Metal matrix composites fabrication

Jeng-Maw Chiou, Chung DDL, Characterization of metal-matrix composites fabricated by vacuum infiltration of a liquid metal under an inert gas pressure, J Mater Sci, 26, 2583-2589, 1991. 

There are several important fabrication processes for metal-matrix composites. 

Applied Sciences, Inc. has, in the past few years, used the fixed catalyst fiber to fabricate and analyze VGCF-reinforced composites which could be candidate materials for thermal management substrates in high density, high power electronic devices and space power system radiator fins and high performance applications such as plasma facing components in experimental nuclear fusion reactors. These composites include carbon/carbon (CC) composites, polymer matrix composites, and metal matrix composites (MMC). Measurements have been made of thermal conductivity, coefficient of thermal expansion (CTE), tensile strength, and tensile modulus. Representative results are described below. 

Ceramic matrix composites are produced by one of several methods. Short fibers and whiskers can be mixed with a ceramic powder before the body is sintered. Long fibers and yams can be impregiated with a slurry of ceramic particles and, after drying, be sintered. Metals (e.g., aluminum, magnesium, and titanium) are frequently used as matrixes for ceramic composites as well. Ceramic metal-matrix composites are fabricated by infiltrating arrays of fibers with molten metal so that a chemical reaction between the fiber and the metal can take place in a thin layer surrounding the fiber. 

Short-fiber composites fabrication of, 26 766 Short fiber metal-matrix composites, casting process for, 76 168 Short fiber web layering systems, 77 504 Short oil alkyds, 2.T48 Short random fiber reinforcement,... 

Morel, M., Saravanos, A. and Chamis, C.C. (1991). Interphase layer optimization for metal matrix composites with fabrication consideration. NASA TM-105166. 

Deposition of a nickel layer hy fluidized bed CVD can improve sintering in powder metallurgy applications. The process can he used as a premixing step of the composite, for example on W particles. A similar technique can also he used to improve the wettabilty of ceramics like SiC hy the molten A1 during the fabrication of metal matrix composites. ... 

Choi, Y, Mullins, M. E., Wijayatilleke, K and Lee, J. K., Fabrication of metal matrix composites of TiC-Al through self-propagating synthesis reaction. Metall. Trans. A, 23A, 2387 (1992). 

In recent years, there has been a growing interest in the electrochemical synthesis of composite materials consisting of metal matrix with embedded particles of oxides, carbides, borides, etc. Metal-matrix composites offer new possibilities in fabrication of ftmctional coatings with radically improved durability and performance [1], However, in spite of the efforts of many researches, the overall picture of the processes occurring during co-deposition of metal with dispersed phase and mechanism of particle-induced modification of mechanical and chemical properties still remain unclear. In this study, we focused on the kinetics and mechanism of the electrochemical co-deposition of nickel with highly dispersed oxide phases of different nature and morphology. 

Fibers that retain their high strength to temperatures in the range 1200-1500°C are needed for use as the reinforcement in ceramic and metal matrix composites. This portion of this chapter deals with the fabrication of SiC fibers using CVD. It is divided into sections on current status, hot- and cold-wall reactor designs, stresses in coated fibers, processing results, and economics. 

The combination of infiltration and reaction that characterizes DMO has been exploited to make a number of composites. As long ago as 1953, it was shown that silica containing refractories were reduced by molten aluminum to form alumina and silicon [4], Subsequently [27], the displacement reaction was extended to the formation of composites of alumina with residual Al-Si. More recently, the Al-Si02 displacement reaction has been used in the infiltration of dense preforms of silica [28] and mullite [29,30] by molten aluminum. Extension of the reactive infiltration process to porous silica-containing preforms [31,32] has resulted in the fabrication of metal-matrix composites in which the silica was replaced by a mixture of about 65% alumina and 35% metal, while the pores were infiltrated by molten alloy. In contrast to DMO, the displacement reaction appears to proceed at a critical temperature of 1100-1200°C and without the need for a volatile solute element or oxygen. Borosilicate glass has also been used as an initiator to enable the infiltration of Al-Si alloys into alumina preforms [33]. 

