Codeposition of Metals for Oxidation Protection Above 2200 Degrees Centigrade

铂族金属（PGM）涂层已经显示出提供 2200 ℃以下火箭发动机部件的氧化防护 C. 铂、铑和铱与锆形成化合物， 铪。 这些化合物非常令人感兴趣，因为它们非常 稳定，熔点高于任何一种成分。 此外，锆和铪可以通过化学气相形成 沉积（CVD），类似于用于沉积 铂族金属 因此，共沉积是可能的，这将 产生均匀成分的涂层。 在第一阶段计划中， Ultramet建议证明形成化合物的可行性 用这种方法涂覆，并测试2400 ℃下的抗氧化性。 降低PGM成分百分比的能力，以及使用 更薄的涂层将有助于保护这些稀缺的金属。

Platinum group metal (PGM) coatings have been shown to provide oxidation protection for rocket engine components operating to 2200 C. Platinum, rhodium and iridium form compounds with zirconium and hafnium. These compounds are of great interest because they are very stable, with melting points higher than those of either constituent. Furthermore, zirconium and hafnium can be formed by chemical vapor deposition (CVD) similar to processes employed for depositing platinum group metals. Codeposition is thus possible, which will produce coatings of uniform constituency. In this Phase I program, Ultramet proposes to demonstrate the feasibility of forming compound coatings in this manner and test for oxidation resistance to 2400 C. The ability to reduce the percentage of PGM Constituents, and use thinner coatings, will serve to conserve these scarce metals.