Papers by Keyword: Burr

Abstract: A three-dimensional model of micro-turning using the finite element method (FEM) is created in this paper to analyzed the formation mechanism and influencing factors of feed-direction burr in micro-turning. According to the simulation and analysis result, in micro-turning,the deformation of the workpiece feed direction end is the combined action of the plastic bending deformation and shear slip deformation, and plastic bending deformation influences burr height and shear slip deformation affects the burr root thickness. Meanwhile, due to the amount of material involved in different deformation actions is changed, compared with conventional scale cutting, the various influencing factors have significant differences effect on the size of burr.

Abstract: With the development of the times, micro and small products are needed increasingly. The machining accuracy and surface quality are especially important to micro machining. However, in the micro milling, the size of the burr compared with that of the part is much greater than that of conventional milling. Moreover, it is difficult to remove micro milling burr by conventional deburring methods due to the small part size. The existence of burr will not only affect the match of parts, but also reduce the dimensional accuracy and surface quality of the work piece. Therefore, it is important to control and reduce micro-milling burr. Micro-milling experiments are carried out on the material of copper with micro-milling cutter diameter 0.5 mm. Micro grooves are milled with different cutting process parameters. The burrs generated under different conditions are analyzed using orthogonal test method. When the spindle speed and feed rate are constant, burrs increase with the increasing of cutting depth. Keeping the spindle speed and the depth of cut constant, burrs are generated increasingly with the increase of feed rate. And the decreasing of the spindle speed leads to the increase of burrs if the other parameters are constant. The experimental research provides reference for the burr control of micro-milling based on the optimization cutting process parameters.

Abstract: The burr formation and control is one key technology of achieving precision and ultra-precision machining and automatic machining. Based on the theory of system engineering, the metal cutting burr formation, control and removal technology system are constructed in the paper. Then, the basic principles of burr control are presented. Combined with precision and ultra-precision machining and automatic machining, the active control methods and technologies of burr are presented. They are the modified design of parts structure, the option of tool geometry parameters, the adjustment of cutting data and processing technologies optimization etc. So, these methods lay a solid foundation on achieving minimum burrs.

Abstract: Based on analyzing the mechanism of forming exit burr in drilling, the paper researches the process of forming exit burr in low frequency vibration drilling. The calculate formula of exit burr is achieved after calculate the force of axial and other forces in low frequency vibration drilling, which is also proved the reliability by the experiment. The parameters optimization method is available in order to reduce or mitigate the low frequency axial vibration drilling. It is lay a solid foundation for selecting the reasonable parameters of vibrating drilling process in the theory.

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°.

Abstract: mproving materials surface function by introducing nano/micro surface textures is of great interest in various fields. The authors have also achieved an improvement in the photocatalytic surface function by introducing the microcutting grooves texture on the titanium dioxide surfaces. In this report, the authors performed the vibration assisted cutting to fabricate finer surface microtextures anticipating future usage as microtexture moulds for the nanoimprinting and/or injection moulding. In the experiment, a pure copper plate was cut using a sharply pointed triangular diamond tip vibrated by a fast tool servo system in the direction of cutting depth with μm order amplitude and kHz order frequency. As a result, it was found that the periodical micro concave-convex patterns with the combinations of impressions and pileups can be obtained by the proposed method using almost the same vibration amplitude as the cutting depth. It was also achieved that a micro-textured surface with numerous concave-convex patterns less than 1 μm in height with 3 μm in pitch.

Abstract: High-strength carbon fiber reinforced plastic (CFRP) T800S/250F is used as the large commercial aircraft material for manufacturing the main load-bearing structural components. Drilling is the mostly used in final machining process of CFRP laminates, while the delamination and burrs occur frequently at the drill exit in the CFRP laminate. In this paper, the machinability of T800S/250F was investigated in term of drilling force and hole quality by using a twist drill and a dagger drill. The experimental results indicated that high spindle speed and low feed rate favor the reduction of thrust force for both drill bits. High spindle speed is a preference to gain the good hole quality at drill exit especially for the dagger drill, which also shows excellent drilling performance than the twist drill and was more suitable for drilling of T800S/250F CFRP laminate.

Abstract: The sheet metal bearing cages quality obtained through punching is influenced by a variety of factors related to the punching mechanism construction, to its adjustment onto the press and also to the technological parameters of the punching process itself. This paper refers to an experimental research study applied to a real industrial environment, which analyzes the sheet metal bearing cages obtained through punching. The paper informs about the main results which were obtained during researches regarding the influence of clearances between the active parts of the punching mechanism upon the dimensions of the punched bearing cages windows burrs. The study presents also some information about results interpretation and several related conclusions.

Abstract: With axial position method, In and out cutting point is accurately obtained in separate low frequency axial vibration drilling. So the working angles of the drill, the cutting force and other parameters are accurately calculated during the cutting time in the vibration drilling. The theory calculating formula of the high of the exit burr is derived based on the forming mechanism of the exit burr in drilling. The calculating result of the high of the exit burr is well identical with the experiment result. This research is based for the parameters optimization in low frequency axial vibration drilling.

Abstract: Abstract. Abrasive flow machining (AFM) is an effective method that uses the flow of a pressurized abrasive media for removing workpiece material. It is used to deburring, polishing or radiusing, etc. In this paper, the effect that AFM process on the surface of the helical gear is investigated. Then, the distribution of the velocities, shear rates and shear forces of the abrasive flow on the helical gear surface is obtained by CFD module of the COMSOL Multiphysics software. The simulation results show that the abrasive grains near the addendum, tooth surface and tooth root can be subjected to corresponding shear stress. Experimental results indicated that the surface roughness Ra of the left tooth surface, right tooth surface and addendum before processing 1.429um, 1.108um and 2.732um dropped after processing 0.228um, 0.216um and 1.754um. All burrs at the intersection between tooth surface and end surface has been cleared, the surface quality of the helical gear has been improved. Therefore, AFM method can improve the surface quality of the helical gear effectively.