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Significant advancements have been made in the development of lightweight, high performance, carbon-carbon heat pipes for space nuclear power applications. The subject program has progressed through the concept definition and feasibility analysis stages to the current test article component fabrication and assembly phase. This concept utilizes a carbon-carbon tube with integrally woven fins as the primary structural element and radiative surface, Nb-1Zr liners to contain a potassium working fluid, and welded end caps and fill tubes. Various tests have been performed in the development of suitable liner bonding techniques and in the assessment of material stability.

High quality, reliable ceramic components are required in the Garrett/Ford AGT101 program. The purpose of this program is to demonstrate the feasibility of achieving high efficiency in a ceramic gas turbine engine. AiResearch Casting Company (ACC) has supplied most of the ceramic components qualified for testing in the AGT101 program. These components include turbine rotor, stator, shroud, inner/outer diffuser and seal ring. Except the stator, the fabrication process used is slip casting of silicon or silicon nitride powders to produce reaction bonded or sintered components. The recent high yields (> 80%) in fabrication of the above slip cast components at ACC were primarily accomplished by a better understanding of the effects of processing parameters on the microstructure and properties of the finished parts. The parameters studied include powder particle size distribution, casting slip viscosity, pH and solid content.

Friction stir processing (FSP) is a method of changing the properties of metal through intense, localized plastic deformation. This deformation is produced by forcibly inserting a non-consumable tool into a workpiece, and revolving the tool in a stirring motion as it is pushed laterally through the workpiece. It comprises of a rotating tool with pin and shoulder which are inserted into a single piece of material and traversed along the desired path to cover the region of interest. Friction between the shoulder and work piece results in localized heating which raises the temperature of the material to the range where it is plastically deformed. During this process, severe plastic deformation occurs and due to thermal exposure of material, it results in a significant evolution in the local microstructure. Carbon nanotubes were dispersed into Al matrix by multipass FSP to fabricate Al6082 T0/Fe-MWCNT.

CuSbS2 is a promising compound semiconductor for the thin film heterojunction solar cell absorber layer. The chemical spray pyrolysis technique is adopted to fabricate CuSbS2 thin film solar cells. The aqueous solution is sprayed over the soda-lime glass substrates at a constant spray rate of 10 ml/min. The films are obtained at the optimum substrate temperature of 260 °C. The thin films' of XRD spectra reveal the polycrystalline nature of the chalcostibite structure of CuSbS2, with lattice parameters of a = 0.600 nm, b = 0.380 nm, and c = 1.445 nm respectively. Micro-Raman spectra also confirm the CuSbS2 crystal phase. The optical band gap of these films is found to be 1.44 eV, which is close to the optimum band gap for maximal conversion efficiency. The optical absorption coefficient of these films is ≥ 104 cm-1. These films are found to be p-type. Finally, work on fabricating a conventional thin film heterojunction solar cell is undertaken.

Fuel cells are a promising energy source on account of their high efficiency and low emissions. Proton exchange membrane fuel cells (PEMFC) are clean and environmental-friendly power sources, which can become future energy solutions especially for transport vehicles. They exhibit good energy efficiency and high power density per volume. Working at low temperatures (<90°C), hydrogen fuelled proton exchange membrane fuel cells (PEMFCs) are identified as promising alternatives for powering autos, houses and electronics. At the middle of the proton exchange membrane (PEM) fuel cell is the membrane electrode assembly (MEA). The MEA consists of a proton exchange membrane, catalyst layers, and gas diffusion layers (GDL). However, most of the researchers have already mentioned that PEMFC are not competitive enough to rechargeable lithium ion battery with respect to price because of the rare metal used such as platinum in it.

To produce high quality appearance interior parts, precise pattern forming or gloss reduction of three-dimensional door trim cover materials are utilized. In the preparation of formed trim cover using polyvinyl chloride (PVC), prior pattern forming on original cover material or post-pattern forming with vacuum forming dies are employed. In the latter case, the die is usually made of epoxy resin. Although vacuum holes are prepared on the resin die as necessary, the lack of uniformity in air permeability causes inferior pattern transferability. In this development, special porous ceramic die is used as die material so that trim cover material can be evenly sucked through the fine pores on its surface. As a result, a door trim forming die of superior pattern transferability has realized.

