Papers by Keyword: Milling

Abstract: Milling is one of the most common materials removal processes used in the production of dies, moulds and various aeronautic components. The process performances such as dimensional accuracy, chatter propagation and tool wear are the common problems which can lead to useless workpiece. The traditional method to avoid these problems is the so-called trial and error method, which often has the characteristics of time-consuming. With the advancement of recent computing techniques, one efficient method to determine acceptable process parameters is development of a comprehensive simulation environment. In this paper, efforts are focused on the introduction of a milling simulation procedure proposed recently by the research group of the authors. The key issues such as development of cutting force model, prediction of dimensional errors and stability lobes are described. At the same time, the crucial issues such as calibration of model parameters and simulation algorithms are also highlighted.

Abstract: This paper presents an experimental study on precision milling of high volume fraction SiC_P/Al composites with single flute polycrystalline diamond (PCD) end mills. Based on a series of tests, the present study is focused on surface roughness of machined surface and tool wear of single flute PCD end mills. The effect of cutting parameters such as feed per tooth (f_z) and depth of cut (a_p) on the machined surface roughness (Ra) was investigated. Tool wear was also inspected and analyzed by Scanning Electron Microscope (SEM). According to the results of experiment, there is a layer of aluminum covered on the machined surface. This layer of aluminum can improve the machined surface quality. Through the comparsion of surface roughness in different cutting parameters, it can decrease surface roughness (Ra) by means of using very small cutting parameters. Flank wear and chipping are two main kinds of tool wear. The observed wear mechanism of PCD tools is abrasive wear and adhesive wear. The purpose of this study is to provide an experimental result for further investigation on milling of high volume fraction SiC_P/Al composites.

Abstract: The paper presents research of milling tool inclination angle δ influence (in relation to the cutting surface) on the free surface roughness. Rotational tools with curved cutting edges (ball nose cutter) performed translation movements on the spherical surface of hardened steel work piece (hardness of 50, 62 and 65 HRC). Milling tool with diameter d=1 mm was made of CBN. Roughness measurements were performed in different places of the milling surface with the Taylor Hobson profilometer.

Abstract: Increasing urge to raise production rate and production quality in the industry brings new requests and challenges. One of them is demand for accuracy and precision of produced parts. Especially in the CNC machining, where the expectations are high, the companies face new issues. Therefore, it is very important to recognize, understand and cope with the technological factors influencing the production accuracy and surface quality of CNC machined parts.

Abstract: An article deals with a measurement of flatness of thin-walled parts with low rigidity. The flatness is important for quality thin-walled parts made by milling. Measurement of the variation in the flatness of thin-walled components conventional 3-axis, high-speed 3-axis milling was done. In the first part is description of flatness and definition of thin-walled parts. Second part characterizes the measuring system, the principle of measurement and experimental setup. The last part of this work is evaluation of the experiment, which compares different factors to determinate flatness during machining of thin-walled parts.

Abstract: Verification of programming of various control systems and production of mathematically defined shaped surfaces on 3D CNC milling machine is a challenging technological process. Appropriate design and optimization of tool path is essential for the production of high-quality surfaces with the required accuracy and roughness. This paper presents the design of shaped surfaces in various programming means in order to evaluate both the accuracy of the shape manufactured by the production machine and also by program created shapes for control systems of 3D milling machines. Based on the analysis of mathematically defined shaped surfaces to evaluate both accuracy of shape of 3D milling machine and also applied programs for the programming of the selected control system the shaped surface "Interface" was chosen. The advantage of mathematically described surface is a better way to evaluate the accuracy compare to surface modeled e.g. by Bezier ́s curves. Mathematically described surfaces enable us to optimize their shapes by available mathematical functions. Typical example the derivatives are, which make it possible to search extremes. Verification of the shaped surfaces accuracy according to created control programs was solved using the 3D Carl-Zeiss coordinate system and also HOLOS software. Verified programs for the NC machine programming were in CATIA V5, Pro/Engineer and EqCAM. The result is an optimally designed original EqCAM program for 3D CNC milling machine programming, which generates optimal NC codes and bypasses various built-in interpolations, and by precise control at every step it is possible to achieve maximum accuracy and quality of machined surface for each 3D CNC milling machine.

Abstract: This paper deals with coherencies of temperature and surface roughness by milling procedure. It explains the principle of up and down milling and also explains the fundamental differences between them. It also briefly describes the heat generated, too. A main part of this paper is realization of the experiment, description of the experiment and evaluation of results shown as the resulting values of temperature and subsequent surface roughness. The aim is to find coherencies of temperature and surface roughness by milling procedure.

Abstract: This article focuses on the analysis of tool wear mechanisms in milling of Inconel 718. Inconel 718 is tough and highly temperature resistive material, which is used due to its excellent properties especially in aggressive corrosive medium. Machining of this alloy is still complicated. The feasibility of four inserts tested for milling of Inconel 718 has been shown in the work. Different cutting speeds and feeds were used. Experimental tests were performed in order to analyze wear patterns evolution. It was found influence of cutting conditions and type if insert in tool wear mode.

Abstract: The machining methods such as waterjet cutting, milling, grinding, lapping, etc. are usually used to manufacture glass fiber reinforced composites (GFRCs) parts. Damages will be produced unavoidably in the machining process, no matter which machining method is employed. Subsurface damage is one of the important parameters to evaluate the surface layer damages. The detection method for the subsurface damages of glass fiber reinforced glass matrix (glass/glass) composite after machining is researched. The characteristics of subsurface damages of glass/glass composite after waterjet cutting, milling, grinding and lapping are investigated mainly, when the fiber direction is either perpendicular or parallel to the cutting surface.

Abstract: ts difficult to guarantee the surface quality when processing the carbon/silicon carbide (C/SiC) composites, and also easy to produce burr defect. So firstly the law of the burrs generated on different direction of fiber was analyzed theoretically. And then we milled the C/SiC composites by electroplating diamond cutting tool with different cutting parameters and fiber directions. The cutting force and the burr area size of the milling surface were also tested. After analyzing the results, the milling burr evaluation method was proposed. Then the burr area size of different fiber directions was analyzed, and the effect on the surface quality of fiber direction during milling process was studied. The result shows that the angle between surface laid carbon fiber direction and cutting direction has a significant influence on the processing quality. Milling surface quality was declined in order as 0°, 45°, 90° and 135°. So in order to improve the quality of the milling surface, the angle between surface laid fabric fiber direction and cutting direction should be less than 45°.