Experimental, Theoretical, and Simulation Comparative Study of Nano Surface Roughness Generated During Abrasive Flow Finishing Process

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Sachin Singh ◽  
Deepu Kumar ◽  
Mamilla Ravi Sankar
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Simulation Model ◽  
Abrasive Particle ◽  
Complex Surface ◽  
Abrasive Medium ◽  
Finishing Process ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Abrasive flow finishing (AFF) is one of the advanced finishing processes used mainly for finishing of complex surface features. Nano finishing of aluminum alloys is difficult using conventional finishing processes because of its soft nature. So, in this work, aluminum alloys are finished using AFF process. Since the finishing is carried out using polymer rheological abrasive medium (medium), the finishing forces on aluminum alloy workpieces are too low compared to conventional finishing processes. Thus, this process generates nano surface roughness on aluminum alloy. By using the theoretical model, change in surface roughness (ΔRa) with respect to various AFF input parameters is studied. A new simulation model is proposed in this paper to predict the finishing forces and ΔRa during AFF process. Modeling of finishing forces generated during the AFF process is carried out using ansys polyflow. These forces are used as input in the simulation model to predict ΔRa. Medium rheology decides the magnitude of the generated finishing forces in AFF process. Therefore, to predict the forces accurately, rheological properties of the medium are measured experimentally and used as input during modeling. Further, to make the simulation more realistic, abrasive particle bluntness with respect to extrusion pressure and number of strokes is considered. Because of considering these realistic conditions, simulation and experimental results are in better agreement compared to theoretical results.

Development of polymer abrasive medium for nanofinishing of microholes on surgical stainless steel using abrasive flow finishing process

2019 ◽  
Vol 234 (3) ◽  
pp. 355-370 ◽  
Author(s):  
Sachin Singh ◽  
M Ravi Sankar
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
High Surface ◽  
Machining Process ◽  
Abrasive Medium ◽  
Finishing Process ◽  
Drug Eluting ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

The finishing operation completes the manufacturing cycle of a component. Depending on the level of finish (micro and nano) required on the component surface, different finishing processes are employed. Several components employed in medical, automotive and chemical industries use different types of passages for the flow of fluid. The surface roughness of such passages decides the functionality of the component. Drug-eluting stents are one of the recent advancements in the medical industry. They possess microholes for release of the drugs to the point of cure. Microholes are mostly fabricated by thermal-based micromachining processes that generate metallurgically destroyed surface layers with high surface roughness. Later, these are polished using chemical or electrochemical polishing techniques, which chemically destroy the quality of the surface. These metallurgically and chemically modified (destroyed/changed) rough surfaces on the microhole wall can cause contamination of the drug. So in this article, microholes of diameter 850 ± 30 µm are fabricated in surgical stainless steel (SS 316L) workpieces using the electric discharge micromachining process. Machined microholes are finished by employing a non-traditional finishing process called the abrasive flow finishing process. Instead of using a commercially available expensive abrasive flow finishing medium, the economic medium is fabricated in-house, and its rheological study is carried out. Machining process produces microholes with a surface roughness of about 1.40 ± 0.10 µm. Later, by finishing of microholes with the abrasive flow finishing process, the surface roughness is reduced to 150 nm (percentage surface roughness improvement of about 88.53%). Therefore, the abrasive flow finishing process is a viable alternative to chemical-based polishing processes as it removes the recast layer and achieves nanosurface roughness.

Development and Rheological Characterisation of Abrasive Flow Finishing Medium for Finishing Macro to Micro Features

2020 ◽  
Vol 70 (2) ◽  
pp. 190-196
Author(s):  
Sachin Singh ◽  
M. Ravi Sankar
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Recast Layer ◽  
Technological Advancement ◽  
Minimal Cost ◽  
Finishing Process ◽  
Fine Surface ◽  
Micro Features ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Technological advancement demands the manufacturing of components with a fine surface finish at a minimal cost. This scenario acts as the driving force for the research communities to develop economic finishing processes. Abrasive flow finishing (AFF) is one of the advanced finishing processes employed for finishing, deburring, radiusing and recast layer removal from the workpiece surfaces. AFF process uses a finishing medium that acts as a deformable tool during the finishing process. It is the rheological properties of the medium that profoundly influences the end surface finish obtained on the workpiece after the AFF process. In the current work, an attempt is made to develop an economic AFF medium by using viscoelastic polymers i.e., soft styrene and soft silicone polymer. Detailed static and dynamic characterisation of the medium is carried out. Later, to study the finishing performance of the developed medium, AFF experiments are performed for the finishing of macro and micro feature components. The experimental study showed that the nano surface finish could be achieved by varying the viscosity of the developed medium. Developed medium achieved 89.06 per cent improvement in surface roughness during finishing of tubes (macro feature component), while 92.13 per cent and 88.11 per cent surface roughness improvement is achieved during finishing of microslots and microholes (micro feature component), respectively.

