Finite Element and Experimental Analysis of Edge Defects Formation during Orthogonal Cutting of SiCp/Al Composites

2012 ◽  
Vol 500 ◽  
pp. 146-151 ◽  
Author(s):  
Ning Hou ◽  
Li Zhou ◽  
Shu Tao Huang ◽  
Li Fu Xu

In this paper, a finite element method was used to dynamically simulate the process of the edge defects formation during orthogonal cutting SiCp/Al composites. The influence of the cutting speed, cutting depth and rake angle of the PCD insert on the size of the edge defects have been investigated by using scanning electron. According to the simulated results, it can be provided that the cutting layer material has an effect on transfer stress and hinder the chip formation in the critical transition stage, and the critical transition point and distance are defined in this stage. The negative shear phenomenon is found when the chip transit to the edge defects in the flexure deformation stage, so the process of the chip formation is the basis of the edge defects formation. In addition, the relationship between the nucleation and propagation direction of the crack and the variation of the edge defect shape on the workpiece was investigated by theory, and it found that the negative shear angle formation is the primary cause of the edge defect formation. A mixed mode crack is found in the crack propagation stage. The sizes of edge defects were measured by the experiment and simulation, and the edge defect size decrease with the increasing of tool rake angle, while increase with increasing cutting depth and cutting speed.

2012 ◽  
Vol 723 ◽  
pp. 326-331
Author(s):  
De Jin Zou ◽  
Shu Tao Huang ◽  
Li Zhou ◽  
Li Fu Xu ◽  
Ning Hou ◽  
...  

In this paper, the influence of the tool rake angle, cutting depth and cutting speed on exit edge defect sizes are discussed by the two dimension cutting experiment of SiCp/Al composites. The sizes are measured by using the Keyence VHX-1000C type super preview 3D microscopy. The results indicate that exit edge defect sizes are influenced greatly by tool rake angle and cutting depth, and are influenced slightly by the cutting speed. The edge defect sizes have an overall downward trend when the tool rake angle is smaller than 5°, and have an apparent upward trend when the tool rake angle (γ0) is 10°.The length (L), height (H) of exit edge defects and the negative shear angle increase with increasing of the cutting depth.


2011 ◽  
Vol 223 ◽  
pp. 764-773 ◽  
Author(s):  
Hans Werner Hoffmeister ◽  
Arne Gerdes

Several authors have previously simulated chip formation and their behaviour at the orthogonal cutting process. In contrast the chip formation for grinding was less investigated. This paper introduces a quick-stop device which allows easy investigation of the chip formation for the grinding process. For this process a workpiece forced by compressed air is shot against a single grain diamond with a large negative rake angle. Cutting forces were measured with a piezo electric sensor and discussed for a cutting speed range from 10m/s up to 30m/s. In Abaqus/Explicit a lagrangian formulation based finite element model was built to describe the chip formation for the grinding process. Chip formation, stress and heat distribution in the workpiece material can be calculated by this simulation model. The material behaviour was described with the Johnson Cook law. The simulation results show a good correlation compared to the quick stop experiments. All in all this simulation leads to a better understanding of the chip formation during grinding.


2011 ◽  
Vol 188 ◽  
pp. 110-115
Author(s):  
Guo He Li ◽  
Min Jie Wang

Orthogonal cutting experiments of Fe-36Ni invar alloy are performed to investigate the influence of cutting conditons on adiabtic shear, which occurs in the process of chip formation of many materials. It is found that the cutting speed, cutting depth and rake angle all have influence on adiabatic shear and there is a critical cutting speed at which the adiabatic shear appears. By metallurgical observation, the critical cutting speed under different cutting depth and rake angles are given. A model based on linear pertubation analysis is used to predict the adiabatic shear critical ctting conditions of Fe-36Ni invar alloy. The comparison of prediction results and that of expriments shows that this prediction model is available.


1984 ◽  
Vol 30 (104) ◽  
pp. 77-81 ◽  
Author(s):  
D.K. Lieu ◽  
C.D. Mote

AbstractThe cutting force components and the cutting moment on the cutting tool were measured during the orthogonal machining of ice with cutting tools inclined at negative rake angles. The variables included the cutting depth (< 1 mm), the cutting speed (0.01 ms−1to 1 ms−1), and the rake angles (–15° to –60°). Results of the experiments showed that the cutting force components were approximately independent of cutting speed. The resultant cutting force on the tool was in a direction approximately normal to the cutting face of the tool. The magnitude of the resultant force increased with the negative rake angle. Photographs of ice-chip formation revealed continuous and segmented chips at different cutting depths.


