Composite properties

Among the rarest of all meteorites are the lunar meteorites. Isotopic, mineralogical, and compositional properties of these samples provide positive identification as lunar samples because of the unique properties of lunar materials that have been discovered by extensive analyses of lunar materials returned by the manned ApoUo and unstaffed Luna missions. AH but one of the lunar meteorites that have been found to date have been recovered from Antarctica. 

Composition property values can vary from batch to batch. 

The quality of bonding is related direcdy to the size and distribution of solidified melt pockets along the interface, especially for dissimilar metal systems that form intermetaUic compounds. The pockets of solidified melt are brittle and contain localized defects which do not affect the composite properties. Explosion-bonding parameters for dissimilar metal systems normally are chosen to minimize the pockets of melt associated with the interface. 

K. K. Chawla in MetalMatrix Composites Properties, Academic Press, Inc., San Diego, Calif., 1991. 

The water hberated during the cure has no apparent effect on the composite properties. Glass-filled composites prepared in this manner retain mechanical properties at elevated temperatures as well as solvent and flammabiUty resistance (88). PhenoHc-graphite-fiber composites that exhibit superior mechanical properties have also been prepared by this process. 

Vendor information (available materials, their composition, properties and applications available sizes, shapes and geometry availability, delivery schedule, cost and performance data)... 

R. N. Traxler, Its Composition, Properties and Uses, Reinhold Publishing Co., New York, 1961, Chapt. 6. 

Because these alloys are precipitation hardenable, they can be customized for specific requirements across a wide range of property combinations. Advances in composition control, processing, and recycling technology have broadened the capabiUties and expanded the range of appHcation. Data sheets pubhshed by the manufacturers and others (41) give compositions, properties, and typical appHcations. 

It is critical that surface treatment conditions be optimized to composite properties since overtreatment as well as undertreatment will degrade composite properties. Typically composite interlaminar shear strength (ILSS), in-plane shear, and transverse tension ate used to assess the effectiveness of surface treatment. More recently damage tolerance properties such as edge delamination strength, open hole compression, and compression after impact have become more important in evaluating the toughness of composite parts. 

The demand for cement was stimulated by the growth of canal systems ia United States duting the nineteenth century. Process improvements were made ia the calciaation of certain limestones for the manufacture of natural cements, which were gradually displaced by Pordand cement. This latter was named ia a 1824 patent because of its color and resemblance to a natural limestone quarried on the Isle of Pordand ia England. Research conducted siace that time has provided a clear picture of the composition, properties, and fields of stabiUty of the principal systems found ia Pordand cement. These results led to the widely used Bogue calculation of composition based on oxide analysis (1). Details beyond the scope of this article may be found ia the Hterature (2). 

The composition, properties, and size of soot particles collected from flame products vary considerably with flame conditions and growth time. Typically the C—H atomic ratio ranges from two to five and the particles consist of kregular chains or clusters of tiny spheres 10—40 nm in diameter with overall dimensions of perhaps 200 nm, although some may agglomerate further to much larger sizes. 

M is the composite property (E 23) corresponding fiber and matrix properties. The principal problem ia the appHcation of... 

The highly polar nature of the TGMDA—DDS system results in high moisture absorption. The plasticization of epoxy matrices by absorbed water and its effect on composite properties have been well documented. As can be seen from Table 4, the TGMDA system can absorb as much as 6.5% (by weight) water (4). This absorbed water results in a dramatic drop in both the glass transition temperature and hot—wet flexural modulus (4—6). 

The stmcture of reinforcements can be either equiaxed or acicular. The nature of their placement within a composite, the composite architecture, is critical to the resultant composite properties. Possible architectures are summarized in Figure 1. 

Fig. 1. Reinforcement aichitectuies foi ceiamic—matrix composites and corresponding composite properties, (a) Spherical particles (b) platelets, whiskers,...

Note the importance of matrix modulus on composite properties (54). To convert GPa to psi, multiply by 145,000. 

Ceramic matrix composites are candidate materials for high temperature stmctural appHcations. Ceramic matrices with properties of high strength, hardness, and thermal and chemical stabiUty coupled with low density are reinforced with ceramic second phases that impart the high toughness and damage tolerance which is required of such stmctural materials. The varieties of reinforcements include particles, platelets, whiskers and continuous fibers. Placement of reinforcements within the matrix determines the isotropy of the composite properties. 

Physical property specifications placed on the composition of the final produc t. For blends of various products, we usually assume that a composite property can be calculated through the averaging of pure component physical properties. 

J. Wright and A. Colling, Seawater its Composition, Properties and Behaviour, Peigainon Press,... 

Occurrence and preparation Chemical composition Properties Applications... 

There are slight differenees between BSS and ASTM compositions. Properties in brackets are indicative, not mandatory. 0.2% proof stress. ... 

L. R. Herrmann and K. S. Pister, Composite Properties of Filament-Resin Systems, ASME Paper 63-WA-239, ASME Winter Annual Meeting, Philadelphia, Pennsylvania, 17-22 November 1963. 

Flow behavior of the polymer blends is determined by their structure, which is governed by the degree of dispersion of the component and by the mode of their distribution. For blends having identical compositions, it is possible to produce systems in which one and the same component may be either a dispersion medium or a dispersed phase [1]. This behavior of the polyblend systems depends on various parameters, the most important of which is the blending sequence. It is, therefore, difficult to obtain a uniform composition property relationship for the polymer blends even though the composition remains identical. 

The treatment of blends as a two phase system opened up an interesting field of modifying the composite properties by the use of a (third component within the interface boundaries, which is termed as compatibilizers [1]. Such modifications are still being extended to the formation of microgel out of the interaction between the two blend partners having a reactive for functionalities. This type of interchain crosslinking does not require any compatibilizer to enhance the blend properties and also allows the blends to be reprocessed by further addition of a curative to achieve still further improved properties [3,4]. Such interchain crosslinking is believed to reduce the viscoelastic mismatch between the blend partners and, thus, facilitates smooth extrusion [5,6]. 

This constant value can be taken in turn into the composite functions to calculate the composite properties. A calculation result is illustrated in Fig. 25. For the four sample groups, the calculated layer moduli , are uneven in the cross-section within a composite sample group. The lowest value is still located in the core layer due to the lower deformation and, therefore, the lower... 

One of the important factors affecting composite properties is the amount of fiber it contains, i,e., percentage by volume. 

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