Study and characterization of the alloy WC-Co-Cr deposited by HVOF

Abstract

A major industrial impact problem is the operational wear of metallic devices that directly involve the replacement of a part and, therefore, a new investment. To increase the operating life of a device that is under wear, it is possible to apply a coating on its surface that has more robust properties, thus allowing to utilize a substrate material with a lower cost, bringing to the industrial system cost benefit according to the operating life. However, for agricultural machines production, the use of coating is still little used, as compared with other industry segments, as compared with other industry segments. The northwest region of the State of Rio Grande do Sul, Brazil, is a very important mechanical industry pole of the agricultural machines, that justify this study considering the chance of growth the use of the coatings.The operating atmosphere of the device determines the coating selection, especially on this case, the selection occurred together with the partner company of this research, Rijeza Metalworking. It was chosen to work with thermal spray, applying the HVOF process and with the WC-Co-Cr alloy. The selected surface treatment closely of the coating should bring about a marked improvement in abrasive wear.A series of tests were quest for search of results that prove or not these properties to evaluate the performance of the prepared sample. The tests performed to know the characteristics of the sample consisted of wear pin-on-disc; the subsequent analyses were friction coefficient, microhardness, microstructure, scanning electron microscopy, dispersive energy spectroscopy and roughness.The material was weighed, before and after the abrasive wear test; this in turn did not show a statistically significant variation. The parameters that were tested and compared with the data provided by the partner company were all consistent with each other, with low discrepancy.