Influence of Milling on Surface Integrity of Ti-6Al-4V

2013 ◽  
Vol 698 ◽  
pp. 127-136 ◽  
Author(s):  
Kamel Moussaoui ◽  
Michel Mousseigne ◽  
Johanna Senatore ◽  
Pierre Lagarrigue ◽  
Yves Caumel
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Cutting Speed ◽  
Orange Peel ◽  
Influential Factor ◽  
Nose Radius ◽  
Machined Surface ◽  
Naked Eye ◽  
Deformed Layer ◽  
Softened Zone

The present article addresses the influence of milling on the surface integrity of Ti-6Al-4V. Observation of the machined surface from a macroscopic perspective (naked eye) has highlighted anorange peelphenomenon. Under the machined surface no plastically deformed layer or lengthening of the grains were observed. As far as microhardness is concerned, a slightly softened zone was noted under the machined surface. Diffusion of vanadium from phase β to phase α also occurred but without resulting change to the microstructure. Measurement of microhardness and residual stresses showed that the finishing pass predominated over the roughing pass in terms of its influence on surface integrity. The response surface methodology was used in order to highlight those parameters influencing surface integrity. Its application and processing showed that the most influential factor is the nose radius for roughness and the cutting speed for residual stresses.

The influence of turning parameters on surface integrity of nickel alloy 625

2016 ◽  
Vol 232 (10) ◽  
pp. 1837-1847 ◽  
Author(s):  
Daniel Loureiro ◽  
Anselmo E Diniz ◽  
Alexandre B Farina ◽  
Sérgio Delijaicov
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Cold Work ◽  
Cutting Speed ◽  
Tool Geometry ◽  
Machined Surface ◽  
Alloy 625 ◽  
Industrial Sectors ◽  
Coated Carbide ◽  
Compressive Residual Stresses

Nickel-based alloys are used in industrial sectors where high mechanical strength and corrosion resistance are required at high temperatures. However, these alloys have low machinability as a consequence of inherent properties. Some of these properties such as high cold work hardening rate and low heat conductivity may cause damages to the machined surface. Among the nickel-based alloys, one that has good properties for oil exploration is alloy 625. As the components made of this alloy are frequently used in very rough environments, this study sought to evaluate the influence of tool geometry, cutting conditions (feed and cutting speed) and tool condition (fresh or worn) on the surface integrity of turned alloy 625 parts in order to discover turning practices for this alloy that result in minimal damage to the workpiece surface. A secondary aim was to evaluate how these input variables affected the life of the coated carbide tools used in the turning experiments with this alloy. The main conclusions are that (a) the surfaces produced with a fresh tool with positive geometry had compressive residual stresses, while those produced with negative tool geometry had tensile residual stresses and (b) when a worn tool was used all the surfaces produced had compressive residual stresses.

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.

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.

Influence of Cutting Speed on Surface Plastic Deformation and White Layer Formation of FGH95

2013 ◽  
Vol 589-590 ◽  
pp. 70-75 ◽  
Author(s):  
Jin Du ◽  
Zhan Qiang Liu
Keyword(s):  
Plastic Deformation ◽  
Surface Integrity ◽  
White Layer ◽  
High Reliability ◽  
Cutting Speed ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Layer Formation ◽  
Machined Surface ◽  
White Layer Formation

The superalloy parts in the aeronautical field demand high reliability, which is largely related to surface integrity. Surface integrity generally includes three parameters, such as geometric parameter, mechanical parameter and metallurgical parameter. The paper presents the influence of cutting speed on surface plastic deformation and white layer formation through orthogonal milling of FGH95 superally material. The influence of cutting speed on grain refinement of machined surface is also investigated. It is found that cutting speed has significantly effect on the surface metallurgical characteristic microstructure. The increasing of cutting speed creates severer plastic deformation. Surface plastic shear strain increases with the increasing of cutting speed, while the depth of plastic deformation decreases on contrary. White layer thickness is increased with the increasing of cutting speed. Through statistical analysis for grains number, it can be drawn that the higher the cutting speed, the more serious grains refinement.

