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1

Estimation tool for optimum cutting condition of difficult to cut materials

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Soe Y. H. , Tanabe I. , Iyama T. , Da Cruz J. R.

Journal of Machine Engineering

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2012

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tom Vol. 12, No. 1

76--88

EN

Titanium alloy and nickel alloy are mainly used for several aeronautical parts due to their high strength and durability at high temperature. However, thermal conductivity of these materials are very low and most of the heat generated during cutting are concentrately conducted into the cutting tool. Therefore, the tool become extremely high temperature resulting shorter tool life. In this paper, a method for calculating the optimum cutting condition for cutting low thermal conductivity materials such as titanium alloy and nickel alloy is developed and evaluated. The temperatures on the cutting tool tip for various combination of tools and work piece materials were calculated by dynamic FEM simulation and the estimation tool for optimum cutting condition is created based on these results. The amount of heat flow and the temperature on the cutting tool were calculated based on cutting theory. Then, optimum cutting conditions for those materials were estimated by newly developed program. The method was finally evaluated by several experiments. It is concluded from the results that (1) The developed program is applicable for estimation of optimum cutting conditions regarding titanium alloy and nickel alloy. (2) Titanium alloy (Ti6Al4V) can be machined with longer tool life using estimated optimum cutting condition.

2

Development on technique regarding change of resonance frequency on machine tool for optimization of cutting condition

100%

Da Cruz J. R. , Tanabe I. , Inoue Y.

Journal of Machine Engineering

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2014

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tom Vol. 14, No. 3

35--47

EN

Establishment and selection of proper cutting condition can improve tool life and final cutting result. Cutting speed, feed speed, depth of cut and selection of tools are conditions of cutting that determined the cutting accuracy. However, when the optimum cutting condition with selected cutting speed coincides with machine resonance frequency, large vibration will occur. Consequently, even small periodic of driving forces can produce large amplitude vibrations. The simple technique to lower resonant frequency of machine tool was developed in previous research by using mixture of water and polymer with 6wt% concentration. As it was difficult to obtain damping ratio when the concentration is larger than 6wt%, therefore, the aim of this paper is to change machine resonant frequency for optimizing cutting condition by improving mixture concentration of water and polymer. It is concluded from the results that (1) By controlling machine tool resonance frequency enable cutting speed to be used for processing at its optimum cutting condition (2) New damping value of polymer mixed with water was presented, (3) Machine vibration reduced as resonance of machine was successfully avoided and surface roughness was also improved.

3

Lapping system for improvement of geometrical accuracy using lathe machine

100%

Soe Y. H. , Tanabe I. , Iyama T. , Da Cruz J. R.

Journal of Machine Engineering

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2012

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tom Vol. 12, No. 1

28--40

EN

The geometrical accuracy of the products are essential for high quality and interchangeability. Lapping processing is mostly using for final improvement of geometrical accuracy. Geometrical accuracy includes cylindricity, circularity and straightness. In this paper, lapping processing using a normal lathe was investigated for improvement of geometrical accuracy. Firstly, normal turning process is taken and then, the lapping process is performed using the same lathe. The lapping tool consists of a lapping head made of polypropylene (PP), a coil spring for supplying lapping pressure and holder for fitting on tool post. Lapping slurry is composed by mixing water, PEO (Polyethylene Oxide) and diamond grain. This lapping slurry is supplied between the work piece and the lapping head during lapping processing. The lapping head is made to contact and leave from work piece in regular intervals for catching new grains and removing chips. The optimum lapping condition was investigated for high productivity and high accuracy by experiments. It is concluded from the results that; (1) The geometrical accuracy were improved by using developed lapping system with ordinary lathe machine. (2) The optimum lapping condition was revealed experimentally. (3) The surface roughness and dimensional accuracy are also improved using this developed lapping system.

4

Development of immersed machine tool and machining in the strong alkaline water for reduction of CO2

100%

Da Cruz J. R. , Tanabe I. , Sakaguchi N.

Journal of Machine Engineering

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2014

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tom Vol. 14, No. 3

71--82

EN

Nowadays, eco-friendly manufacture has become common request in the manufacturing and production. The excessive electric power associated with the usage of large amount of oil for cooling and lubrication during machining can increase the CO2 emission which is considered as large problem for environment. On the other hand, the presence of the unwanted vibration during machine can affect the quality of production. The influence of immersed machine tool in strong alkaline water has been investigated in previous work for normal machine operation when no vibration occurred. In present research, the influence of immersed condition to the vibration of the bench lathe machine was investigated. Thermal deformations of the spindle when operating bench lathe coincide with machine resonances were also measured for evaluation of accuracy. The calculation of CO2 emission using immersed bench lathe machine was done by comparing with the conventional machining. It is concluded from the results that; (1) Excellent cooling efficiency can be achieved by using strong alkaline water added with microbubble, (2) Vibration of machine tool was reduced during immersed condition, (3) Thermal deformation of the bench lathe was very small despite no-forced cooling was used, (4) The large number of CO2 that released annually can be reduced by immersed of machine tool.