Fabrication of WC/Fe composite coating by centrifugal casting plus in-situ synthesis techniques

摘要

Using tungsten wires as a reactive source, an iron-based composite coating, reinforced by tungsten carbide (WC) particles, with a thickness of 3.0 mm, was fabricated on the surface of a gray cast iron substrate by centrifugal casting plus in-situ synthesis techniques. With the help of differential thermal analysis (DTA), an appropriate pouring temperature of the gray cast iron molten was determined to be 1300 °C. The experimental results show that the composite coating is dense and consists mainly of primary WC carbides, fine secondly WC carbides as the reinforcing phases and pearlite accompanied by negligible graphite flakes as the matrix. Wear resistance of the composite coating was determined with a pin-on-disc wear test technique, indicating that the composite coating, containing high volume fraction of hard WC carbides, present good wear resistance property compared with the un-reinforced gray cast iron, regardless of load level. Additionally, according to the Fe-W-C ternary phase, reaction paths between tungsten wires and molten, and in-situ synthesis of WC particles, were investigated.