Considerations Regarding Some Surface State Parameters Characterized by a more Restricted Use

2015 ◽  
Vol 809-810 ◽  
pp. 93-98
Author(s):  
Ionuţ Urzică ◽  
Ciprian Râznic ◽  
Mihai Apostol ◽  
Corina Mihaela Pavăl ◽  
Mihai Boca ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Roughness Parameter ◽  
Cutting Speed ◽  
Roughness Parameters ◽  
Turning Process ◽  
Nose Radius ◽  
Machined Surface ◽  
Surface Roughness Parameter ◽  
Surface Roughness Parameters ◽  
Restricted Use

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use

Effect of Machining Parameters and MQL Liquids on Surface Integrity of High Speed Drilling Ti-6Al-4V

2010 ◽  
Vol 447-448 ◽  
pp. 816-820 ◽  
Author(s):  
Erween Abdul Rahim ◽  
Hiroyuki Sasahara
Keyword(s):  
Surface Roughness ◽  
Palm Oil ◽  
Surface Integrity ◽  
High Speed ◽  
Cutting Speed ◽  
Machining Parameters ◽  
Machined Surface ◽  
Subsurface Deformation ◽  
High Speed Drilling ◽  
Coated Carbide

Surface integrity is particularly important for the aerospace industry components in order to permit longer service life and maximized its reliability. This present work compares the performance of palm oil and synthetic ester on surface roughness, surface defect, microhardness and subsurface deformation when high speed drilling of Ti-6Al-4V under MQL condition. The drilling tests were conducted with AlTiN coated carbide tool. The surface roughness decreased with increasing in cutting speed and thicker subsurface deformation was formed underneath the machined surface. Grooves, cavities, pit holes, microcracks and material smearing were the dominant surface damages thus deteriorated the machined surface. For both lubricants, the machined surface experienced from thermal softening and work hardening effect thus gave a variation in microhardness values. The results indicated the substantial benefit of MQL by palm oil on surface integrity.

RSM Based Investigations on the Effects of Cutting Parameters on Surface Integrity during Cryogenic Hard Turning of AISI 52100

2015 ◽  
Vol 15 (3) ◽  
pp. 309-318 ◽  
Author(s):  
Suha K. Shihab ◽  
Zahid A. Khan ◽  
Arshad Noor Siddiquee
Keyword(s):  
Surface Integrity ◽  
Feed Rate ◽  
Hard Turning ◽  
Desirability Function ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Aisi 52100 ◽  
Model Equations

AbstractEffect of cryogenic hard turning parameters (cutting speed, feed rate, and depth of cut) on surface roughness (Ra) and micro-hardness (µH) that constitute surface integrity (SI) of the machined surface of alloy steel AISI 52100 is investigated. Multilayer hard surface coated (TiN/TiCN/Al2O3/TiN) insert on CNC lathe is used for turning under different cutting parameters settings. RSM based Central composite design (CCD) of experiment is used to collect data for Ra and µH. Validity of assumptions related to the collected data is checked through several diagnostic tests. The analysis of variance (ANOVA) is used to determine main and interaction effects. Relationship between the variables is established using quadratic regression model. Both Ra and µH are influenced principally by the cutting speed and the feed rate. Model equations are found to predict accurate values of Ra and µH. Finally, desirability function approach for multiple response optimization is used to produce optimum SI.

A Study of Surface Integrity when Machining Refractory Titanium Alloys

2009 ◽  
Vol 83-86 ◽  
pp. 1059-1068 ◽  
Author(s):  
Armansyah Ginting ◽  
Mohammed Nouari ◽  
Nadhir Lebaal
Keyword(s):  
Surface Roughness ◽  
Titanium Alloys ◽  
Surface Integrity ◽  
Bulk Material ◽  
Cutting Speed ◽  
Cutting Condition ◽  
Feed Speed ◽  
Machined Surface ◽  
Feed Mark ◽  
Coated Carbide

