Improvement of Resistance of Structural Metal Ceramics of Fe-C-Mn-Mo- Cr Type by Boron Nonmetalic Coatings

Improvement of Resistance of Structural Metal Ceramics of Fe-C-Mn-MoCr Type by Boron Nonmetalic Coatings I. Mitev Department of Machinery and Equipment Technical University of Gabrovo 4, H. Dimiter str. Bulgaria ______________________________________________________________________________________ Abstract: During the last years the development of powder metallurgy is connected with constant search and elaboration of new materials to improve mechanical properties of workpieces. Such type of materials are structural powder materials of the system Fe-C-Mn-Mo-Cr, which are elaborated on the basis of “Astaloy” powders. The elaboration work studies the wear resistance of this type of materials in the process of priction after chemical and thermal treatment with boron nonmetal coatings (B-C, B-Si) during 2, 3 and 4 hours at 950°C. It presents graphic relations that show the changes of microhardness along the cross-section of the models tested as well as such ones that show their resistance in the process of dry friction depending on their density and the type of their chemical and thermal coating.