scholarly journals Study on Chip Formation in Grinding of Nickel-Based Polycrystalline Superalloy GH4169

2021 ◽  
Author(s):  
Tao Zhu ◽  
Ming Cai ◽  
Yadong Gong ◽  
Xingjun Gao ◽  
Ning Yu ◽  
...  
Keyword(s):  
Finite Element ◽  
Chip Formation ◽  
Morphological Evolution ◽  
Chip Morphology ◽  
Grinding Process ◽  
Cutting Depth ◽  
Serrated Chip ◽  
Nickel Based Superalloy ◽  
Grinding Speed ◽  
On Chip

Abstract Based on the variation of the actual cutting depth during the grinding process, a 3D finite element (FE) simulation model for grinding nickel-based superalloy GH4169 with single abrasive was initially constructed. Then the morphological evolution of the grinding chips during the grinding process was studied. In addition, the effect of the single abrasive cutting depth and the grinding speed on chip morphology and segmentation frequency was investigated. Finally, experimental results with the same test parameters verify the finite element simulation results. The results showed that in the experimental grinding speed range, the sawtooth lamellar chip with the free surface being serrated and the contact surface being smooth due to the extrusion of the abrasive is easy to produce when grinding nickel-based superalloy GH4169. As the grinding speed increases, the chip morphology changes from a unitary lamellar chip to a continuous serrated chip, developing into a continuous ribbon chip. The chip segmentation frequency is mainly determined by grinding depth and grinding speed. To be specific, the smaller the grinding depth and the greater the grinding speed, the greater the chip formation frequency.

Investigation of Chip Morphology in High-Speed Milling of Nickel-Based Superalloy GH706

2014 ◽  
Vol 800-801 ◽  
pp. 113-118
Author(s):  
Sheng Lei Xiao ◽  
Xian Li Liu ◽  
Yu Wang ◽  
Kai Li
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Adiabatic Shear ◽  
Shear Instability ◽  
Serrated Chip ◽  
High Speed Milling ◽  
Nickel Based Superalloy ◽  
Serrated Chip Formation

This paper analyzed the serrated chip formation process and mechanism in high-speed milling of nickel-based superalloy GH706. Firstly, analyzed two theories of serrated chip formation: cyclical fracture theory and adiabatic shear theory. Secondly, used the simulation of chip formation in high-speed milling of GH706 process, and concluded that the two major theories have achieved dialectical unity when machining for such difficult machining materials. Finally experiments for serrated chip, when cutting speed exceeded 200/min, serrated chips became more obvious. Research has shown that for nickel-based superalloy, adiabatic shear instability of the unstable thermoplastic in the first deformation zoon become the leader of formation of serrated chip, followed as the speed increases, fracture aggravate the degree of serrated chip.

A FEM Study on Chip Formation in Orthogonal Turning Nickel-Based Superalloy GH80A

2008 ◽  
Vol 575-578 ◽  
pp. 1370-1375 ◽  
Author(s):  
Jun Li Li ◽  
Gang Liu ◽  
Dong Jin Zhang ◽  
Ming Chen
Keyword(s):  
Finite Element ◽  
Chip Formation ◽  
Cutting Parameters ◽  
Machining Process ◽  
High Yield ◽  
Nickel Based Superalloy ◽  
Lagrangian Finite Element ◽  
Element Approach ◽  
Material Constitutive Relation ◽  
On Chip

The nickel-based superalloy GH80A is a typical difficult-to-cut material. It has been used in a good many kinds of aeronautical key structures because of its high yield stress and anti-fatigue performance at high temperature. But selection of cutting parameters in actual machining process mainly depends on experience and lacks of scientific utterance. In this paper, finite element method (FEM) was introduced to study the chip formation process when machining nickel-based superalloy GH80A. By the way of lagrangian finite element approach and material failure, adiabatic shear band (ASB) and periodic fracture were simulated with the help of former researchers’ studies on the material constitutive relation. Both the mechanism of adiabatic shearing phenomenon at primary shear zone and periodic crack in the free surface were analyzed, chip formations under different cutting parameters were got and compared carefully. The root cause of saw-tooth chip formation under different cutting speeds was discussed.