In this paper, the surface integrity is studied when machining the aeronautical titanium alloys. Surface roughness, lay, defects, microhardness and microstructure alterations are studied. The result of surface roughness judges that the CVD-coated carbide fails to produce better Ra value than the uncoated. Lay is characterized by cutting speed and feed speed directions. Feed mark, tearing surface, chip layer formation as built up layer (BUL), and deposited microchip are the defects. Microhardness is altered down to 350 microns beneath the machined surface. The first 50 microns is the soft sub-surface caused by thermal softening in ageing process. Microstructure alteration is observed in this sub-surface. Down to 200 microns is the hard sub-surface caused by the cyclic internal work hardening and then it is gradually decreasing to the bulk material hardness. It is concluded that dry machining titanium alloy is possible using uncoated carbide with cutting condition limited to finish or semi-finish for minimizing surface integrity alteration.

Surface Integrity of Die Material in High Speed Hard Machining, Part 1: Micrographical Analysis

1999 ◽  
Vol 122 (4) ◽  
pp. 620-631 ◽  
Author(s):  
T. I. El-Wardany ◽  
H. A. Kishawy ◽  
M. A. Elbestawi
Keyword(s):  
Tool Wear ◽  
Residual Stresses ◽  
Tool Steel ◽  
Surface Integrity ◽  
High Speed ◽  
Cutting Conditions ◽  
Metallographic Analysis ◽  
Tool Geometry ◽  
Machined Surface ◽  
Geometrical Defects

The effects of cutting conditions and tool wear on chip morphology and surface integrity during high speed machining of D2 tool steel (60–62 Hrc) are investigated experimentally and analytically in this paper. Polycrystalline Cubic Boron Nitride (PCBN) tools are used in this investigation. The chips and the subsurface of the workpiece are examined using optical and scanning electron microscopy. Microhardness measurements are performed on the surface and subsurface of the workpiece. The X-ray diffraction technique is used to measure the residual stresses induced in the machined surface. The paper is divided into two parts. Part 1 presents the results obtained from the micrographical analysis of the chips and the surfaces produced. Part 2 deals with microhardness and residual stresses of the machined surface. The micrographical analysis of the chips produced shows that different mechanisms of chip formation exist depending on the magnitude of the cutting pressure and tool wear. Saw toothed chips are produced during the machining of D2 tool steel if the cutting pressure exceeds approximately 4000 MPa. The metallographic analysis of the surface produced illustrates the damaged surface region that contains geometrical defects and changes in the subsurface metallurgical structure. The types of surface damage are dependent on the cutting conditions, tool geometry and the magnitude of the wear lands. [S1087-1357(00)00104-0]

Non-Destructive Inspection of Surface Integrity in Milled Turbine Blades of Inconel 738LC

2013 ◽  
Vol 486 ◽  
pp. 9-15 ◽  
Author(s):  
Kamil Kolařík ◽  
Zdenek Pala ◽  
Libor Beranek ◽  
Jiří Čapek ◽  
Zdenek Vyskocil ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Turbine Blades ◽  
Mutual Effect ◽  
Work Piece ◽  
Machined Surface ◽  
Grain Sizes ◽  
Cutter Orientation ◽  
Inconel 738Lc ◽  
Non Destructive

Nickel super-alloys are widely used in aerospace as material for turbine blades. Unfortunately, their machining is difficult since mechanical hardening and, consequently, extreme tool wear occur. Casting can no longer meet the requirements for precision, hence, the castings are being ground or milled. In this contribution, a quality check of the milled surface by several surface integrity parameters is proposed with respect to the surface structural inhomogeneities caused by mutual effect of plastic deformations and thermal fields during the cutting process. Castings from Inconel 738LC were milled with cutting conditions chosen by Design-Of-Experiments method and the resulting surfaces were assessed by non-destructive X-ray diffraction methods in several areas corresponding to various cutter orientation and work-piece angle. Surface integrity was described by macroscopic residual stresses, microstrains, grain sizes and phase composition. Mostly, favourable compressive surface residual stresses were observed in the cutting direction, grain sizes were distinctively smaller when the tool axis was perpendicular to the machined surface.

Sign in / Sign up

Export Citation Format

Share Document