Analysis of Reversible Fine Machining Sequence Effect on Surface Integrity

2006 ◽  
Vol 315-316 ◽  
pp. 391-395
Author(s):  
Wen Ge Wu ◽  
Si Qin Pang ◽  
Zhan Qiang Liu
Keyword(s):  
Surface Roughness ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Machining Process ◽  
Processing Route ◽  
Machining Accuracy ◽  
Machining Efficiency ◽  
Micro Hardness ◽  
Rough Machining ◽  
Machined Surface

Reversible cutting method is a new research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. The aim of the presented work was to analysis the effects of reversible fine machining sequence on surface integrity in machined layer. Nonlinear hardening during reverse loading and the change of the Bauschinger effect factor with plastic strain were properly taken into account. In experiments, the residual stresses have been measured using the X-ray diffraction technique (at the surface of the workpiece and in depth). Moreover, micro-hardness and surface roughness of machined surface are presented. Experimental data for the range of cutting parameters tested showed that the reversible fine machining produce the tensile residual stresses at the surface, which are critical in the performance of the machined components. The experimental results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining show that decreased plastic deformation of the surface layer and work-hardening. Surface roughness of machined surface with reversible finishing is discussed. Research results indicted that it can be adopted such planning which rough machining during advance stroke and fine machining or semi-finishing during return stroke in machining process. In this way, it has such advantages that increase machining efficiency and machining accuracy, decrease bending deformation.

Evaluation of Surface Integrity in Electrochemical Micromachining of A286 Super alloy

2021 ◽  
Author(s):  
Rajkeerthi E ◽  
Hariharan P
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Integrity ◽  
Research Work ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Dissolution Mechanism ◽  
Machined Surface ◽  
Micro Holes ◽  
Super Alloy

Abstract Surface integrity of micro components is a major concern particularly in manufacturing industries as most geometry of the products must meet out necessary surface quality requirements. Advanced machining process like electrochemical micro machining possess the capabilities to machine micro parts with best surface properties exempting them from secondary operations. In this research work, different electrolytes have been employed for producing micro holes in A286 super alloy material to achieve the best surface quality and the measurement of surface roughness and surface integrity to evaluate the machined surface is carried out. The machined micro hole provides detailed information on the geometrical features. A study of parametric analysis meant for controlling surface roughness and improvement of surface integrity has been made to find out the suitable parameters for machining. The suitability of various electrolytes with their dissolution mechanism and the influence of various electrolytes have been thoroughly studied. Among the utilized electrolytes, EG + NaNO3 electrolyte provided the best results in terms of overcut and average surface roughness.

Research and Application on High Efficiency Reversible Cutting Technique

2004 ◽  
Vol 471-472 ◽  
pp. 825-829
Author(s):  
Wen Ge Wu ◽  
Si Qin Pang ◽  
Qi Xun Yu
Keyword(s):  
High Efficiency ◽  
Cutting Tool ◽  
Handling Time ◽  
Cutting Parameters ◽  
Machining Process ◽  
Processing Route ◽  
Rough Machining ◽  
Machined Surface ◽  
Primary Motion ◽  
The Way

Reversible cutting method is a research thesis proposed to shorten processing route, decrease tool number and handling time, increase machining efficiency. There are three movement ways, i.e. reversible feed motion, reversible primary motion and reversible composite motion. Primary motion is done by workpiece, conventional or reversible feed motion is done by cutting tool in the way of reversible feed motion, e.g. turning. Cutting velocity is passed to cutting tool, clockwise or anti-clockwise cutting movement is done by cutting tool in the way of reversible primary motion, e.g. milling, shaping, drilling (spade drill), reaming. Primary and feed motions are all reversible in composite motion, e.g. turn-milling. Chip deformation and machined surface with reversible finishing is discussed. A mechanical analysis is carried out to the workpiece deformation of slender shaft turning in normal direction and reversible direction. The result has been verified by experiments. Experimental data for the range of cutting parameters tested showed that the reversible fine machining produce the compressive residual stresses at the surface, which are critical in the performance of the machined components. Experimental research indicted that the results of micro-hardness of reversible fine machining technique are smaller than that of general fine machining show that decreased plastic deformation of the surface layer and work-hardening. It can be adopted such planning which rough machining during advance stroke and fine machining during return stroke in machining process.

