Composite Materials: Interest and Physical Properties

2014 ◽  
pp. 27-40
Keyword(s):  
Composite Materials ◽  
Physical Properties

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

Microstructure and Physical Properties of Clay-Polymer Composites

2000 ◽  
Vol 628 ◽  
Author(s):  
T.N. Blanton ◽  
D. Majumdar ◽  
S.M. Melpolder
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Polymer Composites ◽  
Basal Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layered Clay

ABSTRACTClay-polymer nanoparticulate composite materials are evaluated by the X-ray diffraction technique. The basal plane spacing provided information about the degree of intercalation and exfoliation of the 2: 1 layered clay structure. Both intercalation and exfoliation are controlled by the identity of the polymer and the clay:polymer ratio.

scholarly journals The Effects of Physical Properties of Fibers in Nettle Fiber/Polyester Composites on the Thermal Conductivity Coefficient

2018 ◽  
Vol 1 (1) ◽  
pp. 834-842
Author(s):  
Murat Koru ◽  
Kenan Büyükkaya
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Physical Properties ◽  
Thermal Conductivity Coefficient ◽  
The Black Sea ◽  
Stinging Nettle ◽  
Fiber Concentration ◽  
Black Sea Region ◽  
Polyester Composites ◽  
Materials Used

The physical properties of the materials used are also important in the thermal conduction, besides many other factors. In this study, nettle fiber/polyester composites were formed using stinging nettle grown in the Black Sea region. The stinging nettle fibers used in the formation of these composites were divided into three parts as bottom, middle, and top. The physical properties (diameter, density, crystallinity) of the fibers obtained from different parts of the plant and how the increased fiber concentration affected the thermal conductivity coefficients of the composite materials formed were studied. As a result, it was observed that the thermal conductivity coefficients of the composites increased with the increase of the crystallinity ratio of the fiber. Moreover, the increased fiber concentration significantly increased the thermal conductivity coefficient of the composite materials produced.

Influence of Palm Oil Fibers Length Variation on Mechanical Properties of Reinforced Crude Bricks

2022 ◽  
Author(s):  
Mazhar Hussain ◽  
Daniel Levacher ◽  
Nathalie Leblanc ◽  
Hafida Zmamou ◽  
Irini Djeran Maigre ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Composite Materials ◽  
Physical Properties ◽  
Palm Oil ◽  
Mechanical Characteristics ◽  
Natural Fibers ◽  
Indirect Tensile

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.

Polysaccharide nano crystal reinforced nanocomposites

2008 ◽  
Vol 86 (6) ◽  
pp. 484-494 ◽  
Author(s):  
Alain Dufresne
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
High Performance ◽  
Volume Fraction ◽  
Thermal Stabilization ◽  
Nano Particles ◽  
Strong Interactions ◽  
Nano Composite ◽  
Practical Applications ◽  
Nano Crystal

There are numerous examples of animals or plants that synthesize extracellular high-performance skeletal biocomposites consisting of a matrix reinforced by nano sized crystalline domains. Cellulose and chitin are classical examples of these reinforcing elements, which occur as whisker-like microfibrils that are biosynthesized and deposited in a continuous fashion. In many cases, this mode of biogenesis leads to crystalline microfibrils that are almost defect-free, and whose axial physical properties therefore approach those of perfect crystals. During the last decade we have attempted to mimic biocomposites by blending cellulose or chitin whiskers from different sources with polymer matrices. Aqueous suspensions of such nano crystals can be prepared by acid hydrolysis of the substrate. The object of this treatment is to dissolve away regions of low lateral order so that the water-insoluble, highly crystalline residue may be converted into a stable suspensoid by subsequent vigorous mechanical shearing action. The resulting nano crystals occur as rod-like particles or whiskers, whose dimensions depend on the nature of the substrate. They are typically a few hundred nm long and between 5 and 20 nm in diameter. Starch can also be used as a source for the production of nano crystals. The constitutive nano crystals appear as platelet-like nano particles with a length ranging between 20 and 40 nm, a width ranging between 15 and 30 nm, and a thickness ranging between 5 and 7 nm. Since the first announcement of using cellulose whiskers as a reinforcing phase, they have been used extensively as model fillers in several kinds of polymeric matrices, including synthetic and natural ones. Casting mixtures of polysaccharide nano crystals and lattices led to the production of nano composite materials with drastically enhanced mechanical properties, especially at T > Tg of the matrix, by virtue of the formation of a whiskers network, even when the whisker volume fraction was only a few percent. The formation of this rigid network, resulting from strong interactions between whiskers, was assumed to be governed by a percolation mechanism. This hydrogen-bonded network induced a thermal stabilization of the composite up to 500 K, the temperature at which polysaccharides start to decompose. Any factors that perturb the formation of this percolating network directly affect the reinforcing effect of polysaccharide nano crystals. In addition to some practical applications, the study of these nano composite materials can help researchers understand such physical properties as the geometric and mechanical percolation effect.Key words: nano composites, polysaccharide, polymer, cellulose, nano crystal.

