Covering solid, film cooled surfaces with a duplex thermal barrier coating

Thermal barrier coating systems were applied to hardware having passageways in the walls connecting apertures in the surface to a gas supply for film cooling. An inert gas, such as argon, is discharged through the apertures during the application of the thermal barrier coating system by plasma spraying. This flow of inert gas reduces both blocking of the holes and base metal oxidation during the coating operation

Microstructural Characterization of Shrouded Plasma-Sprayed Titanium Coatings

Titanium and its alloys are often used for corrosion protection because they are able to offer high chemical resistance against various corrosive media. In this paper, shrouded plasma spray technology was applied to produce titanium coatings. A solid shroud with an external shrouding gas was used to plasma spray titanium powder feedstock with aim of reducing the oxide content in the as-sprayed coatings. The titanium coatings were assessed by optical microscope, scanning electron microscopy, X-ray diffraction, LECO combustion method and Vickers microhardness testing. The results showed that the presence of the shroud and the external shrouding gas led to a dense microstructure with a low porosity in the plasma-sprayed titanium coatings. The oxygen and nitrogen contents in the titanium coating were kept at a low level due to the shielding effect of the shroud attachment and the external shrouding gas. The dominant phase in the shrouded titanium coatings was mainly composed of α-Ti phase, which was very similar to the titanium feedstock powders. The shrouded plasma-sprayed titanium coatings had a Vickers microhardness of 404.2 ± 103.2 HV

Method of making carbide/fluoride/silver composites

A composition containing 30 to 70 percent chromium carbide, 5 to 20 percent soft noble metal, 5 to 20 percent metal fluorides, and 20 to 60 percent metal binder is used in a powdered metallurgy process for the production of self-lubricating components, such as bearings. The use of the material allows the self-lubricating bearing to maintain its low friction properties over an extended range of operating temperatures

Multilayer refractory nozzles produced by plasma-spray process

Multilayer rocket nozzles formed by plasma spraying have good thermal shock resistance and can be reheated in an oxidizing environment without loss of coating adherence. Suggested application of this process are for the production of refractory components, which can be formed as surfaces of revolution

Controlling the Microstructure of Arc Sprayed Shells

Techniques for controlling the microstructure of sprayed steel structures are discussed in this paper. Steel is arc sprayed onto shaped substrates to form tooling. The quality of the tool is greatly influenced by the microstructure of the material and the interlamella regions of the deposit. This work is focused on characterizing the microstructure, improving the state of the inter-lamella regions, and discusses our success in forming pseudo-alloys and graded shells by mixing sprayed materials. Microstructure control has interesting implications for other research as well, such as the MASK & DEPOSITS approach of forming objects.Mechanical Engineerin

Process for glass coating an ion accelerator grid Patent

Helium outgassing process for fused glass coating on ion accelerator gri

High temperature surface protection

Alloys of the MCrAlX type are the basis for high temperature surface protection systems in gas turbines. M can be one or more of Ni, Co, or Fe and X denotes a reactive metal added to enhance oxide scale adherence. The selection and formation as well as the oxidation, hot corrosion and thermal fatigue performance of MCrAlX coatings are discussed. Coatings covered range from simple aluminides formed by pack cementation to the more advanced physical vapor deposition overlay coatings and developmental plasma spray deposited thermal barrier coatings

Novel applications for TAZ-8A

Recent needs in the non-aerospace industrial sector have revitalized interest in high performance alloys. TAZ-8A has a combination of properties that makes it unique: a high temperature strength, oxidation resistance, abrasion resistance, and exceptional thermal shock resistance. The major drawback for the utilization of this alloy is the relatively high cost compared with the more common iron base alloys. Reduced material consumption and lower costs are possible by using coatings of TAZ-8A on a low cost substrate. Coatings were applied using plasma spray techniques developed by NASA as well as modified plasma vapor deposition (PVD) techniques

A critical review of experimental accomplishments in the field of filament-reinforced metal matrix composites Bimonthly progress report

Critical review of experimental accomplishments in filament reinforced metal-matrix composite

Bearing material

A composite material is described which will provide low friction surfaces for materials in rolling or sliding contact and is self-lubricating and oxidation resistant up to and in excess of about 930 C. The composite is comprised of a metal component which lends strength and elasticity to the structure, a fluoride salt component which provides lubrication and, lastly, a glass component which not only provides oxidation protection to the metal but may also enhance the lubrication qualities of the composite