Feasibility Investigation for Performing Fireball Temperature Tests

NASA Johnson Space Center White Sands Test Facility (WSTF) was requested by the Launch Abort Subpanel and the Power Systems Subpanel of the Interagency Nuclear Safety Review Panel to investigate the feasibility of using spectroscopic techniques to measure propellant fireball gas temperatures. This report outlines the modeling and experimental approaches and results of this investigation. Descriptions of the theoretical particle temperature and mass effusion models are presented along with the results of the survivability of small plutonium dioxide (less than or equal to 1000 microns diameter) particles entrained in various propellant fireball scenarios. The experimental test systems used to measure the hydroxide radical, water, and particle graybody spectral emissions and absorptions are discussed. Spectral results along with temperatures extracted by analyzing the spectral features are presented for the flames investigated in the laboratory environment. Methods of implementing spectroscopic measurements for future testing using the WSTF Large-scale Hydrogen/Oxygen Explosion Facility are discussed, and the accuracy expected for these measurements is estimated from laboratory measurements

Kinetic Metallization Repair of Alclad

Abstract Cladding is a common method of providing corrosion protection of aluminum alloys, which forms an anodic layer in direct and intimate contact with the alloy sheet during cold roll processing. A structural aluminum alloy is clad in a thin layer of a higher purity alloy that is more galvanically reactive. Common examples include 1230 clad on 2024, and 7072 clad on 6061 and 7075. If this clad layer is damaged or removed the underlying structural alloy is exposed and susceptible to corrosion and/or stress corrosion cracking. Kinetic Metallization is a low temperature deposition technique compliant with MIL-STD-3021 that enables repair or replacement of worn or damaged clad layers. Aluminum or Al-Trans coatings are deposited as a new clad coating, and can be subsequently polished to the same mirror finish as the original clad surfaces. This paper presents the techniques developed for repairing worn or damaged Al clad surfaces using the economical Kinetic Metallization process and the qualification tests performed to date for various feedstock powder formulations (Ref 1).</jats:p

Kinetic Metallization of Interior Diameter Bores

Abstract The Kinetic Metallization (KM) process allows the coating and dimensional restoration of interior diameter (ID) surfaces. It is a low temperature, low pressure, solid-state deposition process that is compliant with the recent MIL-STD-3021 cold spray materials deposition standard. The unique attribute of preheating powder particles to enhance ductility within the Kinetic Metallization process allows for high quality coating deposition onto the inner diameter of small-bore components using very short sonic nozzles. Inovati has developed a KM ID Spray Gun that can deposit a coating normal to the surface of the bore down to interior diameter sizes of 80-mm, with depth-to-diameter ratios exceeding 10-to-1. These ID deposition guns, when used with KM systems, can deposit the full range of coatings including structural aluminum alloys for rebuilding damaged forgings, superalloys for corrosion and/or oxidation protection, and hard-phase carbide coatings for wear resistance. This paper presents a case study for rebuilding of damaged 7075-Al forged landing gear outer cylinders requiring ID coating repairs of 0.020-0.030 inches in thickness. A separate study focuses on tungsten-carbide cobalt (WC-17Co) on steel liners and actuating cylinders for replacing hard chrome coatings and repairing worn cylinder bores.</jats:p

Kinetic Metallization Repair of Ion Vapor Deposited Aluminum Coatings

Abstract The repair of damaged Ion Vapor Deposition Aluminum coatings on high strength steel aircraft components has generally required the use of brush plating with hazardous materials including cadmium. Inovati has developed a unique Al-Trans (aluminum-transition metal) coating using the Kinetic Metallization process that permits repairs of IVD-Al coatings on high strength steels. Originally the Al-Trans coating formulation was developed for commercial application on telecommunication equipment steel racks as an electrically conductive grounding strip with excellent corrosion resistance. Recent research was completed with NAVAIR to further develop this coating formulation and the Kinetic Metallization process for repair of IVD-Al coatings on aircraft components. This presentation will describe the KM repair process and the tests completed to qualify the repaired coatings. Inovati has recently developed a KM-Mobile Coating System with a handheld Spray Gun for the field repair of corrosion damaged magnesium and aluminum alloy aircraft components.</jats:p

Military Adoption of Kinetic Metallization

Abstract The low temperature Kinetic Metallization (KM) deposition process is compliant with the recently revised MIL-STD-3021 standard for cold spray materials deposition. KM deposition process and equipment was supported through the US Military via multiple Small Business Innovative Research (SBIR) grants leading to delivery of KM deposition equipment to multiple branches. Coating application areas discussed in this paper include wear resistant tungsten-carbide and chromium-carbide hard-phase coatings. These are used for aircraft engines and landing gear surfaces with firm low temperature deposition requirements. Other areas include aluminum and magnesium dimensional restorations, in particular for Aircraft Mounted Accessory Drive (AMAD) gearboxes for F-18 platforms, and land vehicle housings and casings for the US Marines Corps.</jats:p

QNDE Techniques for Measuring the Dimensions of Adhesive and Fiberglass Bonds Securing the Pivots in the Hard Upper Torso of the Extravehicular Mobility Unit or Spacesuit

Methods for evaluating and measuring adhesive bonds in multi-layer anisotropic composite materials are of considerable interest to the aerospace community. Recent quantitative nondestructive evaluation (QNDE) research has concentrated on using obliquely incident ultrasonic waves to determine interfacial degradation in adhesive bonds [1]. For anisotropic materials, this task is more formidable, but the theoretical analysis presented by Balasubramaniam et. al. [2] indicates good prospects for the ultrasonic reflection technique. The primary objective of this experimental investigation was to determine the best QNDE method for measuring the relative thickness of fiberglass/epoxy (Fg/Ep) laminate compared to the adhesive layer bonding a stainless steel pivot in the composite structure of the Hard Upper Torso (HUT). The integrity of the interfacial bonds between the adhesive, the stainless steel pivot, and the composite laminate was also of interest, but of secondary importance to the project.</p

Kinetic Metallization of Ceramic Armor Tiles

Abstract Ceramic tiles are widely used as ballistic armor due to their ability to absorb high specific impact energy. However, ceramic materials often exhibit very low ductility and have a tendency to exhibit multiple fractures in spider-web patterns around the point of impact. One method used to introduce ductility is to encapsulate the tile in a metal jacket, or to provide a strongly adhered metallic backing plate. Aluminum and titanium metals are of primary interest to decrease the overall weight of the armor material system. The low temperature Kinetic Metallization (KM) process allows direct deposition of the metals onto the ceramic tiles. This is not possible with thermal spray processes due to the extreme mismatch in thermal expansion and adverse metallic-ceramic chemical reactions at high temperatures. Kinetic Metallization has been used to deposit aluminum and titanium coatings onto silicon carbide (SiC) and proprietary ceramic matrix composite (CMC) tiles. Ballistic testing of coated tiles has shown decreased fracturing of the armor material, leading to improved performance for subsequent impacts.</jats:p