Papers by Keyword: Milling Parameters

Abstract: The spindle speed, federate and axial depth of micro-milling are found to have a significant influence on the micro milling forces and surface roughness through experimental analysis of the micro-end milling process. To investigate these issues, an orthogonal test method is developed in this present work. Firstly, experimental analysis for the micro-milling forces and surface roughness was performed based on the micro-end-milling experiments of AL5083-O by using 0.396mm diameter micro-end mills with a miniaturized machine tool. Then, the datum of experiments were classified and analyzed by the orthogonal test method. Finally, the laws of micro-milling forces and surface roughness with changing process parameters were found and summarized. The spindle speed has a significant effect on the micro milling forces and surface roughness. In a word, the results of this work were useful to understand the characteristics of machining process and improve the machining performances.

Abstract: High energy ball milling has been used like alternative route for processing of materials. In the present paper, the reduction of tungsten oxide by aluminum in order to obtain metallic tungsten was studied using a SPEX type high energy mill. A powdered mixture of WO₃ and metallic aluminum, weighed according to the stoichiometric proportion with an excess 10% Al, was processed with hardened steel utensils using a 1:6 powder-to-ball ratio. The processing was carried out with milling jar temperature measurement in order to detect the reaction type. The temperature evaluation indicated the self-propagating reaction occurrence by fast increase of the jar temperature after a short milling time. The tungsten oxide reduction was verified by X-Ray Diffraction (XRD) analysis and the milling products were characterized by Scanning Electron Microscopy (SEM). The results were slightly different from the literature due to the mill type and milling parameters used in the work.

Abstract: In this paper, effects of milling parameters on cutting force and surface roughness during symmetrical face dry milling process of super high strength steel 30CrMnSiNi2A were presented. Multiple linear regression model and orthogonal rotary quadratic regression model were established to analyze cutting force and surface roughness, respectively. Their adequacy was estimated by variance analysis and experimental data comparison. Parameters optimization for maximum metal removal rate and minimum surface roughness were also discussed.

Abstract: The profile of a single-pass milling can be assumed as a cosine curve. Therefore, the maximal depth model for single-pass milling is established which indicates the quantitative relationship between the AWJ single-pass milling depth and the milling parameters. The depth model of milled surface, which shows the effect of water pressure, standoff distance, lateral spacing, abrasive flow rate and the properties of the material on the AWJ milling depth, is established based on the maximal depth model for single-pass milling. The derived model is assessed by AWJ milling experiments. The results show that the milling depth increases with an increase in water pressure and standoff distance, and decreases with an increase in lateral spacing and traverse speed. The theoretical milling depth predicted by the mathematical model is good agreement with the experimental result.

Abstract: In order to provide experimental evidence for optimizing high-speed milling parameters and controlling surface integrity, the effects of cooling conditions, tool rake angle and milling parameters on machined surface residual stresses were investigated in high-speed milling titanium alloy TC11. The residual stresses were measured by XStress3000 X-ray stress analyzer, and three points were tested on each workpiece surface, then take average. The milling parameters were optimized based on fatigue performance. The results show that the emulsion cooling get the highest surface residual compressive stress and the dry cutting get the lowest residual compressive stress. With the increasing of cutting tool rake angle, surface residual compressive stresses increase. The most effect on the residual stresses of surface is milling width, next are feed per tooth and milling depth, and the last is milling speed. In the experimental range, the optimized high-speed milling parameters are: vc=377m/min, fz=0.03mm/z, ap=0.2mm, ae=7.5mm.

Abstract: Because of the variety of processing methods, broad range and uncertainty of processing parameters when machining aeroengine structure parts, the method of fuzzy orthogonal optimization was used to optimize milling parameters in the light of machining efficiency in machining plane characteristics of aeroengine structure parts. According to analyzing the effects of milling parameters on processing efficiency, the optimized parameters were obtained. The results showed that the established fuzzy orthogonal optimization model can take full account of the uncertainty in the process of cutting parameters optimization. Excellent experimental agreement was achieved in cutting parameters calculated by the established model. The established model has good practicality and high precision. It is easy to understand and can be used to guide the actual production.

Abstract: The surface roughness is difficult to estimate in machining, especially for weak stiffness workpiece. So, prediction model of surface roughness using artificial neural network (ANN) is developed. This model investigates the effects of cutting parameters during milling Aluminum alloy 6061. The experiments are planned with four factors and four levels for developing the knowledge base for ANN training. Three-dimensional surface plots are generated using ANN model to study the effects of cutting parameters on surface roughness. The analysis reveals that cutting speed and feed rate have significant effects in reducing the surface roughness, while the axial and radial depth of cut has less effect. And the variations of surface roughness are highly non-linear with the cutting parameters.

Abstract: Influencing rules of surface roughness for the work-piece by changing major milling parameters are studied when 2A70 alloy are cut by cemented carbide ball-end milling cutter cuts in high-speed. Primary and secondary influence order of test factors are found out through range analysis and variance analysis of test data according to the orthogonal test designed by the manufacture experience. Influencing tendency between milling parameters such as feed per tooth, back cutting depth, milling speed and line width and the roughness are obtained, a prediction model of aluminum alloy surface roughness is built up, surface quality of the product can be predicted and productivity can be analyzed.

Abstract: The mathematic model was established between finished surface residual stress and milling parameters by orthogonal regression testing. The rationality of the model was certified by FEM and test. The simulation hypothesis and process were verified by the model. The test showed that the model and FEM were feasible.

Abstract: Machining parameters such as speed (v), feed (f) and depth of cut (d) play an important role in determining the residual stress as well as the surface roughness of a material. The material used for the present study is a nickel based super alloy Udiment 720 which finds applications in the manufacture of gas turbine engine components. Residual stress and surface roughness measured on this material showed different magnitudes for different combinations of milling parameters but did not reveal any definite trend. Analytical relationships developed between the magnitudes of residual stress, surface roughness and milling parameters indicated that combined effects of the milling parameters influence both residual stress and surface roughness.