Abstract: Aluminummatrixcomposites (AMCs) demonstrating a good combination of properties that are hard to acquire by a monolithic aluminum material. Since the last few decades, investigators have shown their keen interest to advance these materials for complex applications. Homogeneous reinforcement distribution, defect-free microstructure, and improved resultant properties depends on the fabrication method along with matrix and reinforcement materials and size. Two-step melt stirring technique and K2TiF6 flux enhanced the wettability and improve the particle distribution of boron carbide (B4C) in AMCs. The mechanical properties of the AMCs were enriched by either extrusion process or thermal treatment. Hybrid composites exhibited better characteristics than mono composites. Surface composites manufactured by incorporation of reinforcement in the surface layer; offer good surface properties without losing toughness and ductility. The B4C-Al interfacial reactions produce different precipitates in AMCs and damaged the composite's age-hardening ability. B4C reinforced friction stir processed surface composites exhibits refined structure and better properties compared to the aluminummatrix. The strength, hardness, and wear resistance of AMCs increased with rising fraction and reducing the size of B4C up to a certain level. Wear rate increases with rising applied load, sliding time and speed. A review of effect of B4C reinforcement on different properties of mono and hybrid AMCs with summarized results attained and concluded by different investigators is presented in this paper to help researchers in the field. At the end of this paper a position given to conclusions and future directions.
strength of nanostructured AA2024 composites increased with increasing SiC content . Sharma et. al. (2015) examined the production of aluminum (AA6082-T6) matrixcomposites reinforced with the various weight percentages of silicon nitride particles by conventional stir casting route. The mechanical properties such as ultimate tensile strength and hardness improved at the cost of the reduction in ductility with the increase in weight percentage of silicon nitride particulates (varying 0 to 12wt.%) in the aluminum metal matrix . Kumar et al. (2015) fabricated aluminummatrixcomposites (AA2618) reinforced by AlN, Si 3 N 4 and ZrB 2 particles (0, 2, 4, 6,
In recent years the use of Ceramic Reinforced Aluminummatrix composite material has increased very rapidly due to their high weight to strength ratio, low density, low thermal expansion coefficient, low maintenance and high temperature resistance. Metal MatrixComposites are widely used in aerospace and automotive engine components. The aluminum alloys are reinforced with ceramics like Alumina, Boron Carbide and Titanium Carbideetc and fabricated by stir casting,spray deposition, powder metallurgyprocedures etc. Heat treatment significantly affects the microstructure and enhances mechanical properties of these composites.In this paper the various research studies on heat treatment of aluminummatrixcomposites is reviewed with major focus on the heat treatment procedures, parameters ,microstructure and mechanical properties. The scope for further research in this area is also discussed. Keywords:Aluminum MatrixComposites,Heat Treatment, T4, T6, Solution heat treatment,Quenching, Age hardening, Microstructure, MechanicalProperties.
In the present technology majority of ductile metal matrix phases are reinforced with high strength, high modulus and often brittle in the form of fiber, particulate, whiskers reinforcement materials. The reinforced MMCs offer opportunities for sufficient improvement in efficiency, reliability and mechanical performance over traditional base metals. In particular, the particulate reinforced metal matrixcomposites are attractive because they exhibit near isotropic properties compared to continuously reinforced counter parts and are easier to process using standard metallurgical methods. Particulate reinforced MMCs provide additional advantage of being machinable. Presently, the main focus is given on Aluminummatrixcomposites because of its unique combination of good corrosion resistance, low electrical resistance and excellent mechanical properties.
remarkable discrepancy of Young’s modulus between ex- perimental data and ROM expression indicating that ROM expression is not ﬁtted very well to predict the Young’s modulus values of discontinuously reinforced aluminummatrixcomposites, same results were obtained by other researchers. 18) In order to make the modulus of discontinu- ously reinforced aluminummatrixcomposites to be predicted well with models, Halpin-Tsai equation was usually adopt- ed: 18)
The experimental procedure and sintering conditions were studied in our previous study . In summaries, Al-GNPs composites were fabricated by PM method as given in Figure 2. In this method, aluminum powders were blended in an ethanol medium using a mixer. Dispersion of GNPs (0.1, 0.3, 0.5wt.%) was carried out for 1 hour using ultrasonic homogenizer. GNPs slurry added drop by drop into the aluminum-ethanol mixture. Mixing performed until homogeneous slurry obtained. After the mixture filtered and dried overnight at 50°C under vacuum. The composite powder was pressed in a mold under 600MPa to form green cylindrical samples. After compacting, the samples were sintered under vacuum in the tube furnace at the constant sintering time and temperature (t S = 180 min and T S =630°C).
