| Abstract: |
Solid-particle erosion of metals and alloys at elevated temperatures is one of the main reasons of the damage of components used in the energy production and utilization industries. Apart from the selection of relevant erosion-resistant bulk materials, a development of protecting coating systems can be an attractive and economically reasonable solution for preventing the failure and increasing the durability of the components working in severe conditions of high-temperature corrosion and erosion. Thermal spraying which offers a variety of deposition methods is a flexible technology that enables the application of a wide range of metal, ceramic and composite materials. Nevertheless, thermal spraying of intermetallic materials, which possesses excellent high-temperature corrosion resistance, is limited because of their low ductility. The aim of the present work is the investigation of abrasion wear resistance at elevated temperatures of combined coatings, which include the intermetallic layer. Such iron aluminide layers have been formed due to the diffusion during the heat post-treatment of arc-prayed metallic coatings combining Fe- and Al-based layers. Post-treatment of arc-sprayed coatings was carried out by means of infrared radiation and induction heating. It was shown that the abrasion resistance of the developed coating tested at elevated temperatures (T > 500 °C) is considerably higher than that of low-alloyed steel and some nickel-based alloys and depends on the test load condition. At the low rate of abrasive particles flow, the protecting effect of intermetallic layer is defined mostly by microhardness of the reacted phases. By increasing the load impact, the wear of coating depends on the microstructure of the coating, especially its porosity and the presence of micro- and macro-cracks. It has been shown that the high performance of intermetallic-based graded coatings at elevated temperatures make them interesting for applications as a low-cost erosion-corrosion-resistant material.
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