Systems and Methods for Implementing Bulk Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

Bulk metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a strain wave gear includes: a wave generator; a flexspline that itself includes a first set of gear teeth; and a circular spline that itself includes a second set of gear teeth; where at least one of the wave generator, the flexspline, and the circular spline, includes a bulk metallic glass-based material

Systems and Methods for Implementing Tailored Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

Systems and methods in accordance with embodiments of the invention implement tailored metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a method of fabricating a flexspline of a strain wave gear includes: forming a MG-based composition into a flexspline using one of a thermoplastic forming technique and a casting technique; where the forming of the MG-based composition results in a formed MG-based material; where the formed flexspline is characterized by: a minimum thickness of greater than approximately 1 mm and a major diameter of less than approximately 4 inches

Laser welding of Ti6Al4V alloy by disk laser: analysis and optimization

2010 - 2011Titanium alloys have been successfully applied in many industrial fields because of their better performance and lighter weight than other commonly used structural materials. The conventional welding methods used for titanium alloys are tungsten inert gas (TIG) and plasma arc welding. In recent decades, autogenous processes with highly concentrated energy sources have become popular; these joining processes are laser and electron-beam welding. The power source can be concentrated in very small areas so as to achieve energy densities up to 10,000 times higher than those of the arc processes. Laser welding allows joints to be made with limited distortion. The fullyautomated process, ensures high productivity and high-quality joints. Laser technology is acquiring industrial interest because the electron-beam processes have limitations, such as the need to operate in vacuum, the increased costs and the emission of X-rays. Titanium alloys are widely used in the aircraft industry, because of their high strength-to-weight ratio, corrosion resistance, operating temperature and bonding with composite materials (electrochemical compatibility, similar coefficients of thermal expansion). The criteria for the design, manufacture and operation were changed to obtain structures that are lighter and more efficient than the ones made of aluminum. However, the structures in carbonfiber- reinforced-polymer require the use of metal structures, especially in areas of great concentration of loads. In spite of several advantages, these alloys lead to excessive manufacturing costs related to the cost of the raw materials, the high volumes of waste and the complex and expensive finishing. For these reasons, it is cheaper to produce semi-finished products by welding simpler parts, instead of casting and forming processes; therefore, laser welding can be used due to its high productivity and quality end-products. The aim of the thesis work is to find the better input process parameters values to weld 3 mm and 1 mm Ti6Al4V sheets using a 2 kW Yb:YAG disk laser. Both bead on plate and butt tests have been performed, and the beads quality is characterized in terms of geometric features, porosity content, microstructure, hardness and strength. This work is organized in five chapters. Chapter 1 discusses the principles of operation and the different types of laser including disk laser, used in the experimental part. Chapter 2 presents the properties of titanium and its alloys, highlighting the various fields of application. Chapter 3 presents a review of the different technologies used for welding of titanium alloys, focusing primarily on laser welding and its mechanisms. Chapter 4 describes the titanium alloy, equipment and methodologies used in the experimental work. Finally, Chapter 5 presents the results obtained. [edited by author]X n.s

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Printed and drawn flexible electronics based on cellulose nanocomposites

