Papers by Keyword: Abrasive Flow Machining

Abstract: Since abrasive gels with single direction motion are very difficulty to achieve the smooth surfaces in the complex holes finishing during abrasive flow machining (AFM), therefore, the helical cores were proposed here to create the multiple motions of abrasive gels to get the even surface of the complex holes in AFM. The results showed that helical core with 5 spiral grooves and narrow gap between the core tip and the hole could obtain the even surface and fine surface roughness after AMF.

Abstract: Abrasive flow machining (AFM) is one of the most promising technologies for internal finishing and de-burring for features with complex geometry. This study investigates the effect of media degradation on finishing characteristics achieved using the AFM process. A total of 50 experiments, using Inconel 718 cylindrical coupons machined by Wire-Electron Discharge Machining (WEDM), were conducted employing the same process conditions while using a single batch of AFM media. Experimental results indicate that media degradation has minor influence on surface roughness, but more significant influence on material removal and media flow rate. Material removal decreases exponentially with increasing cumulative media flow volume despite media flow rate increasing. There is a linear correlation between material removal and media flow rate. As a result, material removal can be estimated from media flow rate which can be monitored easily.

Abstract: Abrasive flow machining is a suitable technique for surface polishing due to its rheological characteristics, however, it's difficult to achieve uniform roughness for polished surfaces as the material removal mechanism is still ambiguous. In this paper the viscoelastic properties of abrasive flow media are incorporated to explore the phenomena of inconsistent material removal in the AFM polishing process, where the material removal near the edges is obviously higher than that in the middle along the flow direction. The rheological parameters of the viscoelastic constitutive model adopted are varied to study the polishing effectiveness under different process conditions. The results of numerical analysis reveal that there exist distinct differences of viscoelastic stress fields between the edges and the middle regions, which leads to the material removal near the edges is higher than that in the middle. It could be concluded that the viscoelastic properties of abrasive media play the dominant role for the inconsistent material removal in abrasive flow machining process.

Abstract: The wear performance of the mild steel under different Abrasive Flow Machining (AFM) conditions was studied. Wear properties of mild steel are considerably affected by the process parameters of AFM.The effect of extrusion pressure, abrasive concentration and abrasive size during AFM on wear performance were investigated using a reciprocating wear testing machine. Experiments were conducted according to 2³ factorial design of experiments for this purpose. The contribution of the process parameters on wear resistance were obtained performing Analysis of Variance (ANOVA). The wear rate, specific wear coefficient (Ks), wear resistance, fatigue strength and surface hardness are also considerably affected by the process parameters abrasive concentration, extrusion pressure and abrasive size.

Abstract: Based on the solid - liquid two-coupling theory, Use abrasive medium viscosity-temperature characteristics related to the mathematical model, using solid - liquid two-phase solution method Mixture models and standards, turbulence model combining with common rail pipe hole as the research object, choose different initial temperatures and processing procedures, numerical analysis was carried out on the flow channel wall temperature and turbulent kinetic energy. Using numerical analysis software FLUENT Abrasive Flow Machining rail tube orifice structure was three-dimensional numerical analysis; obtain a steady-state pressure, dynamic pressure, velocity, turbulent kinetic energy image, to study Abrasive Flow Machining process provides a theoretical basis and technical support.

Abstract: In this paper, a control system based on the prediction of processing flow in Abrasive flow machining is designed. In this system,flow is predicted by an improved GM(1,1) model in conformation of background value. Combined with fuzzy control system, it can adapt the pressure to meet the processing requirement automatically. Experiments proved that the improved GM(1,1) model can predict the processing flow accuratly, and the fuzzy control system based on grey prediction can improve the machining accuracy of micro-hole AFM effectively.

Abstract: This paper deals with the improving lay of finish and the superfinishing of the nozzles which is used in plasma cutting operation. This is basically alternative solution to present finish obtained by turning, drilling and reaming of the profiled bores and orifices. The advance micromachining process were developed, known as Abrasive Flow Machining (AFM) which is capable to altering the orifice (nozzle of plasma cutting machines) so that present process is to be improved without altering the geometry of the component. The effects of different process parameters such as number of cycles, concentration of abrasive, abrasive mesh size and media flow speed, surface finish are studied here. The design of the experiments 16(2⁴) provides two levels for each variable. These levels are taken into consideration for finding out the effect of variation of parameters on the surface roughness of the copper orifice. The objective of paper is to learn how each parameter is considered for Abrasive Flow Machining such as: abrasive concentration in media, number of cycles, abrasive mesh size and media flow speed affects the surface roughness of copper orifice also to find out the mathematical relationship between surface roughness value and process parameters. Analysis of Variance (ANOVA) for the experimental data has been carried out and optimizations of abrasive flow machining process parameters were done. Also Analytic Hierarchy Process (AHP) done here for selecting hierarchy process parameter .Capabilities of the machine ultimately improved with the new technology developed.

Abstract: Surface finish and Manufacturing process has a prominent role in the fatigue life of a machine component. Fatigue strength of a material generally increases with the surface finish. But the super finishing process like electro polishing reduces the fatigue strength of the material. In Abrasive flow machining it is found that surface finish and fatigue strength always increasing. In Abrasive flow machining the fatigue strength is mainly governed by the process variables extrusion pressure, abrasive concentration and mesh size. This research studies the influence of the process variables on the fatigue strength of the material. In this study an approximate surface finish of 4μm is obtained after AFM. The effect of three process variables on the response function selected, fatigue strength, were studied. A statistical 2³ full factorial experimental technique is used to find out the main effect, interaction effect and contribution of each variable on fatigue strength. The instron machine is used to find out the number of cycles to failure of the material. The fatigue strength is obtained with S-N curve analysis.

Abstract: Common-rail pipe is an important component of fuel injection system, whose inner cavity is hidden and requires a high precision. So that the general mechanical processing is difficult to achieve, while abrasive flow machining just be able to solve this problem. In this article, the three-dimensional model of common-rail pipe is established and meshed by GAMBIT, next the mesh file is read into FLUENT, and then the Mixture model is used for numerical simulation. By analyzing the simulation results, we can get how will the pressure difference between inlet and outlet, the volume fraction of abrasive, and the processing order impact on the processing quality. Finally, a reasonable processing program is proposed for the common-rail pipe.

Abstract: Abrasive medium plays an important role in the application of abrasive flow machining (AFM), a process that finishes complex internal and external geometries. A new abrasive medium needs to be fabricated due to a lack of literature on it. In this work, a new abrasive medium was fabricated by using styrene butadiene rubber (SBR) as carrier and DF-101S was used to study its characterization. Results showed that new abrasive medium with good fluidity and temperature stability was obtained. Processing experiments have also been carried out by using new abrasive medium and MLLD60, and ZYGO was used to study the surface characteristics of the work-piece. Experimental results indicate that the new abrasive medium is applicable to AFM process.