Abstract
The sintered iron compacts will be able to be applied to selflubricating porous bearing, filter and metallic mold for casting, etc., because they have useful porosity. However, they do not have oxidation resistance, wear resistance and good mechanical properties. The chemical vapor deposition process (CVD process) is expected to give them good oxidation resistance and wear resistance. In this paper, the properties of the porous sintered iron compacts coated with TiC and Al2O3 by CVD process were investigated. The results obtained are as follows:
The CVD coatings of the porous sintered iron compact are thinner from the surface forward the inside. The TiC coatings are smooth throughout the sintered compact, while the laminated coatings of TiC and Al2O3 are smooth in the surface part and granular toward the inside. The granular products on coatings are Al2O3. The hardness and the transverse rupture strength of the porous sintered iron compacts are remarkably increased and the intercommunicating porosity is decreased by the CVD treatment. The oxidation resistance is improved when the laminated coating of TiC and Al2O3 is repeated more than twice. The transverse rupture strength is not decreased and the intercommunicating porosity is decreased by oxidation.
