The Effect of Rhodium Addition on Degradation Behavior of Ir-10 mass％Rh Alloy during Oxidation at Elevated Temperatures

This paper focuses on effect of rhodium addition degradation behavior Ir-10 mass％Rh alloy for a spark plug during oxidation at elevated temperatures. Oxidation tests were conducted the temperature range from 1173 K to 1473 in Ar-21％O2 gas mixture clarify alloy. As result, there are three effects prevent degradation: (1) dissolution into iridium oxide scale below 1273 K, which decreases activity scale, (2) above and (3) formation oxide, surface area All contribute decrease vapor pressure volatile resulting suppression degradation.