Sustainability, flexibility, and low-power consumption are key features to meet the growing re- quirements of simplicity and multifunctionality of low-cost, disposable/recyclable smart electronic -of- -based composites hold po- tential to fulfill such demands when explored as substrate and/or electrolyte-gate, or as active channel layer on printed transistors and integrated circuits based on ionic responses (iontronics). In this work, a new generation of reusable, healable and recyclable regenerated cellulose hydro- gels with high ionic conductivity and conformability, capable of being provided in the form of stick- ers, are demonstrated. These hydrogels are obtained from a simple, fast, low-cost, and environ- mental-friendly aqueous alkali salt/urea dissolution method of native cellulose, combined with eration and simultaneous ion incorporation with acetic acid. Their electrochemical properties can be also merged with the mechanical robustness, thermal resistance, transparency, and smooth- - strate. Beyond gate dielectrics, a water-based screen-printable ink, composed of CMC binder and com- mercial zinc oxide (ZnO) semiconducting nanoparticles, was formulated. The ink enables the printing of relatively smooth and densely packed films on office paper with semiconducting func- tionality at room temperature. The rather use of porous ZnO nanoplates is beneficial to form per- colative pathways at lower contents of functional material, at the cost of rougher surfaces. The engineered cellulose composites are successfully integrated into flexible, recyclable, low- voltage (<3.5 V), printed electrolyte-gated office paper or on the ionically modified nanopaper. Ubiquitous calligraphy accessories are used -the- out on the target substrate, where are already printed the devices. Such concept paves the way for a worldwide boom of creativity, where we can freely create personal electronic kits, while having fun at it and without generating waste.Sustentabilidade, flexibilidade e baixo consumo energético são características chave para atender aos crescentes requisitos de simplicidade e multifuncionalidade de sistemas eletrónicos inteligentes de baixo custo, das- Compósitos à base de celulose têm potencial para atender a tais necessidades quando explora- dos como substrato e/ou porta-de-eletrólito ou como camada de canal ativo em transístores impressos e circuitos integrados baseados em respostas iónicas (iontronics). Neste trabalho, é demonstrada uma nova geração de hidrogéis reutilizáveis, reparáveis e recicláveis baseados em celulose regenerada, que apresentam alta condução iónica e conformabilidade, podendo ser fornecidos na forma de adesivos. Estes hidrogéis são obtidos a partir de um método simples, rápido, barato e amigo do ambiente que permite a dissolução de celulose nativa em soluções aquosas com mistura de sal alcalino e ureia, combinado com carboximetil celulose (CMC) para melhorar a sua robustez, seguido da regeneração e simultâneo enriquecimento iónico com ácido acético. As suas propriedades eletroquímicas podem ser combinadas com a inbase de celulose micro/nanofibrilada para obter um substrato eletrolítico semelhante a papel. Para além de portas-dielétricas, foi formulada uma tinta aquosa compatível com serigrafia, composta por CMC como espessante e nanopartículas semicondutoras de ZnO. A tinta permite a impressão de filmes pouco rugosos e densamente percolados sobre papel de escritório, e com funcionalidade semicondutora à temperatura ambiente. O uso alternativo de nanoplacas porosas de ZnO é benéfico para criar caminhos percolativos com menores teores de material funcional, apesar de se obter filmes rugosos. Os compósitos à base celulose foram integrados com sucesso em transístores e portas lógicas porta-eletrolítica, os quais foram impressos em papel de escritório ou no "nanopapel" iconicamente modificado. Acessórios de caligrafia permitem a fácil e rápida padronização de pistas condutoras/resistivas, desenhando-as no substrato alvo, onde estão impressos os dispositivos. Este conceito despoleta um mundo criativo, onde é possível criar livremente kits eletrónicos customizados de forma divertida e sem gerar resíduos

Bibliography of Lewis Research Center Technical Publications announced in 1991

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific engineering work performed and managed by the Lewis Research Center in 1991. All the publications were announced in the 1991 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

Structural Framework for Flight II: NASAs Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This monograph is organized to highlight the successful application of light alloys on aircraft and space launch vehicles, the role of NASA in enabling these applications for each different class of flight vehicles, and a discussion of the major advancements made in discipline areas of research. In each section, key personnel and selected references are included. These references are intended to provide additional information for technical specialists and others who desire a more in-depth discussion of the contributions. Also in each section, lessons learned and future challenges are highlighted to help guide technical personnel either in the conduct or management of current and future research projects related to light-weighting advanced air and space vehicles

Innovation: Key to the future

The NASA Marshall Space Flight Center Annual Report is presented. A description of research and development projects is included. Topics covered include: space science; space systems; transportation systems; astronomy and astrophysics; earth sciences; solar terrestrial physics; microgravity science; diagnostic and inspection system; information, electronic, and optical systems; materials and manufacturing; propulsion; and structures and dynamics