Machinability of bimetallic bearings using cemented carbide tools: evaluation of the wear mechanisms

This text presents informations regarding the complexity of simultaneously machining two distinct materials: GH190 gray cast iron and Fe-C-Cu steel alloy, being the latter obtained through powder metallurgy. The machining of the bearings in the cylindrical boring process using cemented carbide tools coated with titanium nitride (TiN) has also been evaluated. The feed rate has been varied while the other parameters, such as cutting speed and depth of cut, were kept fixed. After the flank wear on the tools was monitored it was possible to conclude that for a certain number of workpieces machined, the wear process on the tools was less severe when the feed rate was increased. The worn surfaces were analyzed with an electronic microscope. High levels of adherence have been observed and the main wearing mechanisms were adhesion, diffusion and attrition. (C) 2004 Elsevier B.V. All rights reserved.