scholarly journals Study on Cutting Form and Surface Machining Quality of Wheel Tread under Reprofiling

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jianxi Wang ◽  
Xin Xue ◽  
Yongjie Lu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Element Model ◽  
Maintenance Cost ◽  
Serrated Chip ◽  
Machined Surface ◽  
Surface Machining ◽  
Machining Quality

The wheelset maintenance cost is an important part of train maintenance cost. Researchers and railway operators have been closely concerned about the way to minimize residual stress at wheel tread and surface roughness during wheel reprofiling, thereby reducing the wheel damage during operation, extending the wheelset service life, and cutting down wheelset maintenance cost. The present study involves dynamic simulation of tread reprofiling process by building a finite element model of wheel reprofiling, taking the wheel steel as research object. This paper makes a comprehensive analysis of surface roughness and residual stress distribution of wheel tread under different milling parameters. The simulation results indicate that the increase in cutting speed and back cutting depth causes the chip morphology to change while impairing the machined surface quality. Once serrated chip occurs, it means wheel tread machining quality deteriorates remarkably. In this way, the paper associates macroscopic chip morphology with microcosmic surface roughness and internal residual stress to provide theoretical basis for optimization of wheel reprofiling process.

Investigation of Surface Characteristics and Chip Morphology in High Speed Cutting of Inconel718 Based on SHPB System

2019 ◽  
Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Surface Profile ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Machined Surface ◽  
High Speed Cutting

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.

Surface Integrity and Fatigue Property of a High Speed Milled Titanium Alloy

2008 ◽  
Vol 53-54 ◽  
pp. 305-310 ◽  
Author(s):  
Guo Sheng Geng ◽  
Jiu Hua Xu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Surface Integrity ◽  
Work Hardening ◽  
High Speed ◽  
Cutting Speed ◽  
Fatigue Property ◽  
Machined Surface ◽  
Metallurgical Structure

Surface integrity has a great effect on the fatigue property of titanium alloy. The surface integrity and fatigue property of a high speed milled Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy were investigated in this research. The main objective of this paper is to study the influence of milling speed on the surface integraty and fatigue property of the machined part. The surface roughness, work hardening, metallurgical structure and residual stress of the machined surface were studied in a cutting speed range of from 50m/min to 300m/min. To verify the relationship between cutting speed and the surface integrity of machined surface, the fatigue property of titanium alloy specimens milled at four different cutting speeds ranging from 50 to 200m/min were compared at two stress levels. This research shows that the cutting speed has little effect on the work hardening, metallurgical structure and residual stress, but the surface roughness decreases with the increasing cutting speed. Therefore, increasing milling speed has a positive effect on the surface integrity and fatigue property of the machined surface.

scholarly journals Study on the Formation Mechanism of Surface Adhered Damage in Ball-End Milling Ti6Al4V

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7143
Author(s):  
Anshan Zhang ◽  
Caixu Yue ◽  
Xianli Liu ◽  
Steven Y. Liang
Keyword(s):  
Formation Mechanism ◽  
Complex Geometry ◽  
End Milling ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Milling Process ◽  
Cutting Edge ◽  
Machined Surface ◽  
Surface Machining ◽  
Feed Direction

Ball-end cutters are widely used for machining the parts of Ti-6Al-4V, which have the problem of poor machined surface quality due to the low cutting speed near the tool tip. In this paper, through the experiments of inclined surface machining in different feed directions, it is found that the surface adhered damages will form on the machined surface under certain tool postures. It is determined that the formation of surface adhered damage is related to the material adhesion near the cutting edge and the cutting-into/out position within the tool per-rotation cycle. In order to analyze the cutting-into/out process more clearly under different tool postures, the projection models of the cutting edge and the cutter workpiece engagement on the contact plane are established; thus, the complex geometry problem of space is transformed into that of plane. Combined with the case of cutting-into/out, chip morphology, and surface morphology, the formation mechanism of surface adhered damage is analyzed. The analysis results show that the adhered damage can increase the height parameters Sku, Sz, Sp, and Sv of surface topographies. Sz, Sp, and Sv of the normal machined surface without damage (Sku ≈ 3) are about 4–6, 2–3, and 2–3 μm, while Sz, Sp, and Sv with adhered damage (Sku > 3) can reach about 8–20, 4–14, and 3–6 μm in down-milling and 10–25, 7–18, and 3–7 μm in up-milling. The feed direction should be selected along the upper left (Q2: β∈[0°, 90°]) or lower left (Q3: β∈[90°, 180°]) to avoid surface adhered damage in the down-milling process. For up-milling, the feed direction should be selected along the upper right (Q1: β∈(−90°, 0°]) or upper left (Q2: β∈[0°, 90°)).

