Finite Element Modeling of Orthogonal Cutting of Pyrolytic Carbon

Author(s):  
Gautam Salhotra ◽  
Vivek Bajpai ◽  
Ramesh K. Singh

Engineered features on pyrolytic carbon (PyC) have been demonstrated as an approach to improve the flow hemodynamics of the cardiovascular implants. In addition, it also finds application in thermonuclear components. These micro/meso scale engineered features are required to be machined onto the PyC leaflet. However, being a layered anisotropic material and brittle in nature, its machining characteristics differ from plastically deformable isotropic materials. Consequently, this study is aimed at creating a finite element model to understand the mechanics of material removal in the plane of transverse isotropy (horizontally stacked laminae) of PyC. A layered model approach has been used to capture the interlaminar shearing and brittle fracture during machining. A cohesive element layer has been used between the chip layer and the machined surface layer. The chip layer and workpiece are connected through a cohesive layer. The model predicts cutting forces and the chip length for different cutting conditions. The orthogonal cutting model has been validated against experimental data for different cutting conditions for cutting and thrust forces. Parametric studies have also been performed to understand effect of machining parameters on machining responses. This model also predicts chip lengths which have also been compared with the actual chip morphology obtained from microgrooving experiments. The prediction errors for cutting force and chip length are within 20% and 33%, respectively.

2006 ◽  
Vol 315-316 ◽  
pp. 140-144 ◽  
Author(s):  
Su Yu Wang ◽  
Xing Ai ◽  
Jun Zhao ◽  
Z.J. Lv

An orthogonal cutting model was presented to simulate high-speed machining (HSM) process based on metal cutting theory and finite element method (FEM). The residual stresses in the machined surface layer were obtained with various cutting speeds using finite element simulation. The variations of residual stresses in the cutting direction and beneath the workpiece surface were studied. It is shown that the thermal load produced at higher cutting speed is the primary factor affecting the residual stress in the machined surface layer.


2019 ◽  
Vol 11 (4) ◽  
pp. 107-121 ◽  
Author(s):  
Chinmaya PADHY ◽  
Pariniti SINGH

Minimum quantity lubrication (MQL) is currently a widely used lubricating technique during machining, in which minimum amount of lubricant in the form of mist is delivered to the machining interface, thus helps to reduce the negative effects caused to the environment and human health. Further, to enhance the productivity of machining process specifically for hard-to-cut materials, nano cutting fluid (suitably mixed nano materials with conventional cutting fluid) is used as an alternative method to conventional lubrication (wet) in MQL. In this study, h-BN nano cutting fluid was formulated with 0.1% vol. concentration of h-BN in conventional cutting fluid (Servo- ‘S’) for NCF-MQL technique and its tribological behaviors on machining(turning) performance of Inconel 625 were studied and compared with other lubricating conditions (dry, wet, MQL conventional). The tribological effects were analyzed in terms of tool wear analysis, chip morphology along with statistical analysis for machined surface and evolved cutting forces during machining. The optimal input machining parameters for experiments were defined by the use of Taguchi and Grey relational based multi response optimization technique. Finally, the tribological study shows that the use of h-BN NCF-MQL is a viable and sustainable option for improving machining performance of hard- to- cut material like Inconel 625.


2010 ◽  
Vol 154-155 ◽  
pp. 794-805 ◽  
Author(s):  
Yao Jang Lin ◽  
Yan Cherng Lin ◽  
A Cheng Wang ◽  
Der An Wang ◽  
Han Ming Chow

This study investigates the feasibility of EDM for processing ZrO2 and Al2O3 of non-conductive ceramics, which were covered by an assisted conductive material, an adherent copper foil, on the workpiece surface. The conductive material adhered on the surface of the non-conductive ceramics would induce a series of electrical discharges between the tool electrode and the workpiece in the initial stage of the EDM process. Thus, the pyrolytic carbon that cracked from kerosene was formed and deposited on the machined surface to maintain the progress of EDM. In this work, the essential EDM machining parameters were varied to determine the effects on material removal rate (MRR), electrode wear rate (EWR), and surface roughness. The stability of EDM progress and the surface integrities of ZrO2 and Al2O3 machined by EDM were also investigated. The aim of this study is to explore the feasibility and development of an applicable process for processing non-conductive ceramics through EDM. Moreover, the exploitation of this work can be applied to industrial applications and used to develop machining techniques for non-conductive ceramics.


Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  

Abstract High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.


