Experimental analysis of surface finishing properties in Magnetically Assisted Abrasive Finishing of ASTM B16 Brass

Magnetically assisted abrasive finishing (MAAF) presents an attractive concept of surface and edge finishing by fine magnetic abrasive particles (MAPs). This study aims to contribute an experimental evaluation of the effect of process parameters viz. magnetic field density (MFD), circumferential speed of workpiece, and abrasive grit size on the surface finishing properties in MAAF when experiments were performed for finishing pipes of ASTM B16 brass material with the sintered MAPs. The developed model is based on the obtained experimental data accompanied by “Box- Behnken design (BBD) of response surface methodology (RSM)” analysis. Apart from deciding significant parameters, this analysis also presents the modeling of finishing properties and optimizes the desired performance parameters. Analysis of variance (ANOVA) includes data of standard deviation, coefficient of determination (R2), adjusted, and predicted (R2). MFD and speed show a significant effect on both the responses viz. “surface roughness improvement rate (SRIR) and material removal rate (MRR)”. Analysis has shown that abrasive grit size is the most dominant parameter towards SRIR followed by MFD. The maximum SRIR of 88.12% (minimum Ra 50 nm) and 4.28 mg/min is achieved through multi-objective optimization with 0.8 T MFD, 500 rpm speed, and 300 µm grit size. The mathematical models of SRIR and MRR were also developed using RSM, focusing on varying MFD, speed, and grit size which can be used to predict the desired surface finishing properties. The model generated for SRIR, and MRR has an error of 0.204 % and 2.506 % respectively. Further SEM images were taken to understand the surface appearance of the finished surface.

Magnetic-abrasive finishing with new diffusion-alloyed materials based on dispersed metal waste

The article discusses the issues of assessing the effectiveness of the use of new diffusion-alloyed ferromagnetic abrasive materials in the technology of magnetic abrasive finishing. The productivity of processing and the roughness of the processed surface were evaluated as they are considered to be the main performance criteria of ferric-abrasive powders (FAP). There were researched three types of powders: common Fe-TiC powder, obtained by the sintering (as a reference), and two new diffusion alloyed (borated and nitrocarburized) FAP, made of low-carbon finely dispersed ferrum-based wastes. Both new proposed diffusion-alloyed powders have better cutting characteristics then reference powder, explained by the structure features and their properties. Evaluation of productivity and roughness of surface shows, that there is their direct dependence of morphology, hardness and fragility of powder particles. The best cutting characteristics has borated powders, as they have microhardness 18,000-20,000 MPa and the tendency to brittle fracture, that leads to the new less-sized particles with sharp cutting edges creation.

Modelling Of Wind Turbine Magnet for Magnetic Abrasive Finishing and Magnetic Field Assisted Abrasive Flow Machining Process

Magnetic Abrasive Finishing is a significant process for finishing up to the micro-level. However, with the advancement of technology and hybrids like Viscoelastic magnetic abrasive Finishing and Magnetic abrasive Flow machining, it has become a nano finishing process. To improve the finishing process, the researchers have made a Model and tested the feasibility of the wind turbine magnet in Finishing. The Maxwell simulations were done for the cylindrical Specimen of Brass, Steel Aluminum. The simulations results were in accordance with the fact that the proposed wind turbine magnet may be used for the simulations.

Influence of Process Parameters and Initial Surface on Magnetic Abrasive Finishing of Flat Surfaces on CNC Machine Tools

Magnetic abrasive finishing (MAF) shows a high potential for use on computerized numerical control (CNC) machine tools as a standard tool to polish workpieces directly after the milling process. This paper presents a new MAF tool with a single, large permanent magnet and a novel top cover structure for finishing the plain ferromagnetic workpieces. The top cover structure of the MAF tool, combined with an optimized working gap, ensures the effect of mechanical powder compaction, which leads to a significant increase in process capability and surface roughness reduction. The influence of the process parameters such as feed rate, equivalent cutting speed, working gap (including for three grain sizes) and the gap to the magnet was investigated. In addition, the influence of the initial surface after face milling, end milling, ball end milling and grinding on the surface quality after MAF was investigated. Furthermore, three typical surfaces after milling and MAF were analyzed. By magnetic abrasive finishing, a significant surface quality improvement of the initial milled surfaces to roughness values up to Ra = 0.02 µm and Rz = 0.12 µm in one processing step could be achieved.

Study on the Polishing Characteristics of the Rotating Cylinder-Based Magnetic Gel Abrasive Finishing

Magnetic gel abrasive finishing is a high-precision polishing method that uses magnetic forces to attract and restrain a gel abrasive, composed of aqueous slime gel, steel grits, and silicon carbon (SiC), for polishing workpieces. However, the magnetic adsorption performance of the gel abrasive will drop quickly when polishing non-ferromagnetic material such as stainless-steel or brass. Moreover, centrifugal force will push out the gel abrasive from the machining surface reducing the stability of polishing. Therefore, this paper developed a rotating cylinder-based magnetic finishing setup to allow the gel abrasive and workpieces to tumble and rotate together during the polishing process. To make the gel abrasive produce irregular and complicated movement paths for improving the polishing performance, this study first analyzed and compared the average surface roughness and removed material weight of workpieces using three kinds of motor operating modes; a unidirectional trapezoidal wave mode, a bidirectional sine wave mode, and a bidirectional trapezoidal wave mode. After identifying the best motor operating mode, the study further compared the polishing characteristics using several SiC particle and steel grit sizes. The experimental results showed that the rotating cylinder driven using a bidirectional trapezoidal wave could obtain better results for average surface roughness and removed material weight than the other two operating modes, while use of the larger steel grit size also obtained improved results. However, different silicon carbide particle sizes did not have a significant impact on the polishing characteristics.