The basic procedure for fabricating ceramic multilayer boards, for use with beam lead, flip chip, or flying lead semi-conductor devices is described.

High reinforcement content metal matrix composites are produced by the infiltration of molten Al alloys into preforms of ceramic particles using the PRIMEX™ pressureless metal infiltration process. These composites possess low density, very high specific stiffness, high fatigue strength, and good corrosion resistance, making them excellent candidates for automotive brake caliper applications. Most current production brake calipers are fabricated from ductile iron. Ductile iron provides good stiffness and fatigue strength, requirements for the application, but also possesses high density and poor corrosion resistance. The introduction of preform infiltrated metal matrix composites into brake caliper applications, however, has been slow due to the complex geometry. Low cost, high volume preform fabrication techniques suited to the production of full fist caliper preforms that can be subsequently infiltrated with molten Al alloy do not currently exist.

High pressure infiltration technique was applied as the actual production process to make SiC whisker(SiC-w) reinforced Al alloy composite in the SiC-w content range of 0.12 ∼ 0.35. The properties obtained here showed remarkably high elasticity, tensile strength and lower thermal expansion coefficient with other sustaining properties compared with the matrix itself. Two main problems were discussed to complete the process. One is on the specific behavior of magnesium which induces unhomogeneous distribution of it at the interface of the whisker and other one is the increase of hydrogen gas content in the body. Machinability and forginability were also discussed to make it possible to complete final shape with low cost for future commercialization.

Information related to the welding of thick titanium alloy plate for submarine hull applications is presented in this paper. The weldability of titanium alloy, welding procedures, and mechanical properties of welded joints are discussed. Welding operations are expected to present the greatest problems in fabricating titanium submarine hulls. Cutting, machining, and forming are not expected to cause major problems, but they will be more difficult to perform on titanium than on the low alloy steels now used in submarine hulls.

Titanium is a difficult material to fabricate into complex configurations. There is several elevated temperature forming processes available to produce titanium components for aerospace applications. The processes to be discussed are Superplastic Forming (SPF), hot forming and creep forming. SPF uses a tool that contains the required configuration and seals around the periphery so inert gas pressure can be used to form the material. Of the processes to be discussed, this is the one that can produce the most complex shapes containing the tightest radii. A variation of the process combines an SPF operation with diffusion bonding (SPF/DB) of two or more pieces of titanium together to produce integrally stiffened structure containing very few fasteners. Another process for shaping titanium is hot forming. In this process, matched metal tools, offset by the thickness of the starting material, are used to form the part contour at elevated temperature.

This paper documents the results of a study to compare conventional and surface scanning processes used to create total contact burn masks. Three masks were fabricated for each of five subjects using the conventional and newly developed techniques. Fit results were compared using subjective evaluations and electronic quantitative methods. The masks fabricated using surface scanning technology were rated higher overall.

The EcoCAR 2: Plugging into the Future team at the Ohio State University is designing a Parallel-Series Plug-in Hybrid Electric Vehicle capable of 50 miles of all-electric range. The vehicle features a 18.9-kWh lithium-ion battery pack with range extending operation in both series and parallel modes. This is made possible by a 1.8-L ethanol (E85) engine and 6-speed automated manual transmission. This vehicle is designed to drastically reduce fuel consumption, with a utility factor weighted fuel economy of 51 miles per gallon gasoline equivalent (mpgge), while meeting Tier II Bin 5 emissions standards. This report details the fabrication and control implementation process followed by the Ohio State team during Year 2 of the competition. The fabrication process includes finalizing designs based on identified requirements, building and assembling components, and performing extensive validation testing on the mechanical, electrical and control systems.

