Жаростойкость медно-никелевых сплавов, синтезированных искровым плазменным спеканием

Abstract

The article presents data on heat resistance high-temperature tests of powder materials based on copper-nickel have been carried out. The oxidation features of materials samples with various alloying elements have been studied. Compaction of copper-nickel alloys samples was done by spark plasma sintering (SPS). The dependence of the growth rate of the oxide film on the temperature of high-temperature oxidation was established, and the effect of alloying elements in the composition of the samples on their heat resistance was considered. Based on the study’s results the dependence of the oxide film growth rate on high-temperature oxidation and the influence of alloying elements in the composition of sintered copper-nickel alloys on their heat resistance are considered. It was determined that for all the considered samples compositions of copper-nickel alloys synthesized by spark plasma sintering, the temperature 1000 °C of 20-hour heating heat resistance test is not the limiting one, since the samples retain their integrity. It is shown that simultaneous alloying of copper-nickel alloys with aluminum and chromium provides the highest heat resistance. The scale growth rate for composition Cu – Ni – Cr – Al 1.49·10–3 g/cm3 is lower than the oxidation rate of pure nickel 3.78·10–3 g/cm3 at 1000 °C. These two samples demonstrate the lowest weight gain after testing at 1000 °С, for compositions Cu – Ni – Al, Cu – Ni – Cr – Si and 50 wt. % Cu – 50 wt. % Ni the oxidation rate increases by two orders of magnitude, for compositions Cu – Ni – Si and Ni — by three orders of magnitude.