Abrasive Finishing Process Research Articles

Multiobjective optimization of magnetic abrasive finishing process with periodic re-distribution of magnetic abrasive particles on 17-4PH stainless steel

Magnetic abrasive finishing (MAF) exhibits considerable potential as a promising process for enhancing surface finish quality for softer as well as harder materials. This work proposes a novel approach to harness the potential of MAF for obtaining superior surface quality of precipitation-hardening martensitic steel (17-4PH steel) while performing periodic re-distribution of magnetic abrasive particles. The experiments were conducted using the Box-Behnken design of experiments and response surface methodology (RSM). RSM-based desirability function approach and genetic algorithms were used for multiobjective optimization. The set of pareto-optimal solutions obtained through multiobjective optimization were ranked using the Technique for Order of Preference by Similarity to an Ideal Solution (TOPSIS) by assigning equal importance to the selected performance parameters (percentage change in surface roughness (PCSR) and material removal rate (MRR)). The optimized values of PCSR and MRR obtained through the desirability function of RSM and genetic algorithm were validated experimentally and compared with the predicted values obtained through the regression model. Results showed that the desirability function of RSM provided better results than the genetic algorithm for the selected conditions and confirmed the effectiveness of the proposed approach.

Experimental investigation on the surface topographical improvement of selective laser melted SS316L using abrasive flow finishing

Selective laser melting (SLM) offers a precise fabrication of intricate geometries that are not achievable with conventional manufacturing processes. However, surface imperfections like adhered powder particles, waviness, and other anomalies impede the intended functional application and demand additional post-processing steps. Abrasive flow finishing (AFF) process is extensively used for enhancing the surface topography of SLM-built parts by reciprocating a viscoelastic polymer abrasive medium. The cost of commercial abrasive media is expensive, needs costlier and heavy equipment, has little tolerability, and releases hazardous gases during its preparation. In this work, a biopolymer-based abrasive media is developed in-house and employed to examine the surface topographical changes of SLM-built SS316L flat features. Compared to commercial abrasive media, the cost of the developed abrasive media is much lower, does not require expensive equipment, and is eco-friendly. The effect of extrusion pressure, number of finishing cycles, and size of the abrasive particles on the percentage change in areal surface roughness (%ΔSa) and waviness (%ΔWa) was studied. From the analysis of variance, irrespective of %ΔSa and %ΔWa, it was found that the number of cycles was the most contributing process parameter, followed by extrusion pressure and abrasive particle size. The optimised process parameters resulted in a maximum %ΔSa and %ΔWa of about 90.1 % and 66.25 %, respectively, from the initial as-built areal surface roughness of 6.6 ± 0.2 μm and areal surface waviness of 7.7 ± 0.4 μm.

MAF process for aluminum 6060: An analytical temperature modelling and chemo-mechanical analysis

The magnetic abrasive finishing process is a sophisticated micro-finishing process that enhances the surface quality of superalloys, ceramics, and composites. Surface temperature plays a pivotal role in facilitating chemo-mechanical reactions between the processed surface and abrasive particles. In triggering the chemo-mechanical response of the micro-finished surface of Aluminum 6060 (Al-6060), an analytical thermal model derived using Jaeger moving heat formulation to find the flash temperature (FT) and flash time duration (FTD) at the micro-finishing interface of the processed workpiece and the abrasive particles of the magnetic abrasive brush. Furthermore, the present work performed an RSM-based Box Behnken design experiment to analyse and explain the crucial role of machining gap, abrasive weight, Voltage, and rotational speed on surface temperature, machining surface, and hardness. ANOVA highlighted key factors in machining responses. Surface roughness and temperature were notably influenced by voltage (58.42 % and 57.62 %, respectively), while surface hardness primarily depended on abrasive weight (60.65 %). Using the developed model, extreme FT of 880 °C and 810 °C were calculated under specific conditions, along with corresponding FTD required for quasi-steady-state conditions. FT and FTD were identified as sufficient for initiating chemo-mechanical action in the MAF micro-finishing process, depending on contact pressure, the number of abrasive particles, and sliding velocity, which in turn are influenced by magnetic intensity, abrasive ratio, and rotational speed. Furthermore, a detailed examination of the finished surface was carried out using the SEM, EDS and XRD of Al-6060 which shows that the SiC does participate on the finishing surface. Chemical substrates such as Kaolinite (Al2O9Si2), Iron silicide (FeSi), and Cristobalite (O2Si) had formed on the finished surface of Al-6060 due to the chemo-mechanical action between the SiC and workpiece material.