Optimal parameters of abrasive flow finishing for hip joint implants

2021 ◽  
pp. 095440542199561
Author(s):  
Yahya Choopani ◽  
Mohsen Khajehzadeh ◽  
Mohammad Reza Razfar
Keyword(s):  
Surface Roughness ◽  
Standard Deviation ◽  
Femoral Head ◽  
Hip Joint ◽  
Spherical Shape ◽  
Shape Deviation ◽  
Head Surface ◽  
Joint Implants ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Total hip arthroplasty (THA) is one of the most well-known orthopedic surgeries in the world which involves the substitution of the natural hip joint by prostheses. In this process, the surface roughness of the femoral head plays a pivotal role in the performance of hip joint implants. In this regard, the nano-finishing of the femoral head of the hip joint implants to achieve a uniform surface roughness with the lowest standard deviation is a major challenge in the conventional and advanced finishing processes. In the present study, the inverse replica fixture technique was used for automatic finishing in the abrasive flow finishing (AFF) process. For this aim, an experimental setup of the AFF process was designed and fabricated. After the tests, experimental data were modeled and optimized to achieve the minimum surface roughness in the ASTM F138 (SS 316L) femoral head of the hip joint through the use of response surface methodology (RSM). The results confirmed uniform surface roughness up to the range of 0.0203 µm with a minimum standard deviation of 0.00224 for the femoral head. Moreover, the spherical shape deviation of the femoral head was achieved in the range of 7 µm. The RSM results showed a 99.71% improvement in the femoral head surface roughness (0.0007) µm under the optimized condition involving the extrusion pressure of 9.10 MPa, the number of finishing cycles of 95, and SiC abrasive mesh number of 1000.

Effect of Abrasive Medium Ingredients on Finishing of Al Alloy and Al Alloy/SiC Metal Matrix Composites Using Rotational Abrasive Flow Finishing

2011 ◽  
Vol 110-116 ◽  
pp. 1328-1335 ◽  
Author(s):  
M. Ravi Sankar ◽  
V.K. Jain ◽  
Janakarajan Ramkumar
Keyword(s):  
Chemical Change ◽  
Cumulative Effect ◽  
Volume Ratio ◽  
Al Alloy ◽  
Matrix Composites ◽  
Abrasive Medium ◽  
Polymer Volume ◽  
Sic Composites ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Al alloy/SiC composites possess better mechanical and physical properties thus finding applications in automotive, sports, and aerospace. In some cases, these components require nanolevel finished surface. But, traditional abrasive finishing processes are labor intensive, time consuming and confined to only simple geometries. Abrasive flow finishing (AFF) is one of the advanced finishing processes that can be used to finish complex surfaces by flowing polymer based abrasive medium but its finishing rate is low. In the present work, Rotational-AFF (R-AFF) process is developed where in workpiece rotates about its axis. This rotation provides the dynamic motion (additional force and velocity components) to the workpiece. By cumulative effect of workpiece rotation and medium reciprocation, the active abrasive particles try to abrade the workpiece in a helical path. Thus, finishing length and finishing rate both increase. In AFF process, because of more finishing time medium undergoes chemical change or degradation (loses its viscosity) because of continuous shearing and rise in temperature. Therefore the effect of medium shear viscosity variation with the temperature is studied to understand how the viscosity reduces with the temperature. Later complete experiments are conducted on R-AFF process by varying plasticizer to polymer volume ratio and polymer to abrasive ratio. The finishing from micron surface topography to nanosurface topography is studied using atomic force microscopy.

Analysis of Forces During Spot Finishing of Titanium Alloy Using Novel Tool in Magnetic Field Assisted Finishing Process

2018 ◽  
Author(s):  
Anwesa Barman ◽  
Manas Das
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Normal Force ◽  
Tangential Force ◽  
Abrasive Particle ◽  
Initial Surface ◽  
Precise Control ◽  
Percentage Improvement ◽  
Finishing Process

Magnetic field assisted finishing process is a nanofinishing process which uses magnetic field for precise control of finishing forces. Magnetorheological fluid mixed with diamond abrasive particles in base medium of glycerol, hydrofluoric acid, nitric acid, and deionized water is used as the polishing medium. The novel tool is a magnet fixture made of mu-metal which is used to hold the magnet during finishing. In the present experimental study, finishing at a spot on flat titanium alloy is carried out to analyze the forces involved in the finishing. Normal force is the main force responsible for the indentation by the abrasive particle on the workpiece surface. Tangential force helps in removing indented material. The measured normal force and tangential force during the spot finishing are 3.285 N and 0.43 N, respectively. The final surface roughness achieved after spot finishing is 10 nm from initial surface roughness of 200 nm. The percentage improvement in surface roughness is 95%.