scholarly journals On the Effect of Electron Beam Melted Ti6Al4V Part Orientations during Milling

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1172
Author(s):  
Abdulmajeed Dabwan ◽  
Saqib Anwar ◽  
Ali M. Al-Samhan ◽  
Mustafa M. Nasr
Keyword(s):  
Surface Roughness ◽  
Electron Beam ◽  
Surface Morphology ◽  
Surface Quality ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Radial Depth

The machining of the electron beam melting (EBM) produced parts is a challenging task because, upon machining, different part orientations (EBM layers’ orientations) produce different surface quality even when the same machining parameters are employed. In this paper, the EBM fabricated parts are machined in three possible orientations with regard to the tool feed direction, where the three orientations are “tool movement in a layer plane” (TILP), “tool movement perpendicular to layer planes” (TLP), and “tool movement parallel to layers planes” (TPLP). The influence of the feed rate, radial depth of cut, and cutting speed is studied on surface roughness, cutting force, micro-hardness, microstructure, chip morphology, and surface morphology of Ti6Al4V, while considering the EBM part orientations. It was found that different orientations have different effects on the machined surface during milling. The results show that the EBM parts can achieve good surface quality and surface integrity when milled along the TLP orientation. For instance, surface roughness (Sa) can be improved up to 29% when the milling tool is fed along the TLP orientation compared to the other orientations (TILP and TPLP). Furthermore, surface morphology significantly improves with lower micro-pits, redeposited chips, and feed marks in case of the TLP orientation.

scholarly journals The prediction of the turned machining induced residual stresses in Ti6Al4V: A Critical Surface Integrity Descriptor

2021 ◽  
Vol 347 ◽  
pp. 00037
Author(s):  
Gary Styger ◽  
Rudolph F Laubscher
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Cutting Speed ◽  
Element Model ◽  
Rake Angle ◽  
Critical Surface ◽  
Machining Parameters ◽  
Machined Surface ◽  
Wide Range

The surface integrity of a turned machined surface is an essential indicator of the fatigue and corrosion performance of a component. A critical descriptor of this property is the residual stress, both on the surface and subsurface of a part. However, experimental determination of vital surface integrity parameters such as surface roughness, hardness, affected microstructure, and residual stresses is costly, time consuming, and involves the destruction of the part. Therefore, prediction of these parameters, such as residual stress versus depth, would be of great value and could aid in the correct machining parameters (cutting speed, feed rate, edge tool radius, rake angle, coolant) for the desired part performance. A study was initiated to determine the influence of a worn tool and multiple cuts on a wide range of cutting speeds on residual stresses induced by machining an outside-turned bar of Ti6Al4V titanium alloy. Thus, a project was initiated to develop a non-linear finite element model to predict the residual stresses thus developed due to the machining manufacturing process.

Simulation and Experiment on the Residual Stress in Super-High Speed Grinding

2010 ◽  
Vol 135 ◽  
pp. 238-242
Author(s):  
Yue Ming Liu ◽  
Ya Dong Gong ◽  
Wei Ding ◽  
Ting Chao Han
Keyword(s):  
Residual Stress ◽  
High Speed ◽  
Element Model ◽  
Residual Stress Distribution ◽  
X Ray Diffraction ◽  
Machined Surface ◽  
X Ray ◽  
High Speed Grinding ◽  
Simulation And Experiment ◽  
Cylindrical Workpiece

In this paper, effective finite element model have been developed to simulation the plastic deformation cutting in the process for a single particle via the software of ABAQUS, observing the residual stress distribution in the machined surface, the experiment of grinding cylindrical workpiece has been brought in the test of super-high speed grinding, researching the residual stress under the machined surface by the method of X-ray diffraction, which can explore the different stresses from different super-high speed in actual, and help to analyze the means of reducing the residual stresses in theory.

