Progress in Fabrication of Rocket Combustion Chambers by VPS
- Thursday, 21 December 2006
Several documents in a collection describe aspects of the development of advanced materials and fabrication processes intended to enable the manufacture of advanced rocket combustion chambers and nozzles at relatively low cost. One concept discussed in most of the documents is the fabrication of combustion-chamber liners by vacuum plasma spraying (VPS) of an alloy of 88Cu/8Cr/4Nb (numbers indicate atomic percentages)—a concept that was reported in "Improved Alloy for Fabrication of Combustion Chambers by VPS" (MFS-26546), NASA Tech Briefs, Vol. 23, No.1 (January 1999), page 50. Another concept is the deposition of graded-composition wall and liner structures by VPS in order to make liners integral parts of wall structures and to make oxidation-and thermal- protection layers integral parts of liners: The VPS process is started at 100 percent of a first alloy, then the proportion of a second alloy is increased gradually from zero as deposition continues, ending at 100 percent of the second alloy. Yet another concept discussed in one of the documents is the VPS of oxidation-protection coats in the forms of nickel-and-chromium-containing refractory alloys on VPS-deposited 88Cu/8Cr/4Nb liners.