An advanced composite housing for the F/A-18C/D Generator Converter Unit (GCU) has been developed. The composite housing directly replaces the existing aluminum housing, and provides lighter weight and improved thermal performance. The composite housing uses IM7/954-2A material, with embedded aluminum pin fins in selected areas for thermal management. A fabrication procedure for the composite housing was developed, using matched metal compression molding, with adhesive bonding of secondary components. Two prototype housings were fabricated and will be tested for qualification.

The development of tunable diode laser systems in the 2 - 5 μm spectral region will have numerous applications for trace gas detection. To date, the development of such systems has been hampered by the difficulties of epitaxial growth, and device processing in the case of the Sb-based materials system. One of the compounding factors in this materials system is the use of aluminum containing compounds in the laser diode cladding layers. This makes the regrowth steps used in traditional lasers very difficult. As an alternative approach we are developing laterally coupled antimonide based lasers structures that do not require the regrowth steps. In this paper, the materials growth, device processing and development of the necessary drive electronics for an antimony based tunable diode laser system are discussed.

THE monocoque type of fuselage construction seems to promise satisfaction of the three requisites of prime importance; namely, high strength-weight ratio, “streamlined” form, and unobstructed interior, according to the author. The conventional method of building a fuselage consists, first, in the construction of a “form” of the required shape, upon which a layer of veneer is fastened. Other layers are applied, and thus a fuselage shell of two or three plies is completed. But the process is expensive and laborious, involving the handling and individual fitting of many small pieces. In the process described by the author, a wooden form of the exact shape of one half of the fuselage body, divided on a vertical plane passing through the center line, is built. This form, or pattern, is next suspended in a large box in which reinforcing bars previously have been woven, and concrete is poured in.

In the faceted reflector design for automotive lamps, the reflector is divided into easy-to-fabricate, circular cylindrical segments (facets) in a manner such that the reflector alone produces the beam pattern. The prescription for the facets is developed with the aid of computer programs which simulate the images from each facet and “build up” the desired light pattern mathematically, thus eliminating the normal “cut-and-try” experimental buildup. The design procedure was applied to a fog lamp with a 55 W quartz-halogen bulb and several prototypes have been constructed. The broad beam pattern from these lamps is most suitable for driving in a fog and the lamp with a clear lens offers styling flexibility. The faceted reflector concept can also be applied to headlamps, driving lamps, and signal lamps.

Results indicate the need for a redesigned Hybrid III face capable of accurate force and acceleration measurements. New instrumentation and methods for facial fracture detection were developed, including the application of acoustic emissions. Force/ deflection information for the human cadaver head and the Hybrid III ATD were generated for the frontal, zygomatic, and maxillary regions.

Facial impact experiments were conducted on eleven unembalmed human cadavers. A 32 kg or 64 kg impactor with a 25 mm diameter, rigid, cylindrical contact surface was oriented in the left-right direction relative to the face and contacted the nose at the elevation of the infraorbital margins. The impactor was propelled toward the race along an anterior-to-posterior path, with contact velocities ranging from 10 to 26 km/h. Accelerometers mounted on the impactor and the occiput provided data for analyzing the dynamics of the impacts. While the threshold for nasal bone fractures was not determined, it appears that a peak force of about 3 kN (filtered 180 Hz) is a representative threshold for more severe fracture patterns. A preliminary dynamic force vs penetration response specification for the above mode of loading is offered.

Measuring facial lacerations during simulated car crashes has remained a problem when testing crashworthiness safety performance. A method is presented based on the use of two chamois skins which cover dummy headforms, acting as a surrogate for human skin. Measurements of facial laceration obtained using the double chamois technique during car crash testing are placed into one of two categories using a Chamois Laceration Scale (CLS): pass or fail. Pass represents a “go” condition denoting an acceptable tolerance level while fail represents a “no-go” condition. The criterion for pass, i.e., a passing or acceptable tolerance level, permits slight abrasions and very minor lacerations, but does not permit any cuts in the inner of the two layers of chamois skin. Data are presented to substantiate the objectivity of this measurement procedure.