Experimental Investigation on Surface Roughness in Precision Cutting Ti6Al4V Alloy Using Diamond Tools

2014 ◽  
Vol 800-801 ◽  
pp. 576-579
Author(s):  
Lin Hua Hu ◽  
Ming Zhou ◽  
Yu Liang Zhang
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Polycrystalline Diamond ◽  
Cutting Parameters ◽  
Limited Range ◽  
Nose Radius ◽  
Machined Surface ◽  
Machined Surface Roughness ◽  
Titanium Alloy Ti6al4v ◽  
Pcd Tools

In this work, cutting experiments were carried out on titanium alloy Ti6Al4V by using polycrystalline diamond (PCD) tools to investigate the effects of the tool geometries and cutting parameters on machined surface roughness. Experimental results show machined surface roughness decreases with increases in the flank angle, tool nose radius and cutting speed within a limited range respectively, and begins to increase as the factors reaches to certain values respectively. And machined surface roughness decreases with increases in feed rate and cutting depth respectively.

Effect of Surface Machining on the Fatigue Life of Low Alloy Steel for Hydrogen Pressure Vessels

2007 ◽  
Author(s):  
Yoru Wada ◽  
Ryoji Ishigaki ◽  
Yasuhiko Tanaka ◽  
Tadao Iwadate ◽  
Keizo Ohnishi
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
Annealed Specimen ◽  
Surface Machining ◽  
Hydrogen Fatigue ◽  
Effect Of Surface

The effect of surface machining on fatigue life in high pressure hydrogen gas was investigated. The test was conducted under the elastic range under 45MPa gaseous hydrogen environment by the ground specimen which were machined so that the surface roughness to be Rmax = 19μm(Mark: 19s), 26μm(26s) and 93μm(93s) and by the polished specimen which are prepared so that the surface roughness to be Rmax = 1μm(1s), 3.6μm(3.6s) and 10μm(10s). The hydrogen fatigue life of ground specimens was considerably reduced with increasing surface roughness as compared to the fatigue life in air at the same surface condition. On the other hand, for the annealed conditions of the ground specimen, the reduction by hydrogen effect was fairly small. The residual stress for the ground specimen at the surface rises sharply in tension while the residual stress for the annealed specimen was nearly equal to zero. We have shown that the hydrogen fatigue damage can be evaluated by obtaining the information about residual stress on surface, stress concentration by maximum surface roughness and the threshold stress intensity SH above which hydrogen fatigue damage occurs.

scholarly journals Influence of Chatter of VMC Arising During End Milling Operation and Cutting Conditions on Quality of Machined Surface

1970 ◽  
Vol 2 (1) ◽  
Author(s):  
A.K.M.N. Amin, M.A. Rizal, and M. Razman
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Metal Removal ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
End Mill ◽  
Machined Surface ◽  
Operating Cycle ◽  
Wide Range

Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metal cutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC), which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC.  Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed.  It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

Effect of Milling Speed and Feed on Surface Residual Stress of 7050-T7451 Aluminum Alloy

2012 ◽  
Vol 499 ◽  
pp. 217-222 ◽  
Author(s):  
C. Li ◽  
Yi Wan ◽  
R.R. Zhang ◽  
Zhan Qiang Liu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Cutting Speed ◽  
Diffraction Method ◽  
Cutting Condition ◽  
Feed Speed ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
Orthogonal Direction ◽  
Machined Surface

The residual stress in the milling of 7050-T7451 aluminum alloy was measured using X-ray diffraction method in which Psi-oscillation, Phi-oscillation and peak fit were adopted. Cutting speed and feed are main variables which were considered in this study. The results show that compressive residual stresses are generated in surface for the down milling generally, which is mainly due to burnishing effect between the tools flank face and the machined surface. In feed and its orthogonal direction, the effect of cutting speed and feed speed on residual stress is similar. Therefore, required residual stress can be achieved by controlling the cutting condition such as cutting speed, feed speed etc.

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