Tool Wear of Diamond-Like Carbon-Coated High-Speed Steel with a Cr-Based Interlayer in Cutting of Aluminum Alloys

2012 ◽  
Vol 152-154 ◽  
pp. 74-79
Author(s):  
Tadahiro Wada ◽  
Koji Iwamoto ◽  
Hiroaki Sugita
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Tool Wear ◽  
High Speed ◽  
High Speed Steel ◽  
Diamond Like Carbon ◽  
Aluminum Alloy 6061 ◽  
Coated Tool ◽  
Alloy 6061

In cutting aluminum alloy 6061, continuous chips have a negative influence on the machining operation. Usually, Pb is added in order to break continuous chips. However, from the standpoint of environmental protection, it is necessary to improve chip breakability without adding Pb. One effective measure to improve chip breakability is by adding Si to aluminum alloy 6061. However, the influence of Si content on tool wear has not been fully examined. In this study, in order to clarify the influence of a diamond-like carbon (DLC) coating layer with a Cr-based interlayer, namely (Al,Cr)N, on cutting performance, aluminum alloys having different Si contents were turned. The substrate of the tool material was high-speed steel (1.4%C). The tool wear and the surface roughness were experimentally investigated. The following results were obtained: (1) In cutting two kinds of Al-Si alloys, namely the Al-2%Si alloy and Al-4%Si alloy, the progress of wear of the DLC/(Al,Cr)N-coated tool was slower than that of the DLC-coated tool. Therefore, the (Al,Cr)N interlayer was effective for decreasing the tool wear of the DLC-coated tool. (2) The wear progress of the two kinds of DLC-coated tools in cutting of Al-4%Si alloy was faster than that in cutting of Al-2%Si alloy. (3) In cutting of Al-2%Si alloy with the (Al,Cr)N/DLC-coated tool, the surface roughness was almost constant in the range of a cutting distance from 0.1 km to 9.5 km.

Researches Regarding the Influence of Cutting Regime on Processed Surface in Aluminum Alloys Turning Process

2015 ◽  
Vol 808 ◽  
pp. 15-20
Author(s):  
Adrian Trif ◽  
Marian Borzan ◽  
Alexandru Popan ◽  
Domniţa Fraţilă ◽  
Adriana Rus ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Statistical Method ◽  
Surface Quality ◽  
Feed Rate ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Turning Process

The main purpose of this paper is to analyze the influence of cutting regime parameters in case of dry turning of an aluminum alloy. For turning process of the aluminum alloy was used Sandvik insert DCGX 11 T3 08 Al H10. The influence of the main cutting parameters on the surface quality was analyzed using a statistical method (ANOVA) used to test differences between two or more means. Based on a mathematical model can be calculated the surface roughness taking into account the cutting speed, the feed rate and the depth of cutting.

Efficient Finishing of Laser Beam Melting Additive Manufactured Parts

2021 ◽  
Vol 5 (4) ◽  
pp. 106
Author(s):  
Henning Zeidler ◽  
Rezo Aliyev ◽  
Florian Gindorf
Keyword(s):  
Surface Roughness ◽  
Laser Beam ◽  
Functional Performance ◽  
Process Chain ◽  
Optimal Parameters ◽  
Laser Beam Melting ◽  
Finishing Process ◽  
Plasma Electrolytic ◽  
Finishing Processes ◽  
Process Combination

In many cases, the functional performance of additively manufactured components can only be ensured by finishing the functional surfaces. Various methods are available for this purpose. This paper presents a procedure for selecting suitable processes for finishing laser beam melting additive–manufactured parts which is ultimately based on technological knowledge. It was experimentally proven that the use of several consecutive finishing processes is beneficial to achieve better surface quality. One finishing process chain was particularly effective (namely particle blasting/vibratory grinding/plasma electrolytic polishing) and the technological limits of this method were investigated in this study. The optimal parameters for this process combination ensured a surface roughness Sa < 1 µm.

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