Achieving in-situ Fe-based spherical particles for magnetic abrasive finishing process of Zirconium tube via gas nitriding method

The magnetic abrasive powders have great influence on the magnetic abrasive finishing accuracy and efficiency. A new kind of Fe-based spherical magnetic abrasive particles with Fe2N precipitates and Fe4N matrix was successfully synthesized by gas nitriding. The results show that the prepared Fe-based magnetic abrasive particles can reduce the roughness of the Zirconium tube from 0.325 to 0.154 μm by four MAF passes. The high hardness and wear resistance of the Fe-based magnetic abrasive particles are assessed based on the Vickers hardness and nanoindentation results. This study can provide theoretical and experimental support for fabricating high-performance magnetic abrasive particles.

Study on temperature and hardness behaviors of Al-6060 alloy during magnetic abrasive finishing process using artificial neural networks

Magnetic Abrasive Finishing (MAF) revolutionizes surface finishing by utilizing magnetic fields to apply pressure, ensuring exceptionally high-quality surfaces. Its potential for ultra-precise finishing with fine magnetic abrasives is particularly noteworthy. This study analyzes subsurface temperature dynamics during the MAF process on Al-6060, recognizing temperature's pivotal role in shaping surface texture and mechanical-chemical properties. Unbonded magnetic abrasives containing SiC were used without lubrication or coolants in experimentation. Experimental parameters, including machining gap, abrasive weight, voltage, and rotational speed, were systematically varied using a Box-Behnken Design of Experiments. An artificial neural network facilitated comprehensive data modelling, enabling a detailed parametric study. Post-processing surface characterization provided crucial insights into the impact of surface temperature rise on surface finish and hardness. This holistic approach enhances understanding of temperature's influence on MAF efficacy and its outcomes on Al-6060 surfaces. Experimental findings demonstrate MAF's effectiveness in achieving low-temperature finishing of Al-6060, with a maximum surface temperature of 36 °C. ANOVA analysis quantitatively determined that voltage has greatest influence (55.56%), followed by abrasive weight (20.00%) and machining gap (13.89%), with rotational speed having the least impact (2.22%). Qualitatively, the developed ANN model accurately predicted changes in surface roughness (ΔRa), temperature (ΔT), and hardness (ΔH), with maximum errors of 4.107%, 5.588%, and 6.680%, respectively. XRD analysis provided quantitative evidence of SiC diffusion into the surface, resulting in a hardness increase from 2.7 HV to 5.6 HV. Additionally, chemical substrates deposition, such as silicon carbide, kaolinite, iron silicide, and cristobalite, elucidated chemical-mechanical interactions during the process at such low temperatures.

Fuzzy Logic Based Model to Predict Surface Roughness of Si(100) Wafer Using Preliminary Experimental Data Obtained From Single Pole Magnetic Abrasive Finishing Process

Fuzzy Logic Based Model to Predict Surface Roughness of Si(100) Wafer Using Preliminary Experimental Data Obtained From Single Pole Magnetic Abrasive Finishing Process

Optimizing the five magnetic abrasive finishing factors on surface quality using Taguchi-based grey relational analysis

The effectiveness of the magnetic abrasive finishing (MAF) process relies on several factors, including the brush’s flexibility that varies across tools. This study aimed to optimize the results of five key parameters (voltage, finishing time, gap distance, rotating speed, and particle size) on surface roughness (SR) and microhardness (HV) using the grey relational analysis (GRA) method. Experimental work employed the Taguchi design with L27 trials in Minitab 17, involving five variables with three levels for each. The impact of these parameters on microhardness and surface roughness for stainless steel SUS420 bubble cups was assessed using Taguchi and regression analyses. The best roughness improvement and the most substantial enhancement in microhardness were individually obtained with the GRA method. This method assigned the best results for both surface roughness and microhardness. According to Taguchi analysis, the voltage parameter has the main or maximum parameter effect on grade, followed by gap distance, time, spindle speed, and particle size. It was found that the optimal parameters were the same as the input parameters.

