**4.3 Metal matrix composites**

Metal-based matrixes/composites are obtained through ductile metal particulate fortification via continuous and discontinuous or whisker fiber molds. Reinforced composites appear as green/benign materials owing to special features like precise rigidity, nonflammability, high stability, abrasion/creep resistance and thermal/electrical conductivity besides sustainability at serviceable temperature and pressure than their counterparts [15]. But metal matrix composites are much more expensive than other reinforced composites, so they possess limited utility. Superalloys and alloys of metals are engaged in making such metal-based matrixes/composites [15, 16]. Continuous fiber moldings utilize assorted organic and inorganic fibers like carbon, silicon carbide, boron, aluminum oxide and certain refractory metals, while discontinuous path of reinforcements involves fibers of silicon carbide, aluminum oxide, silicon oxide and carbon [17]. Metal matrix composite yield via dispersion of reinforced fabric in metallic template and reinforced surfaces gets coating to avoid auto-oxidation. The template is made

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polyoxymethylene, polypropylene, vinyl ester,

acrylonitrile butadiene styrene, high-density

Inorganic materials Semicrystalline thermoplastics, UP Isotropic contraction, graze,

Microsphere Glass micro-/mesospheres Less weight, solid fillers

**Constituting components Superior features**

polyepoxide, polyester, vinyl ester, polyacrylate Suppleness, high tensile

Strengthen expansion coefficient, own great electric and heat resistance

strength and solidity, electrical strengthen

high solidity potential

surface characters

Flexible strength, alternative

strength

Flexural potency, high tensile modulus and strength

up of monolithic material wherein the reinforced fiber gets embedded through continuous moldings. Highly structured metal matrix/composite is derived through aluminum, magnesium or titanium metallic supports for reinforcement with fibers. The reinforced fiber can be embedded into metallic skeletons achieving either constant or irregular structural tasking, which can modify certain physicochemical features, viz. wear/shear resistance, friction coefficient, and thermal and

Metal composite is reinforced through continuous or discontinuous mode of fabrications, viz. extrusion, forging and rolling so as to get isotropic matrix besides usual polycrystalline diamond tooling. Continuous reinforced technique embeds monofilament wire/fiber of boron, carbon and silicon carbide in assured path and yields anisotropic arrayed metal composite, while discontinuous reinforced technique uses fuzzy short fiber/particles of alumina and silicon carbide. The high temperature treatments are needed in fabrication of metal involved matrixes developments in order to obtain the best dispersion of constituting fiber skeletal interfaces (as on cooling yields residual strain amongst metal and reinforced fibers being vital for best composite formations [4–6]. This controlling residual stresses notably manipulates mechanical instincts of fabricated metal composites. Many metal matrix/composite have two constituents: one as metal and the other may/may not be metal or may be ceramic and/or organics. If three or more metals are used, the resultant matrix is termed as hybrid. Such metal-based matrixes/composites are complementary to heat-resistant materials like ceramic and sintered metal. Hybrid composites are innovative fiber-reinforced matrix acquired through mixing of two/ more fibers imparting improved features than other composites. Reinforcement of polymeric resin with pretty firm and low-density materials like carbon and glass fibers yields sturdy/tougher composites besides superior resistive plastic hybrid composites [15]. Certain hybrids/composites found to possess aligned and thoroughly amalgamated fiber layer besides mutually alternated depositions impart anisotropic properties owing to finally harmonize template phases. Some hybrid composites are foremost in their typical applicability in constructing lightweight structural units, orthopedic components, sturdy transporting templates used in aerospace, marine

*DOI: http://dx.doi.org/10.5772/intechopen.91305*

Glass-based fiber Epoxide, polyamide, polycarbonate,

polybutylene terephthalate

Wood-based fiber Polyethylene, polylactic acid, polypropylene,

polyethylene

Chitosan Metals, nonmetals, synthetic and natural polymers

*Various reinforced composites with superior applicable features [13].*

**Reinforced matrix/ composite**

Carbon- and aramidbased fiber

**Table 1.**

electrical conductivity [18].

*Reinforce Fabricated Nano-Composite Matrixes for Modernization of S & T in New Millennium DOI: http://dx.doi.org/10.5772/intechopen.91305*


#### **Table 1.**

*Composite and Nanocomposite Materials - From Knowledge to Industrial Applications*

exploited to get specific/rationally designed products like thermoplastic at quite a cheap cost. Such carbon-reinforced composites have huge strength:weight ratio and rigidity as needed in aerospace, transportation superstructures, automotive, engineered products, scaffolds and smart equipment. Certain fiber-reinforced plastic/composites are fabricated through polymeric matrix like organic/inorganic fibers, paper, wood and asbestos, which caters to the needs of aerospace, automotive, marine and constructions besides ballistic armor. American Chemist Leo Hendrik Baekeland in 1905 had replaced shellac-resin (yield from lac bug's excretion) with synthetic Bakelite polymer obtained via phenol-formaldehyde reaction at controlled pressure and temperature, and it was the world's first synthetic plastic that was fiber-reinforced [14]. In 1936, du-Pont obtained resin-composite through "*fiber-glass*" blending with plastic followed by modern *cyanamids* resin in 1942. Glass, carbon and aramid fibers are still used in making fiber-reinforced plastic/ composites. Certain polymer-reinforced combinations are stated in **Table 1**.