SiC whisker also can be combined with metals (MMCs, metal matrix composites) to increase the high temperature strength of the material as well as provide a comparable substitution for heavier traditional materials, such as steel. MMCs can be fabricated by infiltrating a SiC whisker preform with aluminum or by addition of SiC whiskers to molten aluminum. 

Silicon Carbide and Oxide Fiber Reinforeed Alumina Matrix Composites Fabricated Via Direeted Metal Oxidation... 

A variety of CMC systems have been developed and fabricated in the past. These have included aluminum oxide, aluminum nitride and sihcon nitride matrix composites [3-5]. The reinforcement has predominantly consisted of silicon carbide based fibers. Oxide based fibers have also been evaluated over the years as and when they have become available. This chapter reviews the development effort of silicon carbide reinforced aluminum oxide matrix composites fabricated via directed metal oxidation and compares them with those reinforced with oxide fibers. 

A.S. Fareed, Ceramic Matrix Composite Fabrication and Processing Directed Metal Oxidation, Handbook on Continuous Fiber Reinforced Ceramic Matrix Composites, ed. R.L. Lehman, S.K. El-Rahaiby Jr and J.B. Wachtman, Jr., ClAC/ACers, 301-324 (1995). 

R. Asthana, Cast metal-matrix composites. I Fabrication techniques, J. Mater. Processing Technology, 5 [4], 251-278 (1997). 

Yih P, Chung DDL, Powder metallurgy fabrication of metal matrix composites using coated fillers, Int J Powder Metall, 31(4), 335-340, 1995. 

Farced, A. S., Schiroky, G. H., and Kennedy, C. R. (1993). Development of BN/SiC duplex fiber coatings for fiber-reinforced aluminia matrix composites fabricated by directed metal oxidation. Ceram. Eng. Sci. Proc. 18 794-801. 

Description and General Properties. Metal matrix composites (MMCs) consist of a metal or an alloy matrix with a reinforcement material (e.g., particulates, monofilaments, or whiskers). The matrix alloy, the reinforcement material, the volume and shape of the reinforcement, the location of the reinforcement, and the fabrication method can all be varied to achieve required properties. Most of the metal-matrix composites are made of an aluminum matrix. But aluminum-matrix composites must not be considered as a single material but as a family of materials whose stiffness, strength, density, and thermal and electrical properties can be tailored. Moreover a growing number of applications require improved matrix properties and therefore, metal matrices of magnesium, titanium, superalloys, copper, or even iron are now available commercially. Compared to bulk metals and their alloys, MMCs offer a number of advantages such as ... 

Cui, C., Shen, Y. Meng, F. (2000). Review of Fabrication Methods of In Situ Metal Matrix Composites. Journal of Materials Science and Technology, Vol. 16, No. 6, pp. 619-642, ISSN 10050302... 

Metal matrix composite (MMC) particles can be fabricated through mixing solid particles and atomized liquid droplets in a spray atomization and co-injection process [4, 5, 30, 31, 52]. The process is characterized by a three-phase spray flow (gas/droplets/ particles). Solid particles (usually at least one order of magnitude smaller than atomized droplets), conveyed by the atomization gas or via a separate gas-assisted delivery system, are injected into the droplet spray and likely to be incorporated into the droplets or captured by the droplets surface during frequent impingements, forming composite droplets which are subsequently solid-ifled as composite particles. 

Zhao-hui, W., Xu-dong, W., Zhaou-xin, W., Wen-bo, D., 2010. SiC nanoparticles reinforced magnesium matrix composites fabricated by ultrasonic method. Transactions of Nonferrous Metals Society of China 20, 1029—1032. 

L. Gai and M. Ziemnicka-Sylwester, The TiBz-based Fe-matrix composites fabricated using elemental powders In one step process by means of SHS combined with pseudo-HlP, IntemationalJoumal of Refractory Metals and Hard Materials, 45,141-146 (2014)... 

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