Additive Solutions for Subtractive Problems in Cutting Tool - Next Generation Machining Processes for Advanced Alloys.

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The manufacturing industry is a fundamental sector of all industrialised countries. However, the traditional techniques utilised are no longer viable in a social, economic or environmental capacity. One of the major branches of this industry is machining and has two of the largest consumables; cutting tools e.g. drill bits and cutting fluids (a mixture of oil, water and chemical additives that are sprayed at the cutting tool). When in use, cutting tools get very hot and are subjected to high pressures. This causes them to wear down very quickly and become unusable. To prolong the life of the tools, cutting fluids are sprayed directly at them during machining, reducing the temperature and lubricating the surface of the cutting tool. However, cutting fluids are not environmentally friendly, not sustainable, have associated health risks, are unusable in certain applications e.g. nuclear or medical and account for 15-20% of the total manufacturing cost of a component/ product. There have been alternative attempts to thermally stabilise cutting tools over the last 20 years. For very small, stationary tools, a radiator in the tool holder has been utilised to indirectly cool the tool and fluid has been passed through a channel that loops inside the tool and back out through the tool holder. These are not feasible methods for larger, rotating tools. In order to reduce the temperature of some rotating tools, cutting fluids have been delivered from the tool holder, to the end of the tool, through a central hole. However, this method still requires the use of harmful cutting fluids. The aim of this project is to reduce the temperature in cutting tools in pursuance of a longer tool life and removal of the cutting fluid requirement. This will subsequently reduce the amount of material waste and detrimental side effects of cutting fluids.In order to achieve this the following objectives will be investigated: 1) additive manufacturing methods. Additive manufacturing builds a three-dimensional object, layer by layer and enables the development of highly complex internal structures that would otherwise be physically impossible. This will allow for the optimum design of internal cooling channels and flow paths. 2) The optimum design will be found through the application of computational fluid dynamics and thermal analysis, 3) the investigation of flow paths in rotating cylinders, 4) application of optimisation algorithms and, 5) experimental testing of the additively manufactured prototype tools on a specially developed rig.