Internal Finishing of Aluminium Tube with Sintered Magnetic Abrasive

Narinder Singh, Hemant Kumar, Jagdeep Singh Gill

There has been a rapid growth in the development of harder and complex shapes to machine metals and alloys during the last few years. Conventional edged tool machining is difficult and uneconomical for such materials and degree of surface finish attainable is poor. In view of the seriousness of this problem, recently new non-conventional fine machining processes like Magnetic Abrasive Polishing, Magnetic Abrasive Flow Machining (MAFM), Magnetic Float Machining (MFM) and Magnetic Abrasive Machining (MAM), Magneto –Rheological Machining (MRM), Chemo-Mechanical Polishing (CMP) have been developed. Among these processes ‘Magnetic Abrasive Finishing processes are widely used for obtaining quality finish on metallic (ferrous and non ferrous) as well as non metallic (ceramics) components. MAF process has been recently used in its variant forms such as Magnetic float polishing, Magneto-rheological machining, Electrolytic magnetic polishing but the problem of development of magnetic abrasive powders is still present and efforts are in continuous progress at global to remove this problem. In the MAF method, a magnetic field is used to generate cutting force to treat the surface of a machined part. The magnetic field helps to form a flexible magnetic abrasives brush for finishing of surface.  Finishing force can be controlled with magnetic field and a low surface temperature is generated during finishing operations. Magnetic abrasives are not easily available. Very few studies have been reported till date on the development of alternative magnetic abrasives. The aim of study is to evaluate the performance of developed sintered magnetic abrasives for internal finishing of aluminium tubes using MAF process. PISF is calculated  considering different variables like speed (rpm) , quantity of abrasive and gap of magnetic pole and work piece.  Preparation of sintered magnetic abrasive was difficult and time consuming. The best result came at 425 rpm and quantity of abrasive used 6 gm. PISF value obtained in present case was 84 % .