing economical information about the process, production time and production costs were also calculated.