scholarly journals Surface Analysis of Wire-Electrical-Discharge-Machining-Processed Shape-Memory Alloys

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 530 ◽  
Author(s):  
Rakesh Chaudhari ◽  
Jay J. Vora ◽  
Vivek Patel ◽  
L. N. López de Lacalle ◽  
D. M. Parikh
Keyword(s):  
Surface Roughness ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Surface Integrity ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Wire Electrical Discharge Machining ◽  
Machined Surface ◽  
Edx Analysis

Shape-memory alloys such as nitinol are gaining popularity as advanced materials in the aerospace, medical, and automobile sectors. However, nitinol is a difficult-to-cut material because of its versatile specific properties such as the shape-memory effect, superelasticity, high specific strength, high wear and corrosion resistance, and severe strain hardening. Anunconventional machining process like wire-electrical-discharge-machining (WEDM) can be effectively and efficiently used for the machining of such alloys, although the WEDM-induced surface integrity of nitinol hassignificant impact on material performance. Therefore, this work investigated the surface integrity of WEDM-processed nitinol samples using digital microscopy imaging, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. Three-dimensional analysis of the surfaces was carried out in two different patterns (along the periphery and the vertical plane of the machined surface) andrevealed that surface roughness was maximalat the point where the surface was largely exposed to the WEDM dielectric fluid. To attain the desired surface roughness, appropriate discharge energy is required that, in turn, requires the appropriate parameter settings of the WEDM process. Different SEM image analyses showed a reduction in microcracks and pores, and in globule-density size at optimized parameters. EDX analysis revealed the absence of wire material on the machined surface

Evaluation of Surface Integrity during Machining with Different Tool Grades of Sicp/Al-Si Composites Produced by Powder Metallurgy

2011 ◽  
Vol 672 ◽  
pp. 319-322 ◽  
Author(s):  
Mustafa Günay ◽  
Ulvi Şeker
Keyword(s):  
Surface Roughness ◽  
Powder Metallurgy ◽  
Surface Integrity ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Machining Process ◽  
Machined Surface ◽  
Alloy Matrix ◽  
Surface Finishes

MMCs components are mostly produced using near net shape manufacturing methods and are subsequently machined to the final dimensions and surface finishes. The MMCs consist of extremely hard reinforcing particles and pose considerable challenges due to the poor machinability and severe wear of the cutting tool. In this study, cutting performance of WC, CBN and PCD cutting tools were investigated with respect to surface roughness during machining of 10 wt % SiCp reinforced Al-Si alloy matrix composites produced by powder metallurgy (PM) method. Average surface roughness (Ra) corresponding to each machining condition was measured. After the machining process the worn insert tips were examined under the scanning electron microscope (SEM). Chip geometry and machined surface photographs have been taken by optical microscopy. The experimental results showed that surface roughness decreased with increasing cutting speed for all of cutting tool materials. The best surface integrity was occurred after the machining with PCD insert at the highest cutting speed employed.

Influence of Tool Flank Wear on Surface Integrity in Orthogonal Milling of Powder Metallurgy Superalloy

2012 ◽  
Vol 723 ◽  
pp. 182-187
Author(s):  
Jin Du ◽  
Zhan Qiang Liu
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Flank Wear ◽  
White Layer ◽  
Micro Hardness ◽  
Machined Surface ◽  
Tool Flank Wear ◽  
White Layer Thickness ◽  
Cemented Carbide Tools ◽  
Coated Cemented Carbide

Tool flank wear has the significant effects on machined surface integrity. The influences of tool flank wear on the cutting forces, surface roughness, microhardness and white layer thickness are investigated in this paper through orthogonal milling experiments. FGH95 powder metallurgy (PM) superalloys are machined with coated cemented carbide tools in the milling experiments. The experiment results show that with the increasing of tool flank wear, cutting force, surface roughness and white layer thickness increase. However, the machined surfaces micro-hardness aggravates with the increase of tool flank wear. It is found that, the machined surface roughness, micro-hardness and white layer increase dramatically especially when the tool flank wear exceeds 0.3mm. A conclusion is then be drawn that, the maximum acceptable tool flank wear land is 0.3mm from the view point of surface integrity when FGH95 PM superalloy is machined with coated cemented carbide tools.

