Abrasive Flow Machining Process Research Articles

Parametric investigation of thermal additive centrifugal abrasive flow machining process for enhancing productivity

Thermal additive centrifugal abrasive flow machining hybrid of abrasive flow machining caters to low material removal issues which enhances the acceptability of the process. The present investigation investigates the different centrifugal force-generating electrode geometry performances in the thermal additive centrifugal abrasive flow machining process. The L27 orthogonal array is used for optimizing the process parameters (electrode type, current supply, and the duty cycle) and their effect on material removal and percentage improvement in surface finish (%Δ Ra) are analyzed. Based on the percentage contribution obtained from Taguchi analysis, electrode type is the prominent parameter for material removal (88.27%) and %Δ Ra (78.54%) followed by current (7.43% for material removal and 13.92% for %Δ Ra) and duty cycle (3.95% for material removal and 6.42% for %Δ Ra). The spline electrode with a curved blade is found optimum with 10 A current and 0.76 duty cycle. The average experimental value based on the design of the experiment and the predicted value for material removal is 10.373 and 10.881 mg, respectively. The average experimental value and the predicted value for percentage improvement in the surface are 42.24% and 43.71%, respectively. The percentage error between the predicted and experimental values for material removal and %Δ Ra is 4.66% and 3.15%, respectively.

A State-of-the-Art Review on the Recent Advancements in the Electrochemical Abrasive Flow Machining Process

Abrasive flow machining (AFM) is a non-conventional machining method used for the fine finishing of complex external/internal surfaces of metallic parts. Generally, this process has a low material removal rate (MRR) and is a more time-consuming process. So, to overcome this problem, various researchers employed hybridization of the abrasive flow machining process (AFM) with a distinct nontraditional machining process. Hence, this paper aims to provide a detailed review of the electro-chemical assisted AFM (ECA2FM) process, which is a combination of electrochemical machining and abrasive flow process. Then, the effect of processing parameters such as grit size and type, the total number of cycles, current, voltage, abrasive type and size, extrusion pressure, design of workpiece holding device and proper tooling on the material abrasion and surface finishing is summarized. Thereafter the Progressive outlook on the integration of electrochemical AFM with magnetic energy is given. Finally, the emerging applications of the electrochemical AFM process are discussed.

Review of surface roughness and material removing rate on abrasive flow machining process

Every day, advancements in manufacturing technology research and innovation yield a highly finished surface with lower labour and machining costs. The conventional materials that were frequently employed in the chemical, automotive, and aerospace industries have been replaced by materials like ceramics, metal matrix composites, polymers, and super alloys. The AFM technology is capable of maintaining precision, reliability, and adaptability across adverse range of applications. Internal parts, through holes, intersecting holes, and freeform surfaces that are challenging to finish with other conventional finishing techniques can all be polished and deburred with AFM. The current study aims to determine the process variables that have a major impact on the change in surface roughness of the inner, outer, and side surfaces as well as the amount of material removal. These parameters include abrasive mesh size, abrasive concentration in media, and the number of passes. A review of published technical articles on the AFM process is attempted in this article, and the studies are divided into four categories: experimental setups, abrasive media, modelling and optimisation, and applications of the AFM process. The review article provides fresh directions for future investigation. Page layout

Machinability and mechanism of abrasive flow machining ultra-precision surface with orientated grinding marks

The loud noise in electric automobile caused by the overlap between orientated grinding marks with meshing line on ground gear tooth surface becomes a big problem for both drivers and manufacturers. Relying on the excellent self-deformation features and trace material removal, the abrasive flow machining (AFM) process exhibited potential machinability for above ultra-precision ground surface. Benefiting by the pseudo network structure, the abrasive media would possess both excellent elasticity and fluid capability, which could be quantitatively reflected by storage modulus, loss modulus and shear thinning nature in rheological properties. Meanwhile, deriving from the CFD simulation, the media exhibited the steady flow velocity and shear stress at the finishing channel, potentially contributing to the finishing uniformity on the target ground channel, which was subsequently confirmed by the change of ground surface morphology and profiles at the initial and finished state. Most convex peaks and concave valleys have been effectively subdued and whittled, leading to a rather smoother surfaces than initial ones. Besides, on account of the different collision position between grains with convex peaks, the finishing mechanism on ground surfaces with orientated marks could be elaborated as the transition effect from directly fractured material removal on convex peak cusp into plastic deformation on residual convex peaks. Combining with the interaction between continuous matrix and discrete grains in flow field, the mechanics on single grain was systematically investigated to establish the material removal theoretical model. Generally, the AFM technique exhibited the stunning machinability on ultra-precision ground surface.

