This article discusses the dies, such as shear-face dies, conical-feed dies, and bridge dies, that are used in extrusion of particle-reinforced aluminum composites. It provides an overview of the effects of reinforcements on the properties of aluminum composites.

In general, metal-matrix composites (MMCs) are classified into three broad categories: continuous fiber-reinforced composites, discontinuous or short fiber-reinforced composites, and particle-reinforced composites. This article focuses on stir casting and melt infiltration as the two main methods of MMC solidification processing. It describes the MCC casting methods, such as sand and permanent mold casting, centrifugal casting, compocasting, and high-pressure die casting. The article discusses the MMC infiltration processes in terms of pressure infiltration casting and liquid metal infiltration. It reviews the powder metallurgy processing of aluminum MMCs and deformation processing of discontinuously reinforced aluminum composites. The article concludes with a discussion on the processing of fiber-reinforced aluminum.

This article describes the characterization techniques, mechanical tests, and nondestructive evaluation methods that are commonly used for metal-matrix composites. It also tabulates typical methods of particle size and size distribution measurement, as well as mechanical test specifications for aluminum-matrix composites.

This article provides a summary of the concepts discussed in the articles under the Section “Post-Processing and Assembly” ASM Handbook, Volume 21: Composites.

This article presents an overview of advanced composites, namely, polymer matrix composites, metal-matrix composites, ceramic-matrix composites, and carbon-matrix composites. It also provides information on the properties and applications of the composites in thermal management and electronic packaging.

Metal-matrix composites (MMCs) are a class of materials with a wide variety of structural, wear, and thermal management applications. This article discusses the primary processing methods used to manufacture discontinuous aluminum MMCs, namely, high-pressure die casting, pressure infiltration casting, liquid metal infiltration, spray deposition, and powder metallurgy methods. It describes the processing of continuous fiber-reinforced aluminum, discontinuously, reinforced titanium, and continuous fiber-reinforced titanium. The article concludes with information on work done to develop magnesium, copper, and superalloy MMCs.

This article begins with the discussion on the background of metal-matrix composites (MMC) and moves into a broad description of the general parameters affecting the corrosion of MMC. It discusses the primary sources of MMC corrosion that include galvanic corrosion between MMC constituents, chemical degradation of interphases and reinforcements, microstructure-influenced corrosion, and processing-induced corrosion. The article elaborates on the corrosion behavior of specific aluminum, magnesium, titanium, copper, stainless steel, lead, depleted uranium, and zinc MMCs systems. It concludes with a description on the corrosion control of MMCs using protective coatings and inhibitors.

Metal matrix composites (MMCs) can be synthesized by vapor phase, liquid phase, or solid phase processes. This article emphasizes the liquid phase processing where solid reinforcements are incorporated in the molten metal or alloy melt that is allowed to solidify to form a composite. It illustrates the three broad categories of MMCs depending on the aspect ratio of the reinforcing phase. The categories include continuous fiber-reinforced composites, discontinuous or short fiber-reinforced composites, and particle-reinforced composites. The article discusses the two main classes of solidification processing of composites, namely, stir casting and melt infiltration. It describes the effects of reinforcement present in the liquid alloy on solidification. The article examines the automotive, space, and electronic packaging applications of MMCs. It concludes with information on the development of select cast MMCs.

This article describes the fatigue properties of particle-reinforced metal-matrix composites (PR-MMCs) in terms of mechanisms of crack initiation, fatigue life, and fatigue crack growth. It reviews specimen preparation and microscopic procedures that are used in fatigue testing of MMCs. It also describes the evaluation of the long fatigue crack growth behavior of MMCs by using the test methods and specimens that are used for unreinforced metallic alloys. Fractography of MMCs under plane-strain conditions is also described with information on the observed features of MMC fatigue fracture surfaces and their observation methods.

This article discusses the solidification of a matrix alloy in cast metal matrix composites (MMCs). It begins with a discussion on the mixing techniques in reinforcement incorporation and wettability of reinforcement. It describes the solidification processes, such as stir mