Minimized Wear and Debris Generation Through Optimized Machining of Co-Cr-Mo Alloys for Use in Metal-on-Metal Hip Implants

2012 ◽  
Author(s):  
Ashish Deshpande ◽  
Shu Yang ◽  
Dave Puleo ◽  
David Pienkowski ◽  
Oscar Dillon ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Wear Debris ◽  
Wear Behavior ◽  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machining Conditions ◽  
Metal On Metal ◽  
Tool Edge

More than 380,000 hips are replaced with total joint prostheses each year in the U.S. Wear debris generated by metal-on-metal implant designs is of concern due to potential adverse biological effects arising from chronic exposure of human tissue to the wear debris. This paper presents a new methodology for optimizing the wear performance of prosthesis made of Co-Cr-Mo alloys by varying tool edge geometry and machining conditions to alter the wear behavior of this alloy, while also controlling the residual stresses induced during the machining process. The machining process causes inhomogeneous inelastic deformations near the surface layer of machined parts which create residual stresses in the surface of machined components. Residual stresses in the machined surface and the subsurface are affected by cutting tool material, tool geometry, workpiece, tool-work interface conditions, and the cutting parameters such as feed rate, depth of cut and cutting speed. In the current work, residual stresses were measured using X-ray diffraction technique (XRD). The surface residual stresses in two directions (radial and hoop) were measured on the machined pins after machining with different machining conditions, but prior to the wear test. Wear behavior of Co-Cr-Mo alloy pin specimens, produced from machining with varying tool edge geometry and machining conditions, was studied using a custom-made biaxial motion pin-on-disc tribological testing system in which the pin specimen is immersed in a simulated bio-fluid environment. Wear-induced weight loss (± 10 μg) and changes in surface roughness (± 0.001 μm) were obtained at 100,000 cycle intervals upto 500,000 cycles. Metallographic analysis was performed on the machined pin specimens to analyze the microstructure and microhardness before and after testing. The rate of wear for the specimens was lowest for those pins where the change of the subsurface microhardness was small due to prevention of additional steady state wear after the initial run-in wear in the wear tester. A combination or response surface methodology and genetic algorithm (GA) was used in to optimize the various machining parameters for minimized wear generation. The optimal combination of the four machining parameters (feed 0.18mm/rev, nose radius 0.6 mm, cutting speed 27.6 m/min and depth of cut 0.38) produced the largest compressive residual stresses on the surface and subsurface of the implants thereby reducing the wear/debris generation by about fifty percent.

Finite Element Simulation of Precision Cutting Monocrystalline Silicon

2013 ◽  
Vol 662 ◽  
pp. 99-102 ◽  
Author(s):  
Li Qiu Shi ◽  
Xiao Wen Li ◽  
Feng Yu
Keyword(s):  
High Surface ◽  
Cutting Speed ◽  
Monocrystalline Silicon ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Tool Edge Radius ◽  
Transition Mechanism ◽  
Edge Radius ◽  
Tool Edge ◽  
Optimization Of Cutting Parameters

Monocrystalline silicon is typical of hard brittle materials, a high surface quality can be obtained in ductile-regime cutting. The success of the turning process depends on optimizing the machining parameters such as the tool edge radius, tool rake angles, depth of cut and cutting speed, etc. In this study, based on the ductile–brittle transition mechanism, the optimization of cutting parameters were determined with the commercial, general purpose FEA software Msc.Marc. The result demonstrates that the value of temperature is minimum when the tool rake angle is in the range of -15º～-30º. Smaller tool edge radius was selected while maintaining quality of tool edge radius and tool life. As long as beyond the range of cutting speed 6 ~ 8 mm/s, smaller residual stress can be obtain.

scholarly journals The Experimental Investigation of Surface Roughness After Dry Turning of Steel S235

2019 ◽  
Vol 26 (4) ◽  
pp. 179-184
Author(s):  
Justyna Molenda
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Cutting Speed ◽  
Scientific Work ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Workpiece Material ◽  
Important Indicator

AbstractNowadays lot of scientific work inspired by industry companies was done with the aim to avoid the use of cutting fluids in machining operations. The reasons were ecological and human health problems caused by the cutting fluid. The most logical solution, which can be taken to eliminate all of the problems associated with the use of cooling lubricant, is dry machining. In most cases, however, a machining operation without lubricant finds acceptance only when it is possible to guarantee that the part quality and machining times achieved in wet machining are equalled or surpassed. Surface finish has become an important indicator of quality and precision in manufacturing processes and it is considered as one of the most important parameter in industry. Today the quality of surface finish is a significant requirement for many workpieces. Thus, the choice of optimized cutting parameters is very important for controlling the required surface quality. In the present study, the influence of different machining parameters on surface roughness has been analysed. Experiments were conducted for turning, as it is the most frequently used machining process in machine industry. All these parameters have been studied in terms of depth of cut (ap), feed rate (f) and cutting speed (vc). As workpiece, material steel S235 has been selected. This work presents results of research done during turning realised on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process results.

scholarly journals OPTIMASI PARAMETER PERMESINAN TERHADAP WAKTU PROSES PADA PEMROGRAMAN CNC MILLING DENGAN BERBASIS CAD/CAM

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
I G.N.K. Yudhyadi ◽  
Tri Rachmanto ◽  
Adnan Dedy Ramadan
Keyword(s):  
Cutting Speed ◽  
Operation Time ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Milling Machine ◽  
Cnc Milling ◽  
Cnc Milling Machine ◽  
Machining Parameter

Milling process is one of many machining processes for manufacturing component. The length of time in the process of milling machining is influenced by selection and design of machining parameters including cutting speed, feedrate and depth of cut. The purpose of this study to know the influence of cutting speed, feedrate and depth of cut as independent variables versus operation time at CNC milling process as dependent variables. Each independent variable consists of three level of factors; low, medium and high.Time machining process is measured from operation time simulation program, feed cut length and rapid traverse length. The results of statistically from software simulation MasterCam X Milling, then do comparison to CNC Milling machine.  The data from experiments was statistical analyzed by Anova and Regression methods by software minitab 16.Results show that the greater feedrate and depth of cut shorten the operation time of machinery, whereas cutting speed is not significant influence. Depth of cut has the most highly contribution with the value of 49.56%, followed by feedrate 43% and cutting speed 0.92%. Optimal time of machining process total is 71.92 minutes, with machining parameter on the condition cutting speed is 75360 mm/minutes, feedrate is 800 mm/minutes and depth of cut = 1 mm. Results of comparison time machining process in software Mastercam X milling with CNC Milling machine indicates there is difference not significant with the value of 0,35%.

Cutting forces analysis of micro-milling process on Inconel 718 – a finite element approach

2020 ◽  
Vol 11 (02) ◽  
pp. 2050011
Author(s):  
Padmaja Tripathy ◽  
Kalipada Maity
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Fem Analysis ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters

This paper presents a modeling and simulation of micro-milling process with finite element modeling (FEM) analysis to predict cutting forces. The micro-milling of Inconel 718 is conducted using high-speed steel (HSS) micro-end mill cutter of 1mm diameter. The machining parameters considered for simulation are feed rate, cutting speed and depth of cut which are varied at three levels. The FEM analysis of machining process is divided into three parts, i.e., pre-processer, simulation and post-processor. In pre-processor, the input data are provided for simulation. The machining process is further simulated with the pre-processor data. For data extraction and viewing the simulated results, post-processor is used. A set of experiments are conducted for validation of simulated process. The simulated and experimental results are compared and the results are found to be having a good agreement.

Multi Response Optimization of Setting Process Variables in Face Milling of ZE41 Magnesium Alloy using Ranking Algorithms and ANOVA

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
S.P. Sundar Singh Sivam ◽  
V.G. Umasekar ◽  
Ganesh Babu Loganathan ◽  
D Kumaran ◽  
K. Saravanan
Keyword(s):  
Cutting Speed ◽  
Chip Thickness ◽  
Numerical Control ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Setting Process ◽  
Order Preference ◽  
Tool Diameter ◽  
Cutting Point

This study presents the optimization of machining parameters on ZE41 Mg alloy fabricated by gravity die casting and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Focus on the optimization of machining parameters using the technique to get minimum surface roughness, cutting force, thermal stress, residual stress, chip thickness and maximum MRR. A number of machining experiments were conducted based on the L27 orthogonal array on computer numerical control vertical machining center. The experiments were performed on ZE41 using cutting tool of an ISO 460. 1-1140-034A0-XM GC3 of 20, 25 and 30mm diameter with cutting point 140 degrees, for different cutting conditions. TOPSIS and ANOVA were used to work out the fore most important parameters cutting speed, feed rate, depth of cut and tool diameter which affect the response. The expected values and measured values are fairly close. Finally, the study for optimizing machining process is surveyed and results show improvement in real experiments.

Optimisation of Machining Parameters for Milling Polyetheretherketones (PEEK) Biomaterial

2014 ◽  
Vol 699 ◽  
pp. 198-203 ◽  
Author(s):  
Raja Izamshah Raja Abdullah ◽  
Aaron Yu Long ◽  
Md Ali Mohd Amran ◽  
Mohd Shahir Kasim ◽  
Abu Bakar Mohd Hadzley ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Dimensional Precision ◽  
Good Surface

Polyetheretherketones (PEEK) has been widely used as biomaterial for trauma, orthopaedic and spinal implants. Component made from Polyetheretherketones generally required additional machining process for finishing which can be a problem especially to attain a good surface roughness and dimensional precision. This research attempts to optimize the machining and processing parameters (cutting speed, feed rate and depth of cut) for effectively machining Polyetheretherketones (PEEK) implant material using carbide cutting tools. Response Surface Methodology (RSM) technique was used to assess the effects of the parameters and their relations towards the surface roughness values. Based on the analysis results, the optimal machining parameters for the minimum surface roughness values were by using cutting speed of 5754 rpm, feed rate of 0.026 mm/tooth and 5.11 mm depth of cut (DOC).

scholarly journals The effects of machining residual stresses on springback in deformation machining bending mode