On Characterization of Shear Viscosity and Wall Slip for Concentrated Suspension Flows in Abrasive Flow Machining.

In the realm of abrasive flow machining (AFM), precise finishing and maintaining dimensional accuracy have remained challenging due to non-uniformities in the AFM process and complexities associated with the abrasive media's shear viscosity and wall slip behavior. By addressing these challenges, this study introduces a comprehensive framework, combining theoretical foundations, measurement techniques, and experimental setups. Utilizing capillary flow, a novel compensation strategy is incorporated within the Mooney method to counter entrance pressure drop effects. This enhanced capillary flow method emerges as a promising alternative to the conventional Cox-Merz empirical rule, enabling precise characterization of wall slip behavior and shear viscosity, particularly at elevated shear rates. The abrasive media exhibit a Navier nonlinear wall slip, as highlighted by the Mooney method. Rigorous verification of the proposed methodologies and models against supplemental experiments showcases a high degree of congruence between predicted and observed results, emphasizing their accuracy and broad application potential in AFM. This research illuminates the intricacies of the abrasive media's behavior, accentuating the need for meticulous characterization, and provides a robust foundation for genuine modeling and predictions in material removal within AFM.

Influence of wall-slip on material removal in abrasive flow machining

Abrasive flow machining (AFM) process, as a widely known technique for finishing internal surfaces of complex parts, can significantly improve the performance and reliability of components in numerous industries. Prediction of material removal rate (MRR) is a vital task in AFM process because it significantly affects the efficiency and cost-effectiveness of the process. In-depth studies about the influence of input parameters on material removal in AFM process, however, are limited. In this paper, the mechanism of material removal was investigated, and a MRR modelling was then established in which viscoelastic extrusion modelling with wall slip conditions was employed in AFM process. A novel fixture with gradient shear flow channel was designed. MRR obtained by simulations and experiment showed a reasonable agreement. Finally, parameters, including abrasive media pressure, velocity and shape geometry of flow channel, were identified as key factors affecting MRR in AFM process. Established computational fluid dynamics (CFD) analysis and MRR modelling can be a powerful tool to determine MRR in future AFM process.

Analysis of thermal additive centrifugal abrasive flow machining process with improved electrode geometry

Thermal additive centrifugal abrasive flow machining (TACAFM) is a recent hybrid of abrasive flow machining to cater for its limitation of low material removal (MR) through spark formation and centrifugal action of centrifugal force generating (CFG) electrode. The geometry of the CFG electrode is a crucial parameter in determining the centrifugal action on media and spark formation. The present investigation proposed a novel triangular-shaped electrode for improving the efficiency of the TACAFM process. The validation of spark and flow parameters with the proposed electrode was analysed using ANSYS FLUENT@. The simulation results were further validated by experimentation and artificial neural network modelling. The effect of supply current, rotational speed of CFG electrode and number of cycles were analysed for MR and on percentage improvement in the surface finish (%ΔRa) on the brass workpiece by the proposed electrode. The experimental results show the average cumulative percentage absolute error obtained for MR is 0.33% and that for %ΔRa is 0.96%. The scanning electron microscopy images justify the machining performance through spark generation. The experimental results are in good confirmation of simulation results and highlight the suitability of the proposed electrode for the TACAFM process.

Finishing nonuniformity for electrical discharge machined closed complicated flow channels by abrasive flow machining

Abrasive flow machining (AFM) is increasingly preferred to finish closed complicated flow channels machined by electrical discharge machining (EDM) owing to its high machining accessibility, surface integrity, and efficiency. The machining accuracy of closed complicated flow channels by AFM is dependent on the uniformity of material removal distribution (named as finishing nonuniformity here), but few studies on the finishing nonuniformity have been done so far. Firstly the finishing nonuniformity for EDM machined complicated flow channel by AFM was modeled and analyzed theoretically. Then three blisk with EDM surface roughness of Ra 1.5 μm, Ra 2.0 μm, and Ra 3.0 μm were finished by AFM to Ra 0.8 μm, and their finishing nonuniformity was compared. Finally, AFM flow simulation was carried out, and the simulation results were compared with that from the experiments. Theoretical results showed that finishing nonuniformity is resulted from the non-uniform flow field of the abrasive medium, and it increases with increasing EDM surface roughness and decreasing AFM surface roughness. This is verified by the AFM experiments and flow simulations. On this basis, the guideline for parameter optimization in the combined EDM + AFM process was discussed.