Serrated Chip Morphology and Comparison With Finite Element Simulations

2004 ◽  
Author(s):  
L. Deshayes ◽  
T. Mabrouki ◽  
R. Ivester ◽  
J.-F. Rigal
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Chip Formation ◽  
Orthogonal Cutting ◽  
Chip Morphology ◽  
Metallographic Analysis ◽  
Machining Processes ◽  
Serrated Chip ◽  
Finite Element Software ◽  
Physical Phenomena

The complexity of chip formation in machining processes stems from the confluence of several physical phenomena — mechanical, thermal, and chemical — occurring at very high strain rate. The prediction of chip morphology depends on a fundamental understanding of these phenomena and is of industrial importance for cutting force prediction and surface integrity control. Our paper focuses on characterizing the chip morphology of serrated-chip (saw-tooth shape chip) and discusses the physical phenomena accompanying the serrated-chip formation according to finite element modeling (FEM) simulations. The paper presents a bibliographic review and an experimental study of chip formation. The experimental study, based on metallographic analysis of chip morphology and hardness measurements, focuses on machining of American Iron and Steel Institute (AISI) 4340 steel alloy. Two finite element software packages were used to simulate chip formation under orthogonal cutting conditions. The FEM results are compared with the hardness measurements, and the chip morphology characterization method used to support the simulations is discussed.

Study of the Effect of Tool Wear on Cutting Ti6Al4V Process

2013 ◽  
Vol 690-693 ◽  
pp. 2030-2035
Author(s):  
Shu Bao Yang ◽  
Hong Chao Ni ◽  
Guo Hui Zhu
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Key Factors ◽  
Serrated Chip ◽  
Comprehensive Properties ◽  
Commercial Applications ◽  
On Chip ◽  
Rapid Tool

Ti6Al4V alloy is widely used in the aircraft industry, marine and the commercial applications due to its excellent comprehensive properties. However, its poor machinability prevents it from application widely, and the rapid tool wear is one of the key factors. The FEM models of cutting titanium alloy are established. The effect of tool wear on chip morphology, cutting temperature and cutting force are studied. The simulation results show that: the cutting force and cutting temperature will rise with the increase of tool wear. Furthermore, the degree of chip deformation will improve, but the frequency of serrated chip tooth occurred will decrease.

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
Keyword(s):  
Finite Element ◽  
Chip Formation ◽  
Defect Formation ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Rake Angle ◽  
Critical Transition ◽  
Cutting Depth ◽  
Edge Defect ◽  
Edge Defects

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.

Experimental and numerical study of chip formation during straight turning of hardened AISI 4340 steel

2005 ◽  
Vol 219 (7) ◽  
pp. 515-524 ◽  
Author(s):  
S Belhadi ◽  
T Mabrouki ◽  
J-F Rigal ◽  
L Boulanouar
Keyword(s):  
Chip Formation ◽  
Numerical Study ◽  
Chip Morphology ◽  
Effect Of Temperature ◽  
Serrated Chip ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Sawtooth Chip ◽  
Coated Carbide ◽  
Aisi 4340

The present paper is a contribution to the investigation of physical phenomena accompanying sawtooth chip formation in the case of hard turning. The study concerns the machining with coated carbide of tempered AISI 4340 steel with a Rockwell C hardness of 47 HRC. The main idea in this paper deals with the establishment of a direct relationship between serrated-chip morphology simultaneously with force component signals derived from acquisition at high frequency and with the width of facets detected on a workpiece machined surface. This experimental work was supported by a numerical simulation based on Abaqus/ Explicit software. Numerical results dealing with effect of temperature evolution on the chip morphology show that the beginning of the sawtooth chip initiation is due to an adiabatic shear at the tool tip with propagation pathway towards the free surface. In addition, computed results have a good corroboration with those obtained experimentally.

Finite Element Investigation of the Influence of Thermophysical Parameters on Segmented Chip Formation during High Speed Cutting

2011 ◽  
Vol 130-134 ◽  
pp. 2817-2821
Author(s):  
You Xi Lin ◽  
Cong Ming Yan
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Specific Heat ◽  
Chip Formation ◽  
High Speed ◽  
Element Model ◽  
Serrated Chip ◽  
High Speed Cutting ◽  
Thermophysical Parameters ◽  
Serrated Chip Formation

A 2D fully thermal mechanical coupled finite element model is applied to study the influence of material parameters on serrate chip formation during high speed cutting process. The serrated chip formation during high speed machining was predicted. Of interests are the effects of thermal conductivity, specific heat and density. Results showed significant influence of these thermophysical parameters on the serrated chip phenomena, especially in the case of the density. Increasing thermal conductivity specific heat and density lead to a decreasing degree of segmentation. The influence of the thermal conductivity on the cutting force and the specific heat on maximum temperatures in the shear band is also discussed.

