Characteristics of the Polishing Effects for the Stainless Tubes in Magnetic Finishing with Gel Abrasive

Abstract

Magnetic abrasive finishing (MAF) is a fast, high efficiency and high-precision polishing method on the surface machining of the metals. Furthermore, MAF also can be utilized to polish the stainless tubes in industrial applications; however, stainless tubes are often a non-magnetic material that makes it difficult for the magnetic field line to penetrate into the stainless tubes, thus reducing the magnetic forces in the inner tubes polishing. That is why stainless tubes are not easy to finish using traditional MAF. Therefore, magnetic finishing with gel abrasive (MFGA) applies gels mixed with steel grit and abrasives that were developed to improve the polishing efficiency and surface uniformity of the steel elements. In this study, a guar gum or silicone gel mixed with steel grit and silicon carbides are used as the magnetic abrasive gel to polish the stainless inner tubes. A DC motor was used to control the rotation speed of the chuck and an AC induction motor connected with an eccentric cam to produce the reciprocating motion of the workpiece were utilized to finish the inner surface of stainless tubes in the polishing process. The parameters of abrasive concentration, abrasive particle sizes, rotation speeds of motor and electric currents were used to investigate the surface roughness and the removal of materials from the stainless tubes. The experimental results showed that since guar gum had better fluidity than the silicone gel did, guar gum created excellent polishing efficiency in MFGA. Furthermore, the surface roughness of the stainless tube decreased from 0.646 μm Ra to below 0.056 μm Ra after processing for 30 min with the parameters of current 3A, gel abrasive with guar gum, rotational speed 1300 rpm and vibration frequency 4 Hz.

Features of mechanical processing of aluminum alloys

“…The surface layer is structurally always heterogeneous. Also, the authors of many studies believe that the reduction of the roughness of the polished surface can be achieved by various methods, the choice or combination of which determines the success in solving the task [19][20][21][22][23]. But, unfortunately, the degree of influence of one or another technological factor on the roughness of the treated surface has not yet been clarified.…”

Study of the Polishing Characteristics by Abrasive Flow Machining with a Rotating Device

“…In this nano-finishing method, the stirrer and the workpiece rotated in opposite directions at the same time during the polishing process and gel abrasive was pushed by the stirrer to abrade the working surface; the interior surfaces of the holes reached ultra-low roughness after R-AF. Moreover, magneto-rheological abrasive flow finishing (MR-AFF) has also been shown to achieve better performance of radial force as compared with traditional AFM [16][17][18]. In MR-AFF, magnetic particles and an electro-magnetic mechanism are applied to increase the abrasive cutting forces in the finishing process, furthermore, steel grits and abrasives are also constrained by the gel, inducing a flexible self-sharpening effect in the finishing process, and therefore, the inner surface can be polished to a very precision level.…”

Study on Mechanism of Roundness Improvement by the Internal Magnetic Abrasive Finishing Process Using Magnetic Machining Tool

“…In addition, the stochastic approach to experimental analysis of the cylindrical lapping process was studied and it was concluded that lapping pressure has a significant effect on the efficiency of cylindrical lapping [13]. Wang et al studied a high-precision polishing method for magnetic gel abrasive finishing and 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 finish the internal surface of the stainless tubes [14,15]. Zou et al developed an internal magnetic abrasive finishing process using a magnetic machining tool to improve the roughness and the roundness of the internal surface of a thick tube [16].…”