Wall-slip characteristics of viscoelastic abrasive medium in abrasive flow machining process

Wall-slip characteristics of viscoelastic abrasive medium in abrasive flow machining process

An experimental study on the abrasive flow machining of aluminum alloy (AA 2024)

The drilling and boring of the aluminum alloys tubes have a significant challenge in surface defects and burr phenomena. There is an ever-increasing demand for the surface modification and deburring of these components in the manufacturing industries. Most of the advanced machining processes have technological restrictions to overcome these challenges. This paper proposes abrasive flow machining (AFM) to meet these requirements. To explore the machining performance, experiments were conducted on the internal surface of tubes made of aluminum alloys (AA2024) in the various number of AFM cycles for studying and observing its behavior on the surface roughness (Ra) and material removal (MR) characteristics with an empirical approach. The empirical findings prove that the AFM process is effective and efficient for machining the internal surface of tubes AA2024 because the Ra value has been remarkably reduced from 1.785 to 0.474 µm and the maximum value of MR has been obtained up to the range of 42 mg. Moreover, surface morphology analysis shows that the boring operation has generated a rough surface full of surface defects. In contrast, the AFM process has produced a smooth surface without surface defects, improving the surface integrity of tubes AA2024.

Numerical and Experimental Investigation on the Abrasive Flow Machining of Artificial Knee Joint Surface

The titanium alloy artificial knee joint is used extensively in the current medical industry due to its distinct characteristics and properties that are like the real human knee joint, but it does need to be polished to improve its performance and service life before it can be used. Due to the complicated surface profile, the traditional abrasive flow machining technique cannot achieve a good surface finish offering uniformity and quality. Thus, in this paper, a proper constrained flow channel is designed to conduct the abrasive flow machining of the titanium alloy artificial knee joint surface to overcome these issues. A numerical study is first conducted to explore the distribution of abrasive flow velocity and pressure near the target surface in the constrained flow channel by using the COMSOL Multiphysics software, and it is found from the distribution of the dimensionless material removal rate on the target surface that the exchange of the abrasive flow inlet and outlet during the machining process is recommended to improve the surface finish uniformity. Then, the corresponding experiments are conducted to analyze the surface morphology before and after the abrasive flow machining process. It is found that the surface roughness of the target surface decreases from approximately 394 nm to 171 nm with good uniformity as well. Therefore, the proposed abrasive flow machining method with a properly designed constrained flow channel is useful for the rough polishing and fine finishing of the titanium alloy artificial joint.

Optimization and experimental investigation on AA6082/WC metal matrix composites by abrasive flow machining process

Optimization and experimental investigation on AA6082/WC metal matrix composites by abrasive flow machining process

Effect of processing condition on abrasive flow machining process: A review

Abrasive flow machining (AFM) is an advanced manufacturing process. However, the efficiency of this process in terms of material removal rate and surface finish is depends upon the selection of key parameters. Hence the aim of this review paper is to give basic information regarding principle of AFM, classifications (one way, two way, multi-way and orbital AFM), and effects of processing parameters (machine/workpiece/media based parameters) on the performance of AFM. Further, various application area (aerospace, automotive, die and mold, medical, manufacturing industries etc.) of AFM are discussed. Hence, this manuscript will become useful for the futuristic researchers working in the field of AFM.

Modelling of Material Removal in Unidirectional Abrasive Flow Machining process using Classical Indentation Model

Modelling of Material Removal in Unidirectional Abrasive Flow Machining process using Classical Indentation Model

Experimental investigation on the effet of input paramètres on surface roughness and MRR of abrasive flow machining process

A crucial and costly step in the whole manufacturing process is the precision and super finishing procedure. A step of final finishing is involved in the production of precision components. It accounts for a respectable portion of the cost of production overall, is mostly uncontrolled, and requires a lot of manpower. Abrasive finish methods are being developed to address issues including high direct costs and the production of precision components with particular characteristics for finishing inaccessible places. A vast number of cutting blades with arbitrary orientation and shape are used in the abrasive finishing process. Due to their ability to complete a variety of form geometries with the appropriate dimensional accuracy and surface polish, abrasive fine procedures are often used. The unconventional finishing method known as AFM (abrasive flow machining) presses abrasive viscoelastic polymer on the surface of work piece. Al7075/SiC NMMCs’ internal rounded and hollow surfaces are completed using an AFM trial procedure that is constructed and designed in conjunction with specially produced medium. Workpieces are created using a lathe shortly after stir casting metal matrix nano composites with cross sections of 25 mm in diameter and containing 1 percent,1 ,2,3,4 nano-Sic (50 nm) by weight. Extrusion pressure abrasive particle grain size number of cycles were evaluated for their surface roughness (Ra) than material removal (MR), respectively. The evaluation of the material’s qualities, such as density, hardness, and tensile strength The improvement in the surface completeness of these NMMCs is further shown by the scanning Microscopy OM, EDS SEM, and XED analyses.