Surface Polishing of an Inconel 625 Bar by a Super-Fast MAF Process for a Solenoid Valve Stem Used in a Hydrogen Tank

This study explores a super-fast magnetic abrasive finishing (MAF) process for polishing the surface of an Inconel 625 bar workpiece for a hydrogen solenoid valve stem. The Inconel 625 bar was chosen to replace the existing STS 316 bar material, previously used for a hydrogen solenoid valve stem. The cylindrical surface of Inconel 625 bars was polished by a super-fast MAF process with high rotational speeds of 1000, 5000, 15,000, and 25,000 RPM and a super-strong magnetic field of 550 mT. The polishing characteristics of this process were evaluated according to the type of abrasives, rotational speeds of the workpiece and processing time. As a result, a super-smooth Inconel 625 bar was successfully achieved, with a surface roughness (Ra) reduced from 0.31 μm to 0.02 μm under the optimal conditions (15,000 RPM, CNT particles (0.04 μm), PCD diamond abrasive (1 μm), Fe (#200), 0.5 g of light oil, and 16 min of processing time). Also, the Ansys analysis results showed suitable strain, equivalent stress, and safety factor of the Inconel 625 bar. This confirmed that, after a super-fast MAF process, an Inconel 625 bar is feasible for application in Hydrogen (H2) tanks instead of a conventional STS 316 bar.

Measurement from the residual stresses on magnetic abrasive finishing process by utilizing steel sheet 201

Measurement from the residual stresses on magnetic abrasive finishing process by utilizing steel sheet 201

The Impact of Magnetic Abrasive Finishing (MAF) Process Parameters on the Microhardness of Stainless Steel SUS420 Bubble Cups

The Impact of Magnetic Abrasive Finishing (MAF) Process Parameters on the Microhardness of Stainless Steel SUS420 Bubble Cups

Development and experimentation of free-form magnetic abrasive finishing process for the application of bearing surfaces

Development and experimentation of free-form magnetic abrasive finishing process for the application of bearing surfaces

Development and experimentation of Free-form Magnetic abrasive finishing process for the application of bearing surfaces

Development and experimentation of Free-form Magnetic abrasive finishing process for the application of bearing surfaces

INVESTIGATION OF SURFACE ROUGHNESS IN MODERN FINISHING PROCESS USING PERMANENT MAGNET

This work introduces an investigation of the surface roughness (Ra) during flat plate machining utilizing magnetic abrasive finishing process (MAF). In this study three parameters (Machining time, Mesh size, and Gap) were studied. The MAF tool is made from permanent magnet and the abrasive powder is consisting of 40% of SiC and 60% Fe powder with three Mesh size (100, 250, and 400 µm). The Taguchi L9 array was used in designing the experiments. The results show that the increasing machining time caused a decrease in Ra. The increase in mesh size and the gap will increase the surface roughness. The dominant factor that affect the surface roughness was the machining time due to enough time to machine the target surface.

Experimental comparison of unbonded, agglutinated and sintered SiC-based magnetic abrasive particles in magnetic abrasive finishing process

Aluminum grabs a spot in the top ten light metals and henceforth finds a wide range of applications in the aerospace industry and other concerned/allied industries. A high surface finish is obligatory in a few components. The objective of this research is to compare and analyze the internal surface finish obtained by unbonded, agglutinated, and sintered silicon carbide (SiC) based magnetic abrasives in aluminum pipes using magnetic abrasive finishing process. Scanning electron microscopy and atomic force microscopy (AFM) have aided in a close inspection of the topography of the surfaces. AFM topographic images indicate that sintered magnetic abrasive particles yielded a surface roughness value (Ra = 17.7 nm) followed by agglutinated (Ra = 34.98 nm) and unbonded magnetic abrasive particles (Ra = 99.3 nm). Maximum percentage improvement in surface finish (PISF) of 87 % in terms of Ra has been obtained at rotational speed of workpiece (1000 rpm), magnetic flux density (0.85 Tesla), quantity of abrasive particles (15 gm), size of abrasives (80 μm) and machining time (30 mins.).

