Environment-frendly Electromagnetic Wave Absorber Using Bearing Grinding Sludge

Abstract

At a bearing manufacturing plant, a large quantity of grinding sludge is discharged from finish machining process. The microstructure of this sludge is a fiber form which entangles naturally. Raw sludge is not an electromagnetic wave absorber because of its conductivity. The sludge was therefore ground into minute particles by a mechanical alloying method (MA). An electromagnetic wave absorber was then produced using MA-treated bearing grinding sludge for magnetic loss factor. These electromagnetic wave absorbers had practical efficiency at Blue Tooth frequency (2.45 GHz) and ETC frequency (5.8 GHz).