2003 ◽  
Vol 125 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Y. Ohbuchi ◽  
T. Obikawa

A thermo-elastic-plastic finite element modeling of orthogonal cutting with a large negative rake angle has been developed to understand the mechanism and thermal aspects of grinding. A stagnant chip material ahead of the tool tip, which is always observed with large negative rake angles, is assumed to act like a stable built-up edge. Serrated chips, one of typical shapes of chips observed in single grain grinding experiment, form when analyzing the machining of 0.93%C carbon steel SK-5 with a rake angle of minus forty five or minus sixty degrees. There appear high and low temperature zones alternately according to severe and mild shear in the primary shear zone respectively. The shapes of chips depend strongly on the cutting speed and undeformed chip thickness; as the cutting speed or the undeformed chip thickness decreases, chip shape changes from a serrated type to a bulging one to a wavy or flow type. Therefore, there exists the critical cutting speed over which a chip can form and flow along a rake face for a given large negative rake angle and undeformed chip thickness.


2011 ◽  
Vol 305 ◽  
pp. 198-201
Author(s):  
Guo He Li ◽  
Hou Jun Qi ◽  
Bing Yan

Orthogonal cutting experiments of Fe-36Ni invar alloy are performed. The change of chip morphology with cutting conditions are investigated through metallurgical observation, and the critical cutting speed of adiabatic shear for Fe-36Ni invar alloy at different cutting depths and rake angles are given. In addition, the characteristic of chip deformation before the occurrence of adiabatic shear is also analyzed. The results show that the critical cutting speed decreases with the increase of cutting depth and hardness, but increases with the increase of rake angle. The deformation coefficient tends to a constant value with the increase of cutting speed.


2016 ◽  
Vol 679 ◽  
pp. 27-32
Author(s):  
Shi Jun Ji ◽  
Lei Lei Liu ◽  
Ji Zhao ◽  
Jin Chao Li

Silicon carbide, a high-strength material, has a ductile-brittle transition mechanism. In order to establish a reasonable silicon carbide abrasive belt grinding parameters to obtain high precision silicon carbide free-surface efficiently, a series of finite element simulations were conducted to comprehend the single point diamond grinding of silicon carbide using professional analysis software of nonlinear finite element in this paper. According to the differences of cutting parameter, such as cutting depth, cutting deformation of the chip and the maximum cutting force were studied. For the free-form surface with higher accuracy, the data showed that ductile machining of silicon carbide is more efficient along with the larger rake angle, the higher cutting speed and the smaller cutting depth.


2011 ◽  
Vol 383-390 ◽  
pp. 1915-1920
Author(s):  
Guo He Li ◽  
Bing Yan ◽  
Yu Jun Cai

Orthogonal cutting experiments of hardness AISI1045 steel( HRC45) are performed. The change of chip formation and cutting force with cutting conditions are investigated through metallurgical observation, and the critical cutting speed of adiabatic shear of AISI1045 steel at different cutting depths and rake angles are given. In addition, the saw-frequency and space length of serrated chip and the influence of serrated chip on cutting force are also studied. The critical cutting speed decreases with the increase of cutting depth, but increases with the increase of rake angle. The saw-frequency of serrated chip is found to be independent of the cutting depth, and increases with the increase of cutting speed and rake angle. The cutting force decreases with the increase of cutting speed and rake angle, but increases with the increase of cutting depth, and there isn’t a sudden change of cutting force at the onset of adiabatic shear.


2014 ◽  
Vol 474 ◽  
pp. 192-199 ◽  
Author(s):  
Ladislav Kandráč ◽  
Ildikó Maňková ◽  
Marek Vrabel' ◽  
Jozef Beňo

In this paper, a Lagrangian finite element-based machining model is applied in the simulation of cutting forces in two-dimensional orthogonal cutting of titanium Ti-6Al-4V alloy. The simulations were conducted using 2D Finite Element Method (FEM) machining simulation software. In addition, the cutting experiments were carried out under the different cutting speed, feed and tool geometry (rake angle, clearance angle and cutting edge radius). The effect of cutting speed, feed and tool geometry on cutting force were investigated. The results obtained from the finite element method (FEM) and experimental studies were compared.


1984 ◽  
Vol 30 (104) ◽  
pp. 77-81 ◽  
Author(s):  
D.K. Lieu ◽  
C.D. Mote

AbstractThe cutting force components and the cutting moment on the cutting tool were measured during the orthogonal machining of ice with cutting tools inclined at negative rake angles. The variables included the cutting depth (< 1 mm), the cutting speed (0.01 ms−1 to 1 ms−1), and the rake angles (–15° to –60°). Results of the experiments showed that the cutting force components were approximately independent of cutting speed. The resultant cutting force on the tool was in a direction approximately normal to the cutting face of the tool. The magnitude of the resultant force increased with the negative rake angle. Photographs of ice-chip formation revealed continuous and segmented chips at different cutting depths.


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