Low Damage Drilling of CFRP/Titanium Compound Materials for Fastening

The electromechanical properties of elastomer material change when different levels of stretching are applied to the elastomer film. The generated stress and expansion of the EAP material depend on the electric field across the material and its relative permeability. Some of the best known commercial dielectric elastomer materials are based on acrylic elastomers, e.g. 3M VHB 4910 or 4905 adhesive tape. In this work, the VHB 4910 tape was used as a reference material for different types of acrylic nanoclay compound materials. These new type of nanoclay elastomer compounds were tested because the addition of clay into the elastomer was assumed to increase its actuating performance. Different voltage and pre-stretching levels were used in the measurements. Current-voltage characteristics and isometric stress measurements were used to study the energy efficiency, frequency dependent behavior, reactivity and isometric stress performance of the EAP materials. Based on the electromechanical characterization and material properties, a general hyperelastic material model was developed. According to the preliminary tests, the nanoclay compound seems to be a bit stiffer than VHB 4910 resulting in a greater isometric stress response.

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Electron Micro Technology Study on BN Fiber’s Microcosmic Structure and Mechanics Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.588-589.104 ◽

2012 ◽

Vol 588-589 ◽

pp. 104-107

Author(s):

Qing Tian Li

Keyword(s):

Mechanical Properties ◽

Scientific Basis ◽

Manufacturing Technology ◽

Technology Study ◽

Compound Material ◽

Transmission Electron ◽

Anti Oxidant ◽

Micro Technology ◽

Compound Materials ◽

Analytical Technology

This paper uses transmission electron microscope technology, studies microcosmic structure’ s feature of BN fiber, clarifies existing crystal structure’s state of BN fiber during its producing and transform course. It is studied that BN fiber has a sound mechanical properties, which most of crystalline phase is turbine layer phase and whose nitrogen is high and size is small .During the course of BN fiber’s producing, adding suitable tension from axial can promote directional arrange of BN fiber’s surface crystalline grain and put forward the improving direction of manufacturing technology in order to improve materials’ mechanical properties. BN fiber(indicated by BNf) is a kind of new inorganic material. Because of its fine stable, corrosion-resisting, anti-oxidant properties and high ability of absorbing neutron and so on, it is attached more and more importance and it get constant development and usefulness. BNf and ceramics, metal, various compound materials made of resin material can be used in metallurgy, electron, aviation etc science and technology fields. But the intensity of BNf and its elasticity modulus are lower than basic fundamental material. When BNf’s compound material get fine properties above mentioned, the mechanics properties of the material will drop. So its application degree will be limited to a certain extent. In order to improve and raise BNf’s mechanics properties, this essay makes use of electron micro analytical technology to study its microcosmic structure and mechanics properties, providing scientific basis for designing reasonable manufacturing technology.

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Restricted Hartree-Fock calculations on the interaction of an olefine with a titanium compound

Chemical Physics Letters ◽

10.1016/0009-2614(77)80431-4 ◽

1977 ◽

Vol 49 (1) ◽

pp. 8-12 ◽

Cited By ~ 24

Author(s):

G. Giunchi ◽

E. Clementi ◽

M.E. Ruiz-Vizcaya ◽

O. Novaro

Keyword(s):

Hartree Fock ◽

Titanium Compound

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Epoxy antifriction wollastonite-filled materials

Vestnik MGSU ◽

10.22227/1997-0935.2019.3.311-321 ◽

2019 ◽

pp. 311-321

Author(s):

Elena M. Gotlib ◽

Аlmira R. Khasanova ◽

Engel R. Galimov ◽

Аlla G. Sokolova

Keyword(s):

