Whole process analysis of microstructure evolution during chip formation of high-speed machining OFHC copper

2021 ◽  
Vol 66 ◽  
pp. 470-482
Author(s):  
Hongguang Liu ◽  
Jun Zhang ◽  
Binbin Xu ◽  
Huijie Zhang ◽  
Wanhua Zhao
2020 ◽  
Vol 108 (5-6) ◽  
pp. 1357-1366
Author(s):  
Xiuxuan Yang ◽  
Bi Zhang ◽  
Qian Bai ◽  
Meng Zheng ◽  
Jingang Tang

2017 ◽  
Vol 261 ◽  
pp. 347-353 ◽  
Author(s):  
Walid Jomaa ◽  
Victor Songmene ◽  
Philippe Bocher ◽  
Augustin Gakwaya

Independent research studies have shown notable dissimilarity in the machining behaviour of aluminum alloys AA6061−T6 and AA7075−T651 commonly used in automotive and aeronautical applications. The present work attempts to investigate this dissimilarity based on experimental and numerical data with a focus on chip formation and generated residual stresses under similar high−speed machining (HSM) conditions. The numerical data were calculated by a finite element modeling (FEM) developed using DeformTM 2D software. The results showed that both studied alloys exhibit different chip formation mechanisms and residual stress states at the machined surfaces. On one hand, the AA6061−T6 alloy generates continuous chips and tensile residual stresses whereas the AA7075−T651 alloy produces segmented chips and compressive residual stresses. FEM results showed that the AA6061−T6 alloy generates lower cutting temperature at the tool−chip interface along with higher equivalent total strains at the machined surface as compared to the AA7075−T651 alloy. Based on the experimental and numerical results, it was pointed out that the differences in terms of thermal conductivity and initial yield stress are the main reasons explaining the dissimilarity observed.


1995 ◽  
Vol 54 (1-4) ◽  
pp. 82-87 ◽  
Author(s):  
I.F. Dagiloke ◽  
A. Kaldos ◽  
S. Douglas ◽  
B. Mills

2012 ◽  
Vol 565 ◽  
pp. 484-489
Author(s):  
Bing Wang ◽  
Zhan Qiang Liu ◽  
Qi Biao Yang

Analyzing mechanism of the chip formation is a significant way to understand the metal cutting process better. The characterization of serrated chip formation in high speed machining of hardened AISI1045 steel is investigated with the aid of optical microscopy and micro-hardness measurement in this paper. The chip morphology evolving from continuous one to serrated one with the cutting speed increasing from 100-1500m/min is observed. Compared with the continuous chip pattern, serrated chip has its particular characterization parameters. The characteristics of serration degree and the segmentation frequency of the serrated chip are presented. The micro-hardness at the adiabatic shear band of serrated chip is then measured. The results show that the serration degree and segmentation frequency of serrated chip have a tendency of enhancement with the cutting speed increasing. The micro-hardness along the adiabatic shear band increases with the cutting speed increasing due to severe strain hardening. With a critical speed at about 100-200m/min, micro-hardness decreases from the tool-chip interface to the free surface of the chip.


2016 ◽  
Vol 86 (5-8) ◽  
pp. 1201-1206 ◽  
Author(s):  
Qibiao Yang ◽  
Yin Wu ◽  
Dun Liu ◽  
Lie Chen ◽  
Deyuan Lou ◽  
...  

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Binbin Xu ◽  
Jun Zhang ◽  
Hongguang Liu ◽  
Xiang Xu ◽  
Wanhua Zhao

Abstract Difficult-to-cut materials are widely used in aerospace and other industries. Titanium alloys are the most popular ones among them due to their high strength-to-weight ratio and high temperature resistance. However, in high-speed machining, the alloys are prone to produce serrated chips, which have a serious influence on surface integrity. In this study, a coupled Eulerian–Lagrangian method is used to simulate the orthogonal cutting of Ti6Al4V due to its advantages of avoiding element distortion and improving the data extraction efficiency. The internal relationship between serrated chip formation and periodic profile of machined surfaces is analyzed by the simulation results and experimental data which are obtained by optical microscope and white light interferometer. Furthermore, thermal–mechanical loads on machined surfaces are reconstructed based on the simulation results, and a coupled finite element and cellular automata approach is used to describe the dynamic recrystallization process within the area of the machined surface during the formation of a single serration. According to the results, the periodic fluctuation of cutting forces is attributed to the serrated chip formation phenomenon, which then leads to the periodic profile of machined surfaces. The period is about 60–70 µm, and its amplitude decreases with the increase of cutting speeds. Moreover, the loads on machined surfaces also show the same period due to serrated chip formation. As a result, the grain refinement layer thickness (about 2 ∼ 5 µm) in machined surfaces is related to the surface temperature and exhibits the same periodic characteristics along the cutting direction.


1963 ◽  
Vol 85 (4) ◽  
pp. 365-372 ◽  
Author(s):  
K. J. Trigger ◽  
B. F. von Turkovich

This paper presents metal-cutting data for the high-speed machining of copper and aluminum, each at two levels of purity, and over a range of workpiece temperatures from −326 deg F (80 deg K) to 550 deg F (560 deg K). It has been found that cutting behavior is influenced by purity of work material, its initial temperature, and extent of tool-chip contact. The influence of plastic deformation on chip hardness has been found to be intimately associated with the purity of the work material.


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