Wide Temperature Range Tribological Property of Inconel 718 High-Temperature Alloy

In order to investigate wide temperature range tribological property of Inconel 718 high-temperature alloy before and after high temperature oxidation, Inconel 718 high-temperature alloys were treated at 1 000 ℃ in air. Scanning electron microscopy and 3D surface mapping profiler were conduct to analyze the surface morphologies and worn surface morphologies of Inconel 718 high-temperature alloy. The X-Ray Diffraction was used to analyze the composition and structure of Inconel 718 high-temperature alloy. The results show that the degree of crystallization of Inconel 718 high-temperature alloy was improved after treating at 1 000 ℃, and a mesh-like heave structure formed on surface of treatled Inconel 718 high-temperature alloy which was composed of Cr₂Ti₇O₁₇ and Cr₂O₃. During treating process, Cr and Ti atoms diffused upward along the grain boundaries, and reacted with oxygen to form Cr₂Ti₇O₁₇ and Cr₂O₃. Compared with untreated sample, the coefficient of friction and wear rate of treated one were improved obviously, which was ascribed to the mesh-like heave structure.