Influence of silicide coatings on the mechanical properties of the NT-50 alloy

We have investigated the effect of silicide coatings on the ultimate strength of NT-50 alloy over the temperature range −196...+1100 °C. From 196 to 800 °C the ultimate strength of silicidated specimens was lower than that of the initial and annealed alloy whereas from 900 °C it was slightly higher. We have also examined the effect of silicide coatings on the relative elongation of NT-50 alloy samples. Over the temperature range −196...+1100 °C, the relative elongation of specimens annealed in a vacuum of 6.7 · 10−3 Pa at 1250 °C for 4 h was found to be lower than that of the silicidated specimens. This is attributed to the dissolution of the residual gases (O2, N2, H2, CO, and CO2) under vacuum annealing.