2016 ◽  
Vol 693 ◽  
pp. 1221-1227 ◽  
Author(s):  
Zhen Xi Jiang ◽  
Jie Sun ◽  
Jian Feng Li

The existing end mill is hard to balance the tool rigidity, heat dissipation and chip evacuation. In this study, the geometries of groove and micro-blade of the end mill machining titanium are optimized, through imitating the corn leaf’s tooth based on bionics. The peripheral cutting edge is composed of linear first rake, parabolic second rake and rear face. The chip-hold groove is composed of parabolic main groove and cubic curve vice groove. The cutting process of straight tooth and designed composite tooth are simulated by constructing the two-dimensional orthogonal cutting model using ABAQUS. The results show that: compared to the straight tooth, the designed composite tooth inhibits the generation of serrated chip, and the fluctuations of cutting force are smaller, the squeezing effect on the machined surface is weaker.


2020 ◽  
Vol 978 ◽  
pp. 106-113
Author(s):  
Marimuthu K. Prakash ◽  
Kumar C.S. Chethan ◽  
Prasada H.P. Thirtha

Machining has been one of the most sort of process for realizing different products. It has significant role in the value additions process. Machining is one of the production process where material is removed from the parent material to realize the final part or component. Among machining, the well known machining processes are turning, milling, shaping, grinding and non-conventional machining processes like electric discharge machining, ultrasonic machining, chemical machining etc. The fundamental of all these processes being material removal in the form of chips using a tool either in contact or not in contact. In the present work, milling is being taken for study Finite element analysis is being used as a tool to understand the different phenomenon that underlies the machining processes. Of late, the machining induced residual stresses is of great interest to the researchers since the residual stresses have an impact on the functional performances. The present work is to model the milling process to predict the forces and residual stresses using finite element method. Unlike many researchers, the authors have attempted to develop oblique cutting model rather than an orthogonal cutting model. The present work was carried out on AISI 1045 steel.


2012 ◽  
Vol 268-270 ◽  
pp. 422-425
Author(s):  
Mu Lan Wang ◽  
Jun Ming Hou ◽  
Bao Sheng Wang ◽  
Wen Zheng Ding

The application of Finite Element Method (FEM) in cutting force model for Aluminium alloy work-piece is useful to reduce the production costs and shorten the experimental period. Firstly, the theoretical model of the orthogonal cutting and the oblique cutting are analyzed in this paper. And then, the corresponding finite element models are theoretically constructed. By comparing the results, the following conclusions are drawn: with the increase of the cutting thickness, the cutting force increasing is in an enhancement tendency. The oblique cutting model of overall tool is more conductive to the subsequent runout and the flutter analysis.


Author(s):  
A.P. Markopoulos ◽  
K. Kantzavelos ◽  
N.I. Galanis ◽  
D.E. Manolakos

This paper presents simulation of High Speed Machining of steel with coated carbide tools. More specifically, Third Wave Systems AdvantEdge commercial Finite Element Method code is employed in order to present turning models, under various machining conditions. As a novelty, the proposed models for High Speed Machining of steel are three-dimensional and are able to provide predictions on cutting forces, tool and workpiece temperatures, chip formation, and chip morphology. Model validation is achieved through experimental work carried out under the same conditions as the ones used in modeling. For the experimental work, the principles for design of experiment were used in order to minimize the required amount of experiments and obtain useful results at the same time. Furthermore, a Taguchi analysis is carried out based on the results. The analysis indicates that there is a good agreement between experiment and modeling, and the proposed models can be further employed for the prediction of a range of machining parameters, under similar conditions.


2012 ◽  
Vol 499 ◽  
pp. 208-212
Author(s):  
Ai Hua Gao ◽  
Fu Rong Wang ◽  
Jian Xin Zhang

The paper make the service life of relieving formed milling cutter as the optimization objective, proceed the simulation study on the mechanical degree of cutter, cutting data. The concrete method is that the orthogonal milling model is established to simulate the simulation milling process, some basic parameters which are obtained in the machining process are analyzed and discussed. The results indicate that the finite element simulation of the metal cutting processing can analyze quantitatively some physical properties, such as the cutting force, stress, strain and so on, the traditional way of qualitative analysis is changed. The state of machining is in favour of grasping in the theory, the theory and technology are provided to establish the proper processing technology strategy.


2013 ◽  
Vol 589-590 ◽  
pp. 111-116
Author(s):  
Tao Wang ◽  
Li Jing Xie ◽  
Xi Bin Wang

The aim of this paper is to compare the predicting ability of the orthogonal cutting models developed by three commonly used finite element softwares, namely commercial explicit dynamic code Abaqus/explicit, Thirdwave AdvantEdge and implicit finite element codes Deform 2D. In all proposed models, the chip formation was simulated through adaptive remeshing and plastic flow of work material around the round edge of the cutting tool. Therefore, there was no need for a chip separation criterion which made the physical process simulation more realistically. Predicted cutting, feed force and shear angle were compared with experimental results. In addition, the effect of friction coefficient on the chip morphology was investigated as well.


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