*Assorted orientations in fibrous reinforced composites [1, 2, 13].*

Metal-based matrixes/composites are obtained through ductile metal particulate fortification via continuous and discontinuous or whisker fiber molds. Reinforced composites appear as green/benign materials owing to special features like precise rigidity, nonflammability, high stability, abrasion/creep resistance and thermal/electrical conductivity besides sustainability at serviceable temperature and pressure than their counterparts [15]. But metal matrix composites are much more expensive than other reinforced composites, so they possess limited utility. Superalloys and alloys of metals are engaged in making such metal-based matrixes/composites [15, 16]. Continuous fiber moldings utilize assorted organic and inorganic fibers like carbon, silicon carbide, boron, aluminum oxide and certain refractory metals, while discontinuous path of reinforcements involves fibers of silicon carbide, aluminum oxide, silicon oxide and carbon [17]. Metal matrix composite yield via dispersion of reinforced fabric in metallic template and reinforced surfaces gets coating to avoid auto-oxidation. The template is made

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**4.3 Metal matrix composites**

**Figure 2.**

*Various reinforced composites with superior applicable features [13].*

up of monolithic material wherein the reinforced fiber gets embedded through continuous moldings. Highly structured metal matrix/composite is derived through aluminum, magnesium or titanium metallic supports for reinforcement with fibers. The reinforced fiber can be embedded into metallic skeletons achieving either constant or irregular structural tasking, which can modify certain physicochemical features, viz. wear/shear resistance, friction coefficient, and thermal and electrical conductivity [18].

Metal composite is reinforced through continuous or discontinuous mode of fabrications, viz. extrusion, forging and rolling so as to get isotropic matrix besides usual polycrystalline diamond tooling. Continuous reinforced technique embeds monofilament wire/fiber of boron, carbon and silicon carbide in assured path and yields anisotropic arrayed metal composite, while discontinuous reinforced technique uses fuzzy short fiber/particles of alumina and silicon carbide. The high temperature treatments are needed in fabrication of metal involved matrixes developments in order to obtain the best dispersion of constituting fiber skeletal interfaces (as on cooling yields residual strain amongst metal and reinforced fibers being vital for best composite formations [4–6]. This controlling residual stresses notably manipulates mechanical instincts of fabricated metal composites. Many metal matrix/composite have two constituents: one as metal and the other may/may not be metal or may be ceramic and/or organics. If three or more metals are used, the resultant matrix is termed as hybrid. Such metal-based matrixes/composites are complementary to heat-resistant materials like ceramic and sintered metal. Hybrid composites are innovative fiber-reinforced matrix acquired through mixing of two/ more fibers imparting improved features than other composites. Reinforcement of polymeric resin with pretty firm and low-density materials like carbon and glass fibers yields sturdy/tougher composites besides superior resistive plastic hybrid composites [15]. Certain hybrids/composites found to possess aligned and thoroughly amalgamated fiber layer besides mutually alternated depositions impart anisotropic properties owing to finally harmonize template phases. Some hybrid composites are foremost in their typical applicability in constructing lightweight structural units, orthopedic components, sturdy transporting templates used in aerospace, marine

goods, sport items and trivial stuff infrastructures in building constructions [15–18]. Lightweight military aircrafts and helicopters are made with such rationally designed hybrid composites offering 20–40% reduced weights than contemporary materials. Glass fiber-reinforced carbon fiber yields hybrids/composites to be used to make rotor blades of helicopters due to innate superior fatigue resistivity as needed in making futuristic hypersonic fighter planes and aircrafts [1, 19].

## **4.4 Structural composites**

Structural composites are obtained through geometrically designed structural elements in homogeneous pattern derived through constituents. Laminar and sandwich plates come under the category of structural composites. The strength properties of advanced structural composites offer broad mechanical properties as controlled by many parameters like volume/weight proportions of reinforced fiber/ matrix components, built-up formulations, constituent mechanical features and orientations via uni- or bidirectional, besides various off-axis directional/random, arrangement. Sandwich panels are designed as lightweight structural composites owing to their comparatively elevated mechanical strengths. Such sandwich configured composites are very unique as fabricated via attachment of two thin and rigid skins to yield lightweight but bulky core slotted panel own duel outer face of relatively stiff and strong template like metal alloy, fiber-reinforced plastics, steel, and plywood adhesively bonds to thicker light-mass inner hub materials. Sandwich panels consist of inner core material made up of lightweight and low elasticity modulus like polymeric skeleton phenolics, epoxy, polyurethanes, wood and honeycombs [15, 20], while outer sheets in sandwich panels consist of tough/rigid materials so as to communicate high mechanical strength under high tensile/compressive strain loading. Sandwich panels-based structural composites offer wide utilities including in buildings' roofs, floors and walls, besides being used in fabrication of wings, fuselage and tail plane skins of aerospace and aircrafts [21–23].