Because aluminum-based composites are low cost, light- weight and have superior thermal and electrical properties, proper strength and elongation, they have been used for auto- mobile, aerospace, transportation equipment, etc. Nowadays, high-thermal-conductivity heat-sink for the power semicon- ductor is demanded. Silicon-carbide particle is one of candi- dates as a reinforcing material because it exhibits high elastic modulus and hardness, high melting point and good thermal stability 1–3) . The interfacial thermal resistance between the
Aluminum ingots (99.9% purity) or A2218 alloy bars (pro- duced by Dooray Air Metal Co., Ltd.) of 1 kg placed in a clay-graphite crucible with argon flux cover were heated by a high frequency induction furnace. The crucible with the molten aluminum was taken out from the chamber in the high frequency induction furnace, and was put into the chamber under the plasma spraying nozzle. As the spray processing began, the electromagnetic stirring equipment was switched on to distribute particles homogeneously in the molten alu- minum. After the injection of iron particles reached a re- quired value, the melt was poured into a steel mould with 85 mm in diameter. The main processing variables such as plasma spraying conditions and the temperature of the melt are summarized in Table 1. The Fe powder used in the exper- iment was 99.9% purity and its mean particle size was about 90 µm. The chemical compositions of the A2218 matrix alloy and as-cast A2218/Al 3 Fe composites are given in Table 2.
ABSTRACT:The industrial waste such as fly ash and bagasse ash are most promising alternative reinforcement material for the metal matrixcomposites. Also alumina reinforcement is used commercially for various automotive applications .The present work is focused on the manufacturing of aluminummatrixcomposites (AMCs) by powder metallurgy technique. These reinforcement materials are reinforced with pure aluminium in a 5%, 10% and 15% by weight percentage in between that use ethanol as a binder. After preparation of homogeneous mixture compaction is carried out on universal testing machine. The sintering is carried out in muffle furnace at 630 0 C for the period of 2 hr. The specimens were allowed to cool at normal atmosphere inside the muffle furnace. After complete preparation of specimen by powder metallurgy technique, specimens were tested to identify the lateral compressive strength of the AMCs. It is observed that due to addition of industrial waste in pure aluminium lateral compressive strength of material increases with increase in percentage reinforcement. This study will useful in material that plays vital role in the light weight application such as aerospace, automobile and sporting industries.
Tungsten carbide reinforced aluminummatrixcomposites have attracted considerable attention in recent years because of their potential to exhibit enhanced mechanical properties . However- the effect of Nano WC particles and process parameters on the integrity of hardness and wear resistance of this composite have not reported yet.
Metal matrixcomposites of aluminium, magnesium, titanium and the intermetallic titanium aluminide are highly in demand because of their low density while having significantly high mechanical and thermal properties such as hardness, formability, fatigue life, thermal shock and high-temperature tolerance . Researchers are interested in aluminium or magnesium based MMCs due to their lightweight properties and high stiffness [34-36]. Titanium matrixcomposites (TMC) reinforced with silicon carbide fibers has also found a great application in aerospace industries, mostly in turbine engines. TMCs demonstrate a high performance to weight ratio . Aluminummatrixcomposites (AMCs) are the most widely used type of MMCs in aerospace, and has extensively studied. However, aluminum shows the drawbacks of corrosion and fatigue cracks . Among aluminium alloys, Al6061 is one of the aluminium alloys used for aerospace industry. It has been reported that CNTs is a proper reinforcement of AMCs especially for Al6061  while for Al6082, it is shown that adding graphite particles is not beneficial because it does not show a uniform microstructure and also the hardness reduces . Metal composites of Al2080 Al alloy were studied by Koli et al.  to determine that decrease in SiC particles size increases the fatigue life of the alloy. Besides it is shown that for AA6061-Al 2 O 3 and AA6063-SiC, hardness increases with
The incorporation of reinforcement materials in an aluminum alloy increases the load bearing capacity. The investigation of wear behaviour of AluminumMatrixComposites (AMCs) against friction materials is receiving particular attention because of the possibility of using these materials for disc brakes in automotive application . The addition of reinforcement in an aluminium matrix increases the load bearing capacity and higher wear resistance. The role of SiC+Al 2 O 3 reinforcement has proved to be
have developed for aluminummatrixcomposites. Metal matrixcomposites have generally produced, either by liquid metallurgy or powder metallurgy route. Of these processes, forging is of high technical and economic in- terest because it avoids problems such as the need for special tools (expensive diamond-tipped inserts) during machining, poor mechanical properties because of reac- tions between some ceramic reinforcements and molten metal in casting, and the porosity in P/M components. In the liquid metallurgy, the particulate phases have me- chanically dispersed in the liquid before solidification of the melt. Among others, however, the powder metallurgy (P/M) method has known as a very promising route, which is most attractive due to several reasons. Firstly, in P/M technique microstructural control of the phases is possible (Figure 1). Secondly, the lower temperatures employed during the process accounts for the strict con- trol of interphase kinetics. In the P/M method, the start- ing powders can be elemental or prealloyed. However, it is difficult to take advantage of both these requirements because they are prone to cause an inhomogeneous dis- tribution. Poor distribution of reinforcement degrades the composites in terms of its physical and mechanical prop- erties and negates the attractiveness of reinforcement additions. Using elemental powders are not only eco- nomical, but also bring an extra advantage to modify the matrix composition easily [14-17]. The presence of SiC particles accelerated the aging process due to the in- creased dislocation density, which provides more sites for the nucleation of precipitates. Metal matrix compos- ites reinforced by ceramic particles, with low density, high strength and modulus and flexible fabricating tech- niques, have received particular attention in the past decades. Meanwhile, the particular preparation tech- niques of the composites rely on these factors [18-20]. Fracture of the matrix between the clusters of reinforcing particles, coupled with particle failure by cracking and
A decent amount of research is under progress for finding a suitable material for replacement of the conventional materials used. Due to the need of having less mass in modern day applications, Aluminum metal matrixcomposites are under development to meet specific conditions and get the desired results. Aluminum LM26 alloy can be utilized in place of the conventional Aluminum alloys for certain applications if the proper reinforcements are applied to it.
