Effect of Microstructure on Cutting Force and Chip Formation during Machining of Ti-6Al-4V Alloy

2013 ◽  
Vol 690-693 ◽  
pp. 2437-2441 ◽  
Author(s):  
Shou Jin Sun ◽  
Milan Brandt ◽  
John P.T. Mo
Keyword(s):  
Cutting Force ◽  
Chip Formation ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Lamellar Microstructure ◽  
Chip Morphology ◽  
Dry Machining ◽  
Segmented Chip ◽  
Different Types ◽  
Fully Lamellar

Dry machining was conducted on Ti-6Al-4V alloy with three different types of microstructure: globular, bi-modal and fully lamellar microstructures. The effects of cutting speed on the cutting force and chip formation were investigated. The differences in cutting force and chip morphology are found only at cutting speed lower than 100m/min. The main cutting force and chip thickness when machining Ti-6Al-4V alloy with globular microstructure are lower than these when cutting Ti-6Al-4V alloy with bi-modal and fully lamellar microstructures at cutting speed lower than 100m/min. The tendency of segmented chip formation is the highest for cutting Ti-6Al-4V alloy with fully lamellar microstructure and the lowest for machining Ti-6Al-4V alloy with bi-modal microstructure at cutting speed lower than 100m/min because of their differences in increase of shear strength with strain rate.

Evaluation of micro-features of chips of Inconel 825 during dry turning with uncoated and chemical vapour deposition multilayer coated tools

2016 ◽  
Vol 232 (6) ◽  
pp. 979-994 ◽  
Author(s):  
A Thakur ◽  
S Gangopadhyay
Keyword(s):  
Shear Band ◽  
Chemical Vapour Deposition ◽  
Chip Formation ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Dry Machining ◽  
Research Attention ◽  
Inconel 825

Mechanism of chip formation during dry machining of Ni-based super alloys needs considerable research attention as it directly or indirectly affects different aspects of machinability. Therefore, the present research work aims at understanding the mechanism of chip formation with the help of various chip characteristics during dry machining of Inconel 825, a nickel-based super alloy. The influence of multilayer coating deposited using chemical vapour deposition, cutting speed and machining duration has been investigated on types and form of chips, along with different characteristics of chip like shear band thickness, saw-tooth distance, equivalent chip thickness, saw-tooth angle and chip segmentation frequency. Chip–tool contact length, hardness and crystallographic orientation (through X-ray diffraction) of chip have also been studied. Furthermore, different machining characteristics such as cutting force, apparent coefficient of friction and cutting temperature have also been determined for explaining the mechanism of various aspects of chip formation. The results indicated that coated tool restricted sharp increase in shear band thickness with cutting speed and resulted in reduction in saw-tooth distance, saw-tooth angle, equivalent chip thickness, chip hardness and deformation on grains while exhibiting increase in chip segmentation frequency in comparison with its uncoated counterpart.

scholarly journals Experiments in the Machining of Ice at Negative Rake Angles

1984 ◽  
Vol 30 (104) ◽  
pp. 77-81 ◽  
Author(s):  
D.K. Lieu ◽  
C.D. Mote
Keyword(s):  
Cutting Force ◽  
Chip Formation ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Rake Angle ◽  
Cutting Depth ◽  
Orthogonal Machining ◽  
Cutting Force Components ◽  
Force Components

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.

scholarly journals Chip Morphology and Delamination Characterization for Vibration-Assisted Drilling of Carbon Fiber-Reinforced Polymer

2019 ◽  
Vol 3 (1) ◽  
pp. 23 ◽  
Author(s):  
Ramy Hussein ◽  
Ahmad Sadek ◽  
Mohamed Elbestawi ◽  
M. Attia
Keyword(s):  
Carbon Fiber ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Chip Morphology ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Polymers ◽  
Geometrical Accuracy ◽  
Carbon Fiber Reinforced

Carbon fiber-reinforced polymers (CFRP) are widely used in the aerospace industry. A new generation of aircraft is being built using CFRP for up to 50% of their total weight, to achieve higher performance. Exit delamination and surface integrity are significant challenges reported during conventional drilling. Exit delamination influences the mechanical properties of machined parts and, consequently, reduces fatigue life. Vibration-assisted drilling (VAD) has much potential to overcome these challenges. This study is aimed at investigating exit delamination and geometrical accuracy during VAD at both low- and high-frequency ranges. The kinematics of VAD are used to investigate the relationship between the input parameters (cutting speed, feed, vibration frequency, and amplitude) and the uncut chip thickness. Exit delamination and geometrical accuracy are then evaluated in terms of mechanical and thermal load. The results show a 31% reduction in cutting temperature, as well as a significant enhancement in exit delamination, by using the VAD technology.