2021 ◽  
Author(s):  
Mohammad Reza Naghdi Sedeh ◽  
Abbas Ghaei
Keyword(s):  
Residual Stresses ◽  
Feed Rate ◽  
Complex Geometry ◽  
Cutting Speed ◽  
Raw Material ◽  
Depth Of Cut ◽  
Minor Effect ◽  
Wall Region ◽  
Thin Wall ◽  
Machining Parameters

Abstract Hybrid machining-forming technology is a combination of two thin-structural machining and incremental forming manufacturing processes. A group of complex geometry parts in which a thick region is connected to a thin wall region can be manufactured through this technology with certain advantages. The parts made by this technology require less raw material compared to the ones created by means of machining. The major problem with this technology is the dimensional and geometric inaccuracy of its products which is mainly due to springback. The main purpose of this research was to study the effects of machining parameters and residual stresses induced by the machining primary stage on the subsequent springback after the forming stage. It was found by experiments that the parameters of cutting speed, axial depth of cut, mode of milling and milling path had a minor effect on springback. However, the workpiece fracture during the forming stage was observed to be sensitive to the prior machining feed rate. Both finite element simulations and experimental results confirmed that the compressive machining residual stresses increased with an increase in the machining feed rate. The compressive residual stresses postponed the onset of fracture at the workpiece lower end during the forming stage. Therefore, we could approach the forming tool closer to the bottom of the wall during forming and, as a result, springback decreased considerably.

Residual Stress Evaluation in Machined Surfaces of Copper by Molecular Dynamic Simulation

2012 ◽  
Author(s):  
Yachao Wang ◽  
Chunhui Ji ◽  
Jing Shi ◽  
Zhanqiang Liu
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Component ◽  
Cutting Speed ◽  
Rake Angle ◽  
Tangential Direction ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Machined Surfaces

Residual stresses in machined surfaces are often regarded as a determining factor of component service life. However, little work has been conducted to investigate the distribution of residual stresses in machined surfaces at nano-scale. In this paper, an MD simulation study is performed to study the residual stresses in machined surfaces of single crystal copper by diamond tools. We adopt a fixed cutting speed of 400m/s, vary depth of cut from 0.5nm to 1.5 nm, and change the tool rake angle from −30° to +30°. The results are then compared and discussed in the following aspects. First, it is found that both tool rake angle and depth of cut affect the morphologies of the formed chips, and as well as the cutting force evolution during machining process. Second, the normal residual stress in the tangential direction is more significant and has a clearer pattern than those in other directions for all the simulation cases. As such, the focus of the study is on this particular stress component. Third, with the increase of depth of cut, the maximum tensile residual stress decreases, and the residual stress becomes compressive at a shorter distance into the machined surface. Also, the use of negative rake angle makes the residual stress overall more tensile when closer to surface, and more compressive as the depth into surface further increases. It is actually consistent with traditional metal machining theory. The use of negative tool rake angle requires a larger thrust force, and this in turn overall makes the residual stress more compressive.

Processing and End Milling Behavioural Study of A356-SiCp Composite

2012 ◽  
Vol 710 ◽  
pp. 338-343 ◽  
Author(s):  
K. Jayakumar ◽  
Jose Mathew ◽  
M.A. Joseph ◽  
R. Suresh Kumar ◽  
P. Chakravarthy
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
End Milling ◽  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Pressing Method ◽  
Reinforced Composite ◽  
Effect Of Particle Size

Machining process such as milling receives less attention in the study of machinability of composites due to its interrupted cutting and the complexity of the process. In the present study, A356 aluminium alloy powder reinforced with 10 volume % SiC particles of various sizes (1,12.5 and 25 µm) were synthesized by vacuum hot pressing method and the effect of particle size on the composites were analysed for its mechanical properties and machinability. End milling of these composites were carried out and the surface roughness and resultant cutting force were analysed with the change of machining parameters and varying SiC particle sizes. The minimum cutting force and surface roughness were obtained for a finer particle (1 µm) reinforced composite with higher cutting speed, low feed and depth of cut.

Evaluation of Surface Roughness and Cutting Forces During Precision Turning

2012 ◽  
Vol 622-623 ◽  
pp. 390-393 ◽  
Author(s):  
R. Vinayagamoorthy ◽  
M. Anthony Xavior
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Working Conditions ◽  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Medical Implants ◽  
Machining Processes ◽  
Precision Turning

The Ti-6Al-4V titanium alloy is commonly used in aerospace, automotive industries and for manufacturing of medical implants, due to its biocompatibility. The objective of this work is to investigate the performance of precision turning using conventional lathe on Ti6Al4V under dry working conditions. A range of parameters that involve the machining processes were recognized and a consensus was reached to finalize its values. The proposed work is to carry out machining under the selected levels of parameters to evaluate the cutting force and surface roughness generated as the consequence of the machining process. Cutting speed, feed rate, depth of cut and nose radiuses are considered as the machining parameters for experimentation. The variation in the surface roughness and the cutting force for the variation of each machining parameters are presented graphically.

Sign in / Sign up

Export Citation Format

Share Document