Effect of ground tire rubber media's viscoelasticity and flow passage geometry on the abrasive flow finishing of helical gear

This work aims to elucidate the behavior of viscoelastic ground tire rubber media (GTRM) under abrupt contraction and expansion of the media at the entry and exit of the gear flow channel and its influence on polishing results. Due to the inherent nature of the abrasive flow finishing (AFF) process, the media flow converges at the entrance of the gear tooth as it flows from a larger fixture cross-section to a narrower volumetric space between gear teeth. The material removal and subsequent surface roughness rely heavily on the flow's pressure and velocity. A numerical simulation was performed to obtain the pressure and velocity along the gear flank face width (FFW). To investigate the effect of variation in the media deformation rate along the gear flow channel on AFF results, the material removal height and improvement in average surface roughness at different locations along the tooth flank face width were measured. AFF results reveal that the material removal near the two edges of the gear tooth is higher and has an inferior surface finish compared to the tooth's center. Due to the abrupt compression of the media at the flow channel entrance, the media act elastically dominant, resulting in high pressure and flow velocity near the tooth edge (flow channel's entry). Additionally, the effect of the helix angle on the AFF of various helical gear (HG) was investigated. Among the three HGs chosen, the 30° HG produces the lowest surface roughness under moderate pressure and high velocity. The microhardness and fretting wear analyses further confirm that the AFF polishing increases the microhardness and wear resistance of the gear tooth surface as a result of work hardening and minimizing surface defects.

A novel auto-gaping magnetic pole system for inner surface finishing of non-circular pipes using magnetic abrasive finishing process

This study explored the design of a novel auto-gaping magnetic pole system for finishing the inner surface of non-circular pipes using a magnetic abrasive finishing (MAF) process. Non-circular pipes are widely used for the transportation of ultra-high purity substances, including gases and fluids in many industries for semiconductor, medical, and aerospace applications. MAF process typically utilizes non-movable magnetic poles. However, due to the noncircular cross-section of the pipe, the magnetic flux density, produced by non-movable magnetic poles, across the polishing surface will exhibit huge variations, resulting in uneven and poor finish at some areas. The proposed auto-gaping magnetic pole system allows the magnetic poles to move so that they can track the workpiece surface to keep the gap between the magnetic pole and workpiece’s external surface constant. As a result, the magnetic densities can be maintained at desired values to achieve even and effective finishing by MAF process. Elliptical pipes were used as the non-circular pipes for experimental validation under different MAF process parameters. The results showed that this novel technique for inner surface finishing of a non-circular pipe is capable of improving the surface roughness, reducing the Ra values from over 0.20 μm to 0.05 μm or lower, across the entire inner surface of the elliptical pipe. In addition, superior material removal efficiency was achieved. The results demonstrate that the MAF process combined with a novel auto-gaping magnetic pole system is feasible to produce the ultra-smooth inner surface of non-circular pipe.

Experimental Investigations of Nano Finishing Process on Nickel-Free Austenitic Stainless Steel by Grey Relational and Principal Component Analysis

The nano surface roughness of metallic materials is important in engineering and medical fields for specific applications. Magneto rheological abrasive flow finishing (MRAFF) process was performed on nickel-free austenitic stainless workpieces in order to obtain surface roughness at the nano level and also to forecast the performance of the MRAFF process in terms of responses such as surface roughness (SR) and material removal rate (MRR). These two responses are affected by process factors such as hydraulic pressure, current to the electromagnet, and the number of cycles performed during the machining process. The design of experiments (DOE) was used to determine the contributions of process parameters to output responses. The techniques of grey relational analysis (GRA) and principal component analysis (PCA) were used in these experimental investigations to discover the process factors that minimise the final Ra and maximise MRR. Through the DOE, a minimum SR of 63.24 nm and a maximum MRR of 2.34 mg/sec were obtained on the samples for the combination of 30 bar pressure, 6 A current, and 300 number of cycles.