Evolution of thermo-physical properties of diamond/Cu composite materials under thermal shock load

Rare Metals ◽  
2014 ◽  
Vol 33 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Hong Guo ◽  
Zhi-Hui Bai ◽  
Xi-Min Zhang ◽  
Fa-Zhang Yin ◽  
Cheng-Chang Jia ◽  
...  
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Thermal Shock ◽  
Shock Load ◽  
Thermo Physical Properties

Advances of Study on the Developments and Physical Properties of Composite Materials

2014 ◽  
Vol 633-634 ◽  
pp. 379-382
Author(s):  
A Ying Zhang ◽  
Cai Yun Li
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Chemical Properties ◽  
Composition Materials ◽  
New Material ◽  
The Individual

Composite materials (also called composition materials or shortened to composites) are materials made from two or more constituent materials with significantly different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure. The new material may be preferred for many reasons: common examples include materials which are stronger, lighter or less expensive when compared to traditional materials. Composite materials are generally used for buildings, bridges and structures. The most advanced examples perform routinely on spacecraft in demanding environments.

scholarly journals Sound absorbing and insulating properties of natural fiber hybrid composites using sugarcane bagasse and bamboo charcoal

2021 ◽  
Vol 16 ◽  
pp. 155892502110448
Author(s):  
Santhanam Sakthivel ◽  
Selvaraj Senthil Kumar ◽  
Eshetu Solomon ◽  
Gedamnesh Getahun ◽  
Yohaness Admassu ◽  
...  
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Sugarcane Bagasse ◽  
Sound Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Acoustic Properties ◽  
Sound Insulation ◽  
Bamboo Charcoal ◽  
Green Composite

This research paper reports a study on thermal and sound insulation samples developed from sugarcane bagasse and bamboo charcoal for automotive industry applications. The sugarcane bagasse and bamboo charcoal fiber is a potential source of raw material that can be considered for thermal and sound insulation applications. Natural fibers are commonly used in diverse applications and one of the most important applications is sound absorption. Natural fiber hybrid composite currently is in greater demand in industries because of their advantages such as low cost, biodegradability, acceptable physical properties, and so on. Eco-friendly sound-absorbing composite materials have been developed using bamboo charcoal and sugarcane bagasse fibers. From these fibers five types of natural fiber green composite were developed using the compression bonding technique. The natural composite noise control performance contributes to its wider adoption as sound absorbers. The sound absorption coefficient was measured according to ASTM E 1050 by the Impedance tube method. The physical properties of natural fiber composites such as thickness, density, porosity, air permeability, and thermal conductivity were analyzed for all samples in accordance with ASTM Standard. The result exposed that natural fiber green composite were absorbing the sound resistance of more than 70% and the natural fibers composites provide the best acoustic absorption properties, these composite materials have adequate moisture resistance at high humidity conditions without affecting the insulation and acoustic properties.

Sign in / Sign up

Export Citation Format

Share Document