#### **4.5 Laminar composites**

Some laminar composites yield through single layer fiber laminated mutual bonding or stacking own accordingly paved orientations of latent directional fluctuations achieved via consecutive depositions. The particulate platelet or laminar matrixes possess two long dimensions, e.g., wooden thin layer plywood with consecutive layers that are quite isotropic composites due to dissimilar grain/ fiber orientations that are weaker in any direction than it would be if constituting fibers could all be aligned in one direction [1]. Layers of assorted fiber reinforcement yield hybrid laminate revealing anisotropic and directional structures. Based on stacking order of each layers, laminated composites owing to their in-plane and out-plane bend-stretch coupling ultimately give in-plane loading. In fact, laminar composite has two-dimensional panels or sheets with favored directions to attain highest strength [6–8]. Wood and plywood material is basically a laminated composite holding constant reinforced and preferred directional stack layer of fiber orientation instead of adhesive joints. Such laminated composite layering fetches each grain at 90° angle with its neighbors. Laminated composite attains superior mechanical strength, stability and appearance as assembled via heat, pressure and adhesive treatments. Assorted laminated composites are obtained, depending on constituents and the processing applied in their manufacturing [1–4, 6–12, 14, 15, 24]. Certain plastic-laminated glassy-type composites behold tight fit adhesiveness at their solid countertop surfaces, which were found to protect the particleboard. Cellulosic templates appear good substrates for assorted matrixes as obtained

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through overlay thermo-processing, e.g., laminated composite panels, medium density fiber-boards, decorative foils, high-pressure decorative composites, wood/ multi-laminar veneer and resin-saturated decorative papers. Recently, numerous layer-wise dimensionally organized products like special glue/laminated timber composites are developed owing to mutual lumber bonding viable for durability, water-resistance and structural adhesiveness in resultant products, e.g., glulam a versatile stress-engineered wood beam composed of special laminations [1].

Environmental causes urge to develop green composites based on renewable sources like biopolymers as economic options for glass/carbon fiber-derived composites [25]. Thus, plant-, jute- and sugar cane-based lignocellulosic composite-derived matrixes can serve this purpose. Fabrication of organic-based nanocomposites arose as a multidisciplinary area in advanced nanotechnology, particularly procured through sustainable and eco-friendly resources and methods. Some green composites are also obtained via reframing natural/bio-polymeric framework via amalgamating other natural/synthetic material substrates that offer morphological/interfacial design characteristics in resultant products over conventional counterparts [26]. Assorted biopolymeric skeletons, viz. starch, alginate, dextran, carrageenan, chitosan and cellulose, are formulated/envisaged due to their innate functional features like nontoxicity, biodegradability and biocompatibility [2, 3]. Natural lignocellulosic fibers have semicrystalline cellulose microfibril orientation offering multifunctional nanotechnological fabrications so as to cater to advanced

Cellulose is an extensively copious natural polymer and component of the "plant's skeleton" that exists on Mother Earth [1]. In fact, cellulose shares the same chemistry and molecular structures but imperative morphology and mechanical variations based on its recovery from various sources like vegetable, plants and bacteria. Nanocomposite matrixes are derived through cellulose skeleton via amalgamation with different phases of organic and inorganic materials [1, 13]. Nanofibrillated and bacteria-derived cellulose is made up of nanodimensional fibers, which impart novel and improved native qualities in resultant nanocomposites than vegetable-derived cellulose [13, 27]. Cellulose has soft matrix to accommodate inorganic/organic materials via blending diverse fillers to yield composites owing to their inherent functionality of constituents besides transporting unique functions due to biointerfacial alteration [7, 27]. Various material like nano-metals including gold silver and copper and inorganic gets easily doped/ filled in the cellulose skeleton and yield composites which own altered fibers interaction at surfaces over bulk analogues besides coalition of fillers is beneficial for improvement of opto-electronic/electrical and mechanical functions [1, 2]. Cellulose has an exclusive arrangement and discrete affinity to form intra-/ intermolecular bonding, which compacts its supramolecular ester/acetate and ether as dynamic derivatives utilized in coating, pharmaceutics, food and cosmetic industries [12, 27]. Hybrids of cellulose procured through nanometal/metal-oxides yield assorted nanocomposites like *Nowa-74* used as calorie-free dessert in food and wound dressing scaffolds in biomedical and optoelectronics. Water filtering nanomembranes are reinforced through 3D cellulose matrix owing to its brilliant characters like high purity, high polymerization degree, elevated crystallinity, high elasticity and mechanical stability and huge surface area. Certain physicochemical

*DOI: http://dx.doi.org/10.5772/intechopen.91305*

**4.6 Lignocellulosic composites**

applications in S&T as mentioned below:

**4.7 Cellulose-derived nanometal matrixes**

through overlay thermo-processing, e.g., laminated composite panels, medium density fiber-boards, decorative foils, high-pressure decorative composites, wood/ multi-laminar veneer and resin-saturated decorative papers. Recently, numerous layer-wise dimensionally organized products like special glue/laminated timber composites are developed owing to mutual lumber bonding viable for durability, water-resistance and structural adhesiveness in resultant products, e.g., glulam a versatile stress-engineered wood beam composed of special laminations [1].