Nanoscale Polishing Technique of Biomedical Grade NiTi Wire by Advanced MAF Process: Relationship between Surface Roughness and Bacterial Adhesion.

Nitinol (NiTi), an alloy of nickel and titanium, wires are an important biomedical material that has been used in catheter tubes, guidewires, stents, and other surgical instruments. As such wires are temporarily or permanently inserted inside the human body, their surfaces need to be smoothed and cleaned in order to prevent wear, friction, and adhesion of bacteria. In this study, NiTi wire samples of micro-scale diameters (i.e., Ø 200 μm and Ø 400 μm) were polished by an advanced magnetic abrasive finishing (MAF) process using a nanoscale polishing method. Furthermore, bacterial adhesion (i.e., Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus)) to the initial and final surfaces of NiTi wires were investigated and compared in order to assess the impact of surface roughness on bacterial adhesion to the surfaces of NiTi wires. The finding revealed that the surfaces of NiTi wires were clean and smooth with a lack of particle impurities and toxic components on the final surface polished using the advanced MAF process. The surface roughness Ra values of the Ø 200 μm and Ø 400 μm NiTi wires were smoothly enhanced to 20 nm and 30 nm from the 140 nm and 280 nm initial surface roughness values. Importantly, polishing the surfaces of a biomedical material such as NiTi wire to nano-level roughness can significantly reduce bacterial adhesion on the surface by more than 83.48% in the case of S. aureus, while in the case of E. coli was more than 70.67%.

A new theoretical model for surface roughness prediction in rotational abrasive finishing process

Rotational abrasive finishing (RAF) is a new nano-finishing technique in which the finishing forces are applied to the workpiece by the opposite rotations of a stirring-blades and the workpiece. The RAF process allows for finishing the inner and outer surfaces of workpieces, particularly complex ones with axial symmetry. The present study aims to propose a new theoretical model to obtain deeper insights into the material removal mechanism, surface roughness prediction, and forces in RAF process. Since the abrasive-workpiece interaction is random and complex in nature in the RAF, some initial assumptions were considered. To validate the repeatability of the experimental results, the experiments were designed based on the Response surface method (RSM). To validate the new proposed theoretical model, a number of influential parameters were investigated. It was found that the stirring-blade speed (S), working gap (W), and abrasive grain size (A) had significant effects on Ra. The minimum surface roughness (Ra) was obtained to be 46.87 nm at a rotational speed of 600 rpm, a working gap of 1 mm, and grain size of 18 μm. The experimental results were relatively in good agreement with the theoretical results so that the maximum error was about 24%. This can be assumed that the most important explanation for the difference between the theoretical and experimental results can be attributed to the initial theoretical assumptions.

Ultrasonic assisted magnetic abrasive finishing of DIN 1.2738 tool steel using vitrified bonded magnetic abrasive particles

Ultrasonic-assisted magnetic abrasive finishing (UAMAF) process has been developed to reduce the finishing time of hard materials. In this process, in addition to the rotation of the magnetic tool, ultrasonic vibrations are also applied to the workpiece simultaneously in the longitudinal direction. In the present work, the effects of UAMAF process parameters, including ultrasonic power, the rotational speed of the magnetic tool, working gap, and weight of magnetic abrasive particles (MAPs) on the percentage change in surface roughness (%ΔRa) of 1.2738 tool steel are discussed with an experimental approach. In this regard, besides the development of the UAMAF process, the sintering of MAPs with glass powder is proposed. The experiments are designed according to the Taguchi method. Then, the input parameters of the UAMAF process are modeled and optimized using the signal-to-noise (S/N) ratio analysis to achieve the maximum %ΔRa. Statistical analysis of experimental data shows that the most significant contribution in improving %ΔRa is attributed to the weight of MAPs. Furthermore, according to the comparative study, %ΔRa in the UAMAF process for finishing the DIN 1.2738 tool steel is improved by 86.62% under optimized conditions. In comparison, this value in the MAF process is equal to 48.62% under the same conditions. The results of the surface morphology also underline that abrasive particles in the UAMAF process hit the peaks of the surface roughness due to vibration applied to the workpiece, which leads to a high-quality finished surface.