Chromium surface treatment of nickel-based substrates

DETAILED DESCRIPTION The present invention provides a method for applying a chromium surface treatment to nickel-based aerospace components to improve the corrosion resistance properties of the components while retaining thermal conductivity in order to efficiently transfer internally generated heat to the exterior of the component during anti-icing or deicing procedures.
The present method includes the steps of: ion plating a nickel-based substrate with chromium atoms using an ion-aided deposition process; thermally treating the chromium-plated nickel-based substrate in a generally inert environment to interdiffuse chromium and nickel atoms at a near surface region of the chromium-plated nickel-based substrate; and thermally treating the chromium-plated nickel-based substrate in an oxygen-containing environment to oxidize the chromium atoms at exposed surfaces and create a layer of chromium oxide.
The thickness or build-up of chromium and chromium oxide is maintained thin enough to fall within a prescribed tolerance for functional operation of the components.
The method for applying a chromium surface treatment to nickel-based substrates can be used to satisfy the need for air data sensors or probes that exhibit improved corrosion resistance compared to conventional nickel sensors or probes and retain thermal conductivity in order to readily transfer heat from internally placed heater coils to the exterior surfaces of the air data sensor or probe.