Investigation of the Dynamics of Microend Milling—Part I: Model Development

2006 ◽  
Vol 128 (4) ◽  
pp. 893-900 ◽  
Author(s):  
Martin B. G. Jun ◽  
Xinyu Liu ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor
Keyword(s):  
Cutting Force ◽  
Chip Formation ◽  
Model Development ◽  
Chip Thickness ◽  
Fault System ◽  
Formation Mechanisms ◽  
Force Model ◽  
Line Field ◽  
Fault Parameters ◽  
Microend Milling

In microend milling, due to the comparable size of the edge radius to chip thickness, chip formation mechanisms are different. Also, the design of microend mills with features of a large shank, taper, and reduced diameter at the cutting edges introduces additional dynamics and faults or errors at the cutting edges. A dynamic microend milling cutting force and vibration model has been developed to investigate the microend milling dynamics caused by the unique mechanisms of chip formation as well as the unique microend mill design and its associated fault system. The chip thickness model has been developed considering the elastic-plastic nature in the ploughing process. A slip-line field modeling approach is taken for a cutting force model development that accounts for variations in the effective rake angle and dead metal cap. The process fault parameters associated with microend mills have been defined and their effects on chip load have been derived. Finally, a dynamic model has been developed considering the effects of both the unique microend mill design and fault system and factors that become significant at high spindle speeds including rotary inertia and gyroscopic moments.

scholarly journals Cutting force sensor based on digital image correlation for segmented chip formation analysis

2016 ◽  
Vol 238 ◽  
pp. 466-473 ◽  
Author(s):  
Thomas Baizeau ◽  
Sébastien Campocasso ◽  
Frédéric Rossi ◽  
Gérard Poulachon ◽  
François Hild
Keyword(s):  
Digital Image Correlation ◽  
Cutting Force ◽  
Digital Image ◽  
Chip Formation ◽  
Force Sensor ◽  
Image Correlation ◽  
Segmented Chip

Effect of tool wear on chip formation during dry machining of Ti-6Al-4V alloy, part 1: Effect of gradual tool wear evolution

2015 ◽  
Vol 231 (9) ◽  
pp. 1559-1574 ◽  
Author(s):  
Shoujin Sun ◽  
Milan Brandt ◽  
Matthew S Dargusch
Keyword(s):  
Plastic Deformation ◽  
Tool Wear ◽  
Chip Formation ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Machined Surface ◽  
Segmented Chip ◽  
Gradual Development ◽  
Geometric Variables ◽  
On Chip

Geometric features of the segmented chip have been investigated along with the volume of material removed at a cutting speed at which tool wear is characterized by the gradual development of flank wear when cutting Ti-6Al-4V alloy. The chip geometric variables varied with an increase in the volume of material removed as the combined effect of change in tool’s geometry and increase in cutting temperature. Plastic deformation dimples were observed as periodical regions on the machined surface, a row on each undeformed surface and region on the top of the slipping surface of the segmented chip when cutting with new tool; these dimples on the undeformed surface and machined surface are elongated in the direction of chip flow. All these dimples became less with an increase in the volume of material removed and almost disappeared when the chip was removed with the worn tool at the end of its life. A model of segmented chip formation process has been proposed to satisfactorily explain the formation of the plastic deformation dimples on the undeformed surface and machined surface of the segmented chip produced with a new cutting tool and the transition of chip geometry with the evolution of tool wear.

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.

scholarly journals Experimental Parametric Relationships for Chip Geometry in Dry Machining of the Ti6Al4V Alloy

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1260 ◽  
Author(s):  
Yezika Sánchez Hernández ◽  
Francisco Trujillo Vilches ◽  
Carolina Bermudo Gamboa ◽  
Lorenzo Sevilla Hurtado
Keyword(s):  
Experimental Data ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Cutting Parameters ◽  
Ti6al4v Alloy ◽  
Geometric Parameters ◽  
Dry Machining ◽  
Wide Range ◽  
Parametric Relationships ◽  
Chip Geometry

The Ti6Al4V alloy is included in the group of difficult-to-cut materials. Segmented chips are generated for a wide range of cutting parameters. This kind of chip geometry leads to the periodic variation of machining forces, tool vibrations, and work part-tolerance inaccuracies. Therefore, the analysis of chip morphology and geometry becomes a fundamental machinability criterion. However, few studies propose experimental parametric relationships that allow predicting chip-geometry evolution as a function of cutting parameters. In this work, an experimental analysis of the influence of cutting speed and feed rate on various chip-geometric parameters in dry machining of the Ti6Al4V alloy was carried out. In addition, the chip morphology and chip microstructure were studied. A clear dependence of certain chip-geometric parameters on the cutting parameters studied was found. From the experimental data, several parametric relationships were developed. These relationships were able to predict the evolution of different geometric parameters as a function of cutting speed and feed, within the tested range of values. The differences between the proposed models and the experimental data were also highlighted. These parametric equations allowed quantifying the value of parameters in which the trend was clear.

Sign in / Sign up

Export Citation Format

Share Document