Investigation of the Impact of Cutting Parameters on Surface Integrity in the End Milling of Inconel 625

2019 ◽  
Vol 969 ◽  
pp. 762-767 ◽  
Author(s):  
Ramesh Rajguru ◽  
Hari Vasudevan
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Inconel 625 ◽  
Micro Hardness ◽  
Machined Surface ◽  
Radial Rake Angle ◽  
Radial Depth ◽  
The Impact

Nickel based super alloys, such as Inconel 625 is amongst the most difficult to machine, due to its low thermal conductivity and high strength at higher temperature. Although, they are used in aerospace exhaust systems and other applications, the strain hardening that results during the machining operation, which adversely affects surface integrity of machined surface of such materials especially in extensive applications, is a cause for concern. In this context, this study was carried out, involving the milling operation, using solid carbide tools coated with TiAlSiN, under specifically developed conditions for dry machining of the difficult to cut materials. The cutting parameters were 4 in number, namely radial rake angle, feed per tooth, cutting speed and radial depth of cut and the response parameters included surface integrity characteristics, such as residual stresses, surface roughness and micro-hardness. Based on the experimental analyses, it was found that the micro-hardness of machined surface was higher. Micro hardness of sub surface decreases with the depth (50,100,150,250μm) due to a reduction in the work hardening of the Inconel 625, underneath the surface layer. The residual stresses were analyzed using main effect plot, and it was seen that the residual stresses were significantly influenced by the radial rake angle, followed by feed per tooth.

Some Aspects of Improving Integrity of Machined Surfaces on Al/SiCp Metal Matrix Composites

2010 ◽  
Vol 443 ◽  
pp. 596-601 ◽  
Author(s):  
Uday A. Dabade ◽  
Suhas S. Joshi
Keyword(s):  
Surface Roughness ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Experimental Work ◽  
Metal Matrix ◽  
Cutting Tool ◽  
Matrix Composites ◽  
Machined Surface ◽  
Machined Surface Roughness ◽  
Machined Surfaces

This paper presents findings of an experimental work which involved use of wiping edge on the cutting tool and a priory heating of the work surfaces to improve the integrity of machined surfaces. The wiper edge cleans the machined surface and a priory heating induces necessary local ductility into the machined surface to promote improvement in the surface integrity. The result shows that the wiper inserts reduce surface roughness (by about 38%); cutting forces (by about 8%) and induce compressive (or lower tensile) residual stresses in the machined surfaces, hence help to improve the surface integrity. Similarly, a priory heating of work surfaces at 70°C was also found to improve machined surface roughness considerably.

Analysis of Residual Stresses in Sustainable Cryogenic Machining of Nickel Based Alloy—Inconel 718

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Jani Kenda ◽  
Franci Pusavec ◽  
Janez Kopac
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Inconel 718 ◽  
Machining Process ◽  
Cryogenic Machining ◽  
Machining Processes ◽  
Machined Surface ◽  
Nickel Based Alloy ◽  
And Performance ◽  
Conventional Machining

In machining processes, surface integrity is a major quality-related performance output. In the case of difficult-to-cut materials, this frequently relates to residual stresses induced in the machined surface and subsurface. As cryogenic machining presents a sustainable alternative to conventional machining processes, in this work, cryogenic machining and the influence of cooling/lubrication conditions on the surface integrity generated during turning of Inconel 718 are presented. The results show that the cryogenic machining process generates larger compressive residual stresses, and prevail at deeper levels beneath the machined surface, thus resulting in improved product quality and performance characteristics in terms of fatigue life and wear resistance.