Modelling of material removal in unidirectional abrasive flow machining process using classical indentation model

Modelling of material removal in unidirectional abrasive flow machining process using classical indentation model

Internal Surface Roughness Measurement of Metal AM Channels via X-ray Computed Tomography: A Case Study

Additive manufacturing (AM) is able to create engineering components with internal features that are unmeasurable using conventional tactile and optical methods; new methods for measuring internal inaccessible features in a non-destructive manner are required. In this work a metal additively manufactured (AM) component with an internal channel is fabricated and scanned via X-ray computed tomography (XCT) before and after undergoing internal surface polishing by means of abrasive flow machining (AFM). The internal surface roughness of the AM channel is characterised in 3D to better understand and control the AFM process. The results show that XCT is able to reveal the complex internal surface texture of metal AM components and to quantify the changes caused by the AFM process.

Experimental investigations into ultrasonic assisted magnetic abrasive flow machining process

ABSTRACT In the present study, an advanced variant of abrasive flow machining (AFM) is developed. Ultrasonic assistance and magnetic field assistance with rotating effect have been designed, fabricated, and simultaneously used to develop ultrasonic-assisted magnetic abrasive flow machining (UAMAFM) process. The ultrasonic horn and electromagnets were designed based on the simu modified by adding iron particles to make abrasive media respond effectively under the applied magnetic field. The effects of the external assistances, machine, and media-based parameters were explored on the amount of material removed (MR) and percentage improvement in the surface roughness (% ΔRa) for pure titanium (Grade II). The influence of input parameters was investigated using analysis of variance (ANOVA) by analyzing the process responses. Quadratic regression models showing the effect of input parameters and their interaction were developed for each response. The influence of individual parameters on process outcomes and response surface plots for significant interactions have also been discussed. The maximum MR of 26.62 mg and ΔRa of 54.42% were achieved at the optimized setting of process parameters. The predicted values of MR and % ΔRa from developed statistical models agreed with the experimental results.

Modeling and quantitative study of soft contact between abrasive medium and active abrasive particles in abrasive flow machining

In abrasive flow machining (AFM), material is abraded by active abrasive particles powered by solid-liquid contact between them and the abrasive medium. This contact characteristic is a key and unfortunately it is investigated scarcely.In this work, a soft-contact model was firstly proposed. Soft-contact parameters including protrusion ratio and covering inclination angle were then defined to characterize soft-contact characteristics. Finally, the effect of medium pressure and particle diameter on soft-contact parameters was studied by full factorial design. Results showed that average scratch depth of single active abrasive particle increases with increasing particle diameter and medium pressure. In addition, active abrasive particles are actually deeply wrapped to a large proportion by abrasive medium, and the descriptive protrusion ratio decreases with increasing medium pressure and particle diameter. Moreover, medium pressure offers tangential and normal force for active abrasive particle through a covering inclination angle, and the angle increases with increasing medium pressure and particle diameter. It provides guidance for further improvement of prediction accuracy of material removal in AFM process.

Flow rate improvements in additively manufactured flow channels suitable for rocket engine application

This contribution describes the investigation of flow channels which are designed to be directly integrated into an aerospike engine by means of additive manufacturing with laser powder bed fusion (LPBF). During the experimental testing of a previous aerospike engine in 2019, it was observed that high surface roughness of such additively manufactured integrated channels caused a significant reduction in the mass flow rates of the propellants ethanol and liquid oxygen as well as the coolant due to increased pressure drop. In an extensive study within the CFDmikroSAT project, various factors influencing this surface roughness are, therefore, being investigated, which include the geometry of the channels as well as selected manufacturing parameters of the LPBF process, such as layer thickness and component orientation. To further reduce the roughness after manufacturing, suitable post-processing methods are also being investigated for internal cavities, initially analysing the abrasive flow machining process. Within the paper, the overall investigation approach is presented, such as the overview of the considered specimens, and the initial results of a various studies with selected specimens are discussed. These studies consist of the examination of surface roughness reduction, shape accuracy and flow behaviour of post-processed cooling channel specimens. Finally, a brief overview of the already manufactured aerospike demonstrator is presented.