The advanced composite processes are discussed in more detail in description process. Seven manufacturing processes are covered, along with two preliminary processes and two finishing processes. The number and variety of processes should give some indication of the wide spectrum of workplaces likely to be encountered by field personnel. Potential worker exposure obviously will also vary widely, depending on the size and type of process being used. Since the advanced composite industry is relatively new and still developing, other processes may be developing or changing to meet new performance requirements. Advanced composites exhibit desirable physical and chemical properties that include light weight coupled with high stiffness and strength along the direction of the reinforcing fiber, dimensional stability, temperature and chemical resistance, flex performance, and relatively easy processing. Advanced composites are replacing metal components in many uses, particularly in the aerospace industry .
Magnesium alloys have been increasingly grown in research community in recent years due to the extending areas of their applications. For the lightness and recyclability of magnesium alloys, researches have been done to explore the potential of magnesium and its alloy as s substitute of steel, aluminum and plastic in automotive industry. With the development of scientific and technological process, automobiles become more humanized. More and more electrical devices are installed in vehicles, for example, increasing size of Light-emitting Diode (LED) screen, satellite navigation system (GPS) and rear view camera etc. Obviously, the curb weight is increasing without substitute the materials. Reducing the automobile weight is critical in order to minimize fuel consumption and emission.
Al and Al alloy based composites have been characteristics as futuristic materials for a number of engineering purposes. And the material are more preferred by engineers because of their great strength, low density, enhanced and tailored high refractoriness properties, stiffness and damping capabilities. The principle advantage is that MMCs can be use to a significantly higher temperature. Increasing quantities metal matrixcomposites MMCs being used to replace conventional materials in numerous applications, especially in the automobile and recreational industries. MMC's provide a better combination of Specific strength and modulus compared to monolithic alloys like aluminum, magnesium, copper, nickel and steel in relevance, commonly light weight and energy savings are essential design considerations. In recent years there was a great deal of interest in particulate- reinforced metal-matrixcomposites (MMCs), and in particular those based on existing aluminum alloys.
Many articles show that Nano structure composites can range very high hardness values due to the mixture of a Nano structure phase of a hard compound (typically titanium) inside an amorphous matrix. In D. Mart í nez- Mart í nez’s  study, the microstructure and chemical structure of the coatings were investigated by transmit- ting electron k. microscopy, nuclear force microscopy (AFM), electron diffraction, X-ray diffraction, X-ray photoelectron spectroscopy and electron energy loss spectroscopy. They noticed, for an unadulterated Argon climate, a microstructure constituted by little grains (10 - 20 nm) of a TiC stage embodied into an undefined framework. AFM parallel force mapping demonstrates a strong frictional difference between the two stages. At the point when nitrogen is used in the gas stage of the preparation process, the granular microstructure is not no- ticed, whereas the chemical composition is enriched in undefined nonstoichiometric CNx phases (a-CNx) with diverse content of nitrogen (0.5V × V0.7). They related the kind of structure and chemical bonding of the Ti-C-N films with the tribological properties at the minuscule level so as to set up the amalgamation conditions prompting the nanocomposite construction.
A. Ourdjini, K.C. Chew, B.T. Khoo et. al.  Isothermal holding of A356 Al alloy reinforced with 20 wt. % of SiC And examination on microstructure for settling of particles during liquid processing of composite. and get in results, settling measurements during isothermal holding show that the SiC particles settle at much lower rates than predicted by isothermal model. Qualitative examination of the settling phenomenon shows that composites reinforced with low volume fraction of particles tend to settle faster particularly if the melt temp is high.