Papers by Author: Prabhu Shankar Misra

Abstract: Wear study of metal matrix composites used as friction material is one of the most important parameter for determining the brake performance. The present investigations relates to the development of Aluminum powder based brake pads; where the back plates are also made of Aluminum based powders respectively. Thus it is aimed to fabricate net-shape Aluminium powder based brake pads in a single forming operation with better characteristics (low wear, low temperature rise, stable coefficient of friction) employing a newly developed technology namely “Hot Powder Preform Forging” technique. Three Aluminum based friction composites which are designated as ALM 01, ALM 02 & ALM 03 were formulated. The dry wear test is carried out using a pin-on-disc tribo-tester at constant sliding speed of 9 ms-1 under a load of 50 N. The counter face disc is made of heat treated grey cast iron. During the test, the cumulative wear (gm), Coefficient of friction, temperature rise (oC) and noise level (dB) were recorded. The effect of load at constant speed on sliding wear, frictional characteristic of aluminum based MMC (rotor / drum) in dry condition is studied. On the basis of initial laboratory tests like density, Hardness, wear test, the samples were qualified for sub-scale dynamometer test at Rejected Take Off condition. Optical microscope was used to investigate the microstructure of metal matrix friction composites surfaces. The results revealed that coefficient of friction was more stable. The Cumulative wear (gm) was low with rise in temperature. It was also observed that distribution of ingredients in matrix was fine and homogeneous.

Abstract: Abstract: The magnetic abrasive finishing (MAF) process which was introduced during the late 1940s has emerged as an important non-traditional metal finishing process. The process has found applications in a wide range of fields such as aerospace, medical, electronics, precision dies and moulds as a part of their manufacturing activities. Magnetic abrasive grit size, magnetic field intensity, magnet & workpiece gap, relative speed between workpiece & magnet, vibration of workpiece/magnet are the principal parameters that control the surface characteristics. MAF is the process that is being developed for efficient & precision finishing upto nanolevel of cylindrical or flat workpieces made of hard to machine materials. This review provides an insight into the fundamental parameters and creates a better understanding of this finishing process, with the objective of helping in the selection of optimum machining parameters for finishing of varied workpieces in practice.