Experimental Analysis of Ti6Al4V Orthogonal Cutting

2015 ◽  
Vol 665 ◽  
pp. 17-20 ◽  
Author(s):  
Apostolos Korlos ◽  
Orestis Friderikos ◽  
Dimitrios Sagris ◽  
Constantine David ◽  
Gabriel Mansour
Keyword(s):  
Formation Mechanism ◽  
Chip Formation ◽  
Orthogonal Cutting ◽  
Chip Morphology ◽  
Serrated Chip ◽  
Wide Range ◽  
Chip Formation Mechanism ◽  
Serrated Chip Formation ◽  
Chip Geometry ◽  
Cutting Speeds

The chip formation mechanism in orthogonal cutting is a phenomenon that attracts the attention of many researchers. This paper investigates experimentally the orthogonal cutting of Ti6Al4V at different cutting conditions aiming at the understanding of the chip formation mechanism. Serrated chip formation is obtained during orthogonal cutting of Ti6Al4V in a wide range of cutting speeds. The results are analyzed in order to extract useful indices relevant to chip geometry, as the adiabatic zone angle and other dimensions that describe the serrated chip. The cutting forces and the acoustic emission are measured. Finally, by the aid of 3D Computed Tomography (CT) the chip morphology is analyzed to better understand the segmentation process.

FEA Simulation of the Influence of Cutting Parameters on Serrated Chip Formation in Machining Titanium Alloy Ti-6Al-4V

2012 ◽  
Vol 500 ◽  
pp. 152-156
Author(s):  
Zeng Hui Jiang ◽  
Ji Lu Feng ◽  
Xiao Ye Deng
Keyword(s):  
Titanium Alloy ◽  
Chip Formation ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Element Model ◽  
Serrated Chip ◽  
Wide Range ◽  
Serrated Chip Formation ◽  
Fea Simulation

A finite element model of a two dimensional orthogonal cutting process is developed. The simulation uses standard finite software is able to solve complex thermo-mechanical problems. A thermo-visco-plastic model for the machined material and a rigid cutting tool were assumed. One of the main characteristic of titanium alloy is serrated shape for a wide range of cutting conditions. In order to understand the influence of cutting parameters on the chip formation when machining titanium alloy Ti-6Al-4V. The influence of the cutting speed,the cutting depth and the feed on the chip shape giving rise to segmented chips by strain localisation is respectively discussed.

Study of Chip Morphology and Chip Formation Mechanism During Machining of Magnesium-Based Metal Matrix Composites

2017 ◽  
Author(s):  
Brian Davis ◽  
David Dabrow ◽  
Licheng Ju ◽  
Anhai Li ◽  
Chengying Xu ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Formation Mechanism ◽  
Chip Formation ◽  
Metal Matrix ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Matrix Composites ◽  
Particle Type ◽  
Chip Formation Mechanism ◽  
Cutting Speeds

Magnesium (Mg) and its alloys are among the lightest metallic structural materials, making them very attractive for use in the aerospace and automotive industries. Recently, Mg has been used in metal matrix composites (MMCs), demonstrating significant improvements in mechanical performance. However, the machinability of Mg-based MMCs is still largely elusive. In this study, Mg-based MMCs are machined using a wide range of cutting speeds in order to elucidate both the chip morphology and chip formation mechanism. Cutting speed is found to have the most significant influence on both the chip morphology and chip formation mechanism, with the propensity of discontinuous, particle-type chip formation increasing as the cutting speed increases. Saw-tooth chips are found to be the primary chip morphology at low cutting speeds (lower than 0.5 m/s), while discontinuous, particle-type chips prevail at high cutting speeds (higher than 1.0 m/s). Using in situ high speed imaging, the formation of the saw-tooth chip morphology is found to be due to crack initiation at the free surface. However, as the cutting speed (and strain rate) increases, the formation of the discontinuous, particle-type chip morphology is found to be due to crack initiation at the tool tip. In addition, the influences of tool rake angle, particle size, and particle volume fracture are investigated and found to have little effect on the chip morphology and chip formation mechanism.

Study of Chip Morphology and Chip Formation Mechanism During Machining of Magnesium-Based Metal Matrix Composites

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Brian Davis ◽  
David Dabrow ◽  
Licheng Ju ◽  
Anhai Li ◽  
Chengying Xu ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Formation Mechanism ◽  
Chip Formation ◽  
Metal Matrix ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Matrix Composites ◽  
Particle Type ◽  
Chip Formation Mechanism ◽  
Cutting Speeds

Magnesium (Mg) and its alloys are among the lightest metallic structural materials, making them very attractive for use in the aerospace and automotive industries. Recently, Mg has been used in metal matrix composites (MMCs), demonstrating significant improvements in mechanical performance. However, the machinability of Mg-based MMCs is still largely elusive. In this study, Mg-based MMCs are machined using a wide range of cutting speeds in order to elucidate both the chip morphology and chip formation mechanism. Cutting speed is found to have the most significant influence on both the chip morphology and chip formation mechanism, with the propensity of discontinuous, particle-type chip formation increasing as the cutting speed increases. Saw-tooth chips are found to be the primary chip morphology at low cutting speeds (lower than 0.5 m/s), while discontinuous, particle-type chips prevail at high cutting speeds (higher than 1.0 m/s). Using in situ high-speed imaging, the formation of the saw-tooth chip morphology is found to be due to crack initiation at the free surface. However, as the cutting speed (and strain rate) increases, the formation of the discontinuous, particle-type chip morphology is found to be due to crack initiation at the tool tip. In addition, the influences of tool rake angle, particle size, and particle volume fracture are investigated and found to have little effect on the chip morphology and chip formation mechanism.

Experimental and FEM Study of Serrated Chip Formation in High Speed Turning Processes

2011 ◽  
Vol 264-265 ◽  
pp. 1021-1026
Author(s):  
U. Umer ◽  
Li Jing Xie ◽  
Syed Jawid Askari ◽  
S.N. Danish ◽  
S.I. Butt
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Serrated Chip ◽  
High Speed Turning ◽  
Serrated Chip Formation

The finite element method (FEM) has been used to model high speed turning processes with orthogonal cutting conditions. In most of the situations, continuous chip formation is used to analyze the turning process due to its stability and allowing many conditions to simplify the process. However with the increasing applications of high speed turning, serrated chip formation is becoming a more common phenomenon in metal cutting. Serrated chips usually occur in machining of difficult to cut materials at or above a threshold speed. An updated Lagrangian formulation has been used in this study which works with element deletion technique based on a failure criterion. The Johnson Cook strain-hardening thermal-softening material model is used to model serrated chip formation. In addition high speed turning experiments were conducted on AISI H13 tubes using PCBN to analyze serrated chip phenomenon. The chips were analyzed after surface treatment using scanning electron microscope. It has been found that the length of cuts in the chip increases with the cutting speed and the chip changes from serrated to discontinuous. Different process variables like cutting forces, chip morphology, stress, strain and temperature distributions are predicted at different process parameters using FEM. The results show cyclic variation in the cutting forces at high cutting speeds due to varying chip load.

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.

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