Effect of Low Temperature Heat Treatment for R512E Coated C-103 Nb Alloy

Abstract

The article aims to investigate the feasibility of oxidation protection imparted to C-103 Nb-based alloy by fused slurry silicide coating of R512E (60Si20Fe20Cr) carried out at lower temperature (1200 °C) for higher dwell time i.e. 12 hours. The findings reveal that the coating treated can impart sufficient oxidation resistance the alloy, which may withstand the desired application conditions wherein oxidation protection for smaller time period is needed. Moreover, this treatment is not found to deteriorate other mechanical properties of the alloy in 'As coated' condition.

Oxidation Resistant Nickel Aluminide Coating on Niobium Alloy C103 for High Temperature Aerospace Applications

“…They oxidize easily above 250 o C with oxidation rate rising sharply above 500 o C and tend to form loose oxide scales leading to severe dimensional degradation at higher temperatures. [3]. For this purpose, development of oxidation resistant NiAl coating was carried out which proved out to be safe until 1234 o C.Aluminium in NiAl played a vital role by developing a protective alumina scale (Al2O3) by reacting with oxygen from atmosphere.…”

“…Besides moderate mechanical properties, high melting point and superior thermal conductivity; Niobium alloys till date never successfully defeated the limitation of their catastrophic oxidation at high temperature. For all practical purposes, there are no elevated temperature applications (above 250 o C) outside a controlled atmosphere for Niobium alloys without the use of oxidation protective coatings [3]. In order to cater this issue, variety of aluminides and silicides were employed as oxidation protective coatings, which are reported to improve the oxidation resistance of treated parts and prolong the lifetime.…”