Papers by Keyword: Cutting Temperature

Abstract: This paper proposes the prediction of cutting temperature, tool wear and metal removal rate using fuzzy and regression modeling techniques for the hard milling process. The feed per tooth, radial depth of cut, axial depth of cut and cutting speed were used as process state variables.The experiements were conducted using RSM based central composite rotatable design methodology. Regression and fuzzy modeling were used to evaluate the input – output relationship in the process. It is interesting to observe that the R² and average error values for each response are very consistent with small variations were obtained.Also, the confirmation results show that very less relative error varitions. Thus, the developed fuzzy models directly integrated in manufacturing systems to reduce the more computational complexity in the process planning activities.

Abstract: The surface roughness is monitored using the cutting force and the cutting temperature in the ball-end milling process by utilizing the response surface analysis with the Box-Behnken design. The optimum cutting condition is obtained referring to the minimum surface roughness, which is the spindle speed, the feed rate, the depth of cut, and the tool diameter. The models of cutting force ratio and the cutting temperature are proposed and developed based on the experimental results. It is understood that the surface roughness is improved with an increase in spindle speed, feed rate and depth of cut. The cutting temperature decreases with an increase in tool diameter. The model verification has showed that the experimentally obtained surface roughness model is reliable and accurate to estimate the surface roughness.

Abstract: The nickel-based superalloy GH4169 is widely used in the aerospace industry because of its excellent comprehensive mechanical properties under high temperature and corrosion condition. It is one of the most difficult-to-machine materials due to low thermal conductivity and hard particle. One method of solving the problem of maching difficult-to machine materials is using new material cutting tool. PCBN tool has excellent cutting property in maching nickel-based superalloy because of its great hardness, high wear resistance and good chemical stability. The cutting process of in-depth study of PCBN tool cutting nickel-based superalloy, shows the variation rule of cutting force and cutting temperature, can provide a theoretical basis for process specification high temperature alloy and efficient processing, has a very big practical significance. On the basis of reasonable hypothesis, this paper discusses in detail the transformation from actual turning to 2D orthogonal free cutting geometry model. Based on this,through the establishment of simulation model of PCBN turning the nickel-based superalloy GH4169, studying on the tool rake angle γo, back angle α_o, cutting speed v_c and feed f on cutting process of cutting force and cutting temperature effect.

Abstract: The aluminum alloys are widely used to manufacture large mirror of infrared band optical systems because they have many advantages such as low cost, low mass density, well thermal conductivity, well plasticity and easy manufacturing. In order to imporve the machining efficiency and meet the requirements of suface error and suface roughness of large metal mirror, diamond ultra-precision cutting is used as finish machining to manufacture them. But the diamond tool wear is severe which is induce by the cutting heat and the cutting force during the cutting process. In this work, the metal cutting finit element sofeware-AdvantEdge has been used to study the cutting tempreture in diamond ultra-precision cutting of aluminum alloy, the influence rules of cutting parameters and tool geometric parameters are researched. And the diamond ultra-precesion cutting experiments were performed, the cutting temperature were detected by infrared thermal imager. The results show that the cutting speed exerts the most considerable influence on the cutting temperature, and the cutting temperature increases with an increase in the cutting speed. Although the temperature detected by the infrared thermal imager in the diamond ultra-precesion cutting experiments is lower than that obtained from the simulation of finit element method (FEM), the varied trend of the cutting temperature is the same. So the FEM simulation proves to be true.

Abstract: The aim of this research is to investigate the influence of solidification thermal parameters on the macrostructure of an Al-7wt%Si alloy during the horizontal directional solidification under unsteady-state heat flow conditions and its correlation with cutting temperatures. The solidification experiments were instrumented by thermocouples and an experimental approach was developed to quantitatively determine the solidification thermal parameters considered. The observation of the macrostructures has indicated that the columnar-to-equiaxed transition occurred in a sharp plane parallel to the chill wall and a higher average cutting temperature was obtained for the columnar structure.

Abstract: In this study, tool edge temperature was measured by a two-color pyrometer with an optional fiber and the novel method to evaluate the cooling effect of cutting fluid was proposed. After one cut, the tool edge passes over the fine hole at workpiece where inserted into an optical fiber so that the one peak signal can be obtained by each of two detectors with different spectral sensitivities in the pyrometer. The tool edge temperature can be calculated by taking the ratio of outputs from these two detectors. In previous research dealing with the cutting temperature in end milling obtained by a two-color pyrometer with an optional fiber, the average temperature calculated from some large peak values was used for an index as cutting temperature. However, this method was not suitable to estimate the tool edge temperature in wet milling. In the proposed method, the tool edge temperature was calculated only by the peak signals just after full length cut and used for an index as cutting temperature. The frequency distribution of tool edge temperature was made by the obtained temperature data. Comparing dry cutting to wet cutting, there was almost no difference in maximum temperature but obvious difference in the frequency distribution. The temperature range in wet cutting was wider than that in dry cutting.

Abstract: A method for estimating the cutting characteristics of spiral tap by fluctuation of cutting forces is proposed. The behavior of torque and thrust in tapping is influenced by the change of cutting state. Therefore in this method the fluctuation of cutting forces is depicted in the torque-thrust plane in which the horizontal axis and the vertical axis indicate thrust and torque respectively. Tapping of stainless steel AISI 304 was conducted with several coated spiral taps attached to an axial floating tap holder. The tool edge temperature was also measured by a two-color pyrometer with an optical fiber. When the fluctuating of forces in the torque-thrust plane was similar to a theoretical pattern, the surface of thread did not have obvious geometric damage. In this cutting conditions, there is a strong correlation between tool edge temperature and cross-sectional cutting area.

Abstract: In pocketing operation for mold and die, the variation of tool engagement angle causes variation in the cutting force and also cutting temperature. The objective of this study is to investigate the effect of tool engagement on cutting temperature when using the contour in tool path strategy for different cutting speeds. Cutting speeds of 150, 200 and 250m/min, feedrate from 0.05, 0.1, 0.15 mm/tooth and depths of cut of 0.1, 0.15 and 0.2 mm were applied for the cutting process. The result shows that by increasing cutting speed, the cutting temperature would rise. Varying the tool engagement also varied the cutting temperature. This can be seen clearly when the tool makes a 90^o turn and along the corner region. Along the corner, the engagement angle varies accordingly with the radial depth of cut.

Abstract: Cutting temperature generated during high speed machining operations has been recognized as major factors influence tool performance and workpiece geometry. This paper aims to model the cutting temperature and to investigate cutting temperature behaviours when contour-in tool path strategy applied in high speed end milling process. The experiments were carried out on CNC vertical machining center by involving PVD coated carbide inserts. Cutting speed, feed rate and depth of cut were set to vary. Results obtained indicate that cutting temperature is high in the initial stage of milling and at the corners region or turning points region. Portion of radial width of cut with workpiece in combination with the abrupt change of the milling path direction occur particularly in acute internal corners of a pocket leads to rise of cutting temperature.

Abstract: In terms of method for evaluating the quality of composite metal cutting tools, a need to regard reliability as a factor, consisting of several components, is grounded. It is discovered, that thermal compatibility of processed material and material of the tool, has a significant impact on composite cutters’ durability. So does the force of stress, created in the cutting edge. In order to take all these factors into account when evaluating the quality of metal cutting tools, the need to include stress and thermal compatibility coefficients has been proven. Means to determine the attributes needed and formulas for calculation of those coefficients had been developed. The methods we created can be used for the evaluation of both the existing tools and for the perspective tools currently being developed.