Investigation on Chip Formation during Machining Using Finite Element Modeling

2012 ◽  
Vol 505 ◽  
pp. 31-36 ◽  
Author(s):  
Moaz H. Ali ◽  
Basim A. Khidhir ◽  
Bashir Mohamed ◽  
A.A. Oshkour
Keyword(s):  
Finite Element ◽  
Tool Wear ◽  
Finite Element Modeling ◽  
Chip Formation ◽  
Cutting Tool ◽  
Chip Morphology ◽  
Machining Process ◽  
Element Modeling ◽  
Segmented Chip ◽  
Cutting Speeds

Titanium alloys are desirable materials for aerospace industry because of their excellent combination of high specific strength, lightweight, fracture resistant characteristics, and general corrosion resistance. Therefore, the chip morphology is very important in the study of machinability of metals as well as the study of cutting tool wear. The chips are generally classified into four groups: continuous chips, chips with built-up-edges (BUE), discontinuous chips and serrated chips. . The chip morphology and segmentation play a predominant role in determining machinability and tool wear during the machining process. The mechanics of segmented chip formation during orthogonal cutting of titanium alloy Ti–6Al–4V are studied in detail with the aid of high-speed imaging of the chip formation zone. The finite element model of chip formation of Ti–6Al–4V is suggested as a discontinuous type chip at lower cutting speeds developing into a continuous, but segmented, chip at higher cutting speeds. The prediction by using finite-element modeling method and simulation process in machining while create chips formation can contribute in reducing the cost of manufacturing in terms of prolongs the cutting tool life and machining time saving.

Research on Adiabatic Shear during Serrated Chip Formation of High Speed Turning of Hardened Steel

2010 ◽  
Vol 139-141 ◽  
pp. 743-747
Author(s):  
Chun Zheng Duan ◽  
Hai Yang Yu ◽  
Min Jie Wang ◽  
Bing Yan ◽  
Yu Jun Cai
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Rake Angle ◽  
Adiabatic Shear ◽  
Cutting Condition ◽  
Serrated Chip ◽  
Serrated Chip Formation

The development of chip morphology, critical cutting condition of adiabatic shear during serrated chip formation and cutting forces were observed and measured by high speed turning experiment for 30CrNi3MoV hardened steel. Results show that the cutting speed and rake angle are leading factors to influence chip morphology and cutting forces. With the increase of cutting speed, the continuous band chip transforms into serrated chip at a certain critical value. As the rake angle is changed from positive to negative, the critical cutting speed of adiabatic shear significantly decreases, the cutting forces abruptly reduces when the serrated chip forms. The results from predicting critical cutting speed using the critical cutting condition criterion of adiabatic shear in metal cutting process show that the leading reason of serrated chip formation is that the adiabatic shear fracture repeatedly occurs in the primary shear zone.

Theoretical Analysis of Serrated Chip Formation Based on Ideal Models in High Speed Cutting

2010 ◽  
Vol 154-155 ◽  
pp. 239-245
Author(s):  
Chong Yang Gao ◽  
Bin Fang ◽  
Yuan Tong Gu
Keyword(s):  
Chip Formation ◽  
High Speed ◽  
Engineering Application ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Formation Model ◽  
Serrated Chip ◽  
Serrated Chip Formation ◽  
Serrated Chips ◽  
The Ideal

In this paper, two ideal formation models of serrated chips, the symmetric formation model and the unilateral right-angle formation model, have been established for the first time. Based on the ideal models and related adiabatic shear theory of serrated chip formation, the theoretical relationship among average tooth pitch, average tooth height and chip thickness are obtained. Further, the theoretical relation of the passivation coefficient of chip’s sawtooth and the chip thickness compression ratio is deduced as well. The comparison between these theoretical prediction curves and experimental data shows good agreement, which well validates the robustness of the ideal chip formation models and the correctness of the theoretical deducing analysis. The proposed ideal models may have provided a simple but effective theoretical basis for succeeding research on serrated chip morphology. Finally, the influences of most principal cutting factors on serrated chip formation are discussed on the basis of a series of finite element simulation results for practical advices of controlling serrated chips in engineering application.

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