scholarly journals Influence of turning tool wear on the surface integrity and anti-fatigue behavior of Ti1023

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Li Xun ◽  
Wang Ziming ◽  
Yang Shenliang ◽  
Guo Zhiyuan ◽  
Zhou Yongxin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Tool Wear ◽  
Surface Integrity ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Machined Surface ◽  
Deformation Layer

Titanium alloy Ti1023 is a typical difficult-to-cut material. Tool wear is easy to occur in machining Ti1023, which has a significant negative effect on surface integrity. Turning is one of the common methods to machine Ti1023 parts and machined surface integrity has a direct influence on the fatigue life of parts. To control surface integrity and improve anti-fatigue behavior of Ti1023 parts, it has an important significance to study the influence of tool wear on the surface integrity and fatigue life of Ti1023 in turning. Therefore, the effect of tool wear on the surface roughness, microhardness, residual stress, and plastic deformation layer of Ti1023 workpieces by turning and low-cycle fatigue tests were studied. Meanwhile, the influence mechanism of surface integrity on anti-fatigue behavior also was analyzed. The experimental results show that the change of surface roughness caused by worn tools has the most influence on anti-fatigue behavior when the tool wear VB is from 0.05 to 0.25 mm. On the other hand, the plastic deformation layer on the machined surface could properly improve the anti-fatigue behavior of specimens that were proved in the experiments. However, the higher surface roughness and significant surface defects on surface machined utilizing the worn tool with VB = 0.30 mm, which leads the anti-fatigue behavior of specimens to decrease sharply. Therefore, to ensure the anti-fatigue behavior of parts, the value of turning tool wear VB must be rigorously controlled under 0.30 mm during finishing machining of titanium alloy Ti1023.

Surface integrity of quenched steel 1045 machined by CBN grinding wheel and SiC grinding wheel

2017 ◽  
Vol 8 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Kankan Ji ◽  
Xingquan Zhang ◽  
Shubao Yang ◽  
Liping Shi ◽  
Shiyi Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Compressive Stress ◽  
Surface Integrity ◽  
Grinding Wheel ◽  
Micro Hardness ◽  
Content Type ◽  
Quenched Steel ◽  
Cut Depth ◽  
Cbn Grinding Wheel

Purpose The purpose of this paper is to evaluate surface integrity of quenched steel 1045 ground drily by the brazed cubic boron nitride (CBN) grinding wheel and the black SiC wheel, respectively. Surface integrity, including surface roughness, sub-surface hardness, residual stresses and surface morphology, was investigated in detail, and the surface quality of samples ground by two grinding wheels was compared. Design/methodology/approach In the present work, surface integrity of quenched steel 1045 machined by the CBN grinding wheel and the SiC wheel was investigated systematically. All the specimens were machined with a single pass in the down-cutting mode of dry condition. Surface morphology of the ground specimen was observed by using OLYMPUS BX51M optical microscopy. Surface roughness of seven points was measured by using a surface roughness tester at a cut-off length of 1.8 mm and the measurement traces were perpendicular to the grinding direction. Sub-surface micro-hardness was measured by using HVS-1000 digital micro-hardness tester after the cross-section surface was polished. The residual stress was tested by using X-350A X-ray stress analyzer. Findings When the cut depth is increased from 0.01 to 0.07 mm, the steel surface machined by the CBN wheel remains clear grinding mark, lower roughness, higher micro-hardness and higher magnitude of compressive stress and fine microstructure, while the surface machined by the SiC grinding wheel becomes worse with increasing of cut depth. The value of micro-hardness decreases, and the surface roughness increases, and the surface compressive stress turns into tensile stress. Some micro-cracks and voids occur when the sample is processed by the SiC grinding wheel with cut depth 0.07 mm. Originality/value In this paper, the specimens of quenched steel 1045 were machined by the CBN grinding wheel and the SiC wheel with various cutting depths. The processing quality resulted from the CBN grinding wheel is better than that resulted from the SiC grinding wheel.

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