Wear Resistance ◽

Friction Coefficient ◽

Adhesion Strength ◽

Quaternary Ammonium ◽

Epoxy Compound ◽

Quaternary Ammonium Salts ◽

Ammonium Salts ◽

Antifriction Properties ◽

The Impact ◽

Compound Materials

Introduction. Domestic mineral natural-origin filler ‘wollastonite’, also known as calcium methyl silicate, is widely used as a base for wear-resisting epoxy antifriction materials. Due to anisodiametric shape of its particles, wollastonite functions as a micro reinforcement fibre enhancing adhesion strength and wear resistance of epoxy compositions, improving their antifriction properties, especially when organomodifying by quaternary ammonium salts. In this regard, the investigation of the impact of chemical composition of such surfactants as quaternary ammonium salts on the properties of epoxy compound materials presents utmost interest for researchers developing low-friction materials. Materials and methods. Epoxy diane resin ED-20 was hardened with aminoalkylphenol AF-2. Content of epoxy hardener was determined by equimolar ratio of epoxy groups to amine groups. Domestic wollastonite of the grade Miwoll 10-97 was used as filler, particle length to the diameter correlated as 15:1. The wollastonite surface was activated with surfactants belonging to domestically produced quaternary ammonium salts. Wear resistance of specimens was tested by means of the vertical optical caliper IZV-1. Friction coefficient was estimated with the assistance of the computer-automated frictional machine CSM Instruments Tribometer. Adhesion strength of glue joint was determined as per GOST 28840-90 standard. Two bars of sheet aluminium were used as glued surfaces as per GOST 14759-69 standard. Results. Reduction of wear of epoxy coatings when modified with micro reinforcing wollastonite can be explained by the increase of cross-linking degree of the polymer. The length of alkyl radical of quaternary ammonium salts used for wollastonite surface activation affects the intervals between the epoxy links. As the quaternary ammonium salt chain length is growing, wear of epoxy materials is reducing. Introduction of the wollastonite containing metallic oxides in the epoxy composites increases wear resistance and adhesion strength and reduces coating friction coefficients. Conclusions. Hardened with the AF-2 and filled with the wollastonite of the Miwoll 10-97 grade, the epoxy compound materials have enhanced wear resistance and adhesion strength and lower friction coefficient. The best result is observed when applying wollastonite modified with a surfactant belonging to the class of quaternary ammonium salts. The wollastonite can be used for practical purposes as a perspective reinforcing agent for epoxy materials with improved wear resistance, enhanced adhesion to metals and reduced friction coefficient.

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High-Efficiency GaAs-Based Solar Cells

10.5772/intechopen.94365 ◽

2020 ◽

Author(s):

Masafumi Yamaguchi

Keyword(s):

Solar Cells ◽

Radiative Recombination ◽

High Efficiency ◽

Single Junction ◽

Analytical Results ◽

Key Issues ◽

Limiting Efficiency ◽

Compound Materials

The III-V compound solar cells represented by GaAs solar cells have contributed as space and concentrator solar cells and are important as sub-cells for multi-junction solar cells. This chapter reviews progress in III-V compound single-junction solar cells such as GaAs, InP, AlGaAs and InGaP cells. Especially, GaAs solar cells have shown 29.1% under 1-sun, highest ever reported for single-junction solar cells. In addition, analytical results for non-radiative recombination and resistance losses in III-V compound solar cells are shown by considering fundamentals for major losses in III-V compound materials and solar cells. Because the limiting efficiency of single-junction solar cells is 30-32%, multi-junction junction solar cells have been developed and InGaP/GaAs based 3-junction solar cells are widely used in space. Recently, highest efficiencies of 39.1% under 1-sun and 47.2% under concentration have been demonstrated with 6-junction solar cells. This chapter also reviews progress in III-V compound multi-junction solar cells and key issues for realizing high-efficiency multi-junction cells.

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THE VAPOR PHASE POLYMERIZATION OF ETHYLENE ON AN ORGANOTITANIUM CATALYTIC SURFACE

Canadian Journal of Chemistry ◽

10.1139/v63-179 ◽

1963 ◽

Vol 41 (5) ◽

pp. 1265-1275 ◽

Cited By ~ 11

Author(s):

F. H. C. Edgecombe

Keyword(s):

Gas Phase ◽

Constant Pressure ◽

Solid Catalyst ◽

Analogue Computer ◽

First Order ◽

Titanium Compound ◽

Volume State ◽

Rate Of Polymerization ◽

Order Case ◽

Vapor Phase Polymerization

The polymerization of ethylene has been studied in the gas phase on a solid catalyst formed by the reaction of an organotitanium vapor with a solid crystalline titanium compound deposited on the walls of a reaction vessel.The rate of polymerization of ethylene was found to be, initially, of first order but as the reaction proceeded departure from the first-order case was observed.Experiments conducted under the condition of constant pressure as well as the usual constant-volume state enabled us, with the aid of an analogue computer, to devise a mathematical model which explained the experimental results in an unique fashion.A measure of the rate constant for catalyst decay was also obtained as well as the activation energy for the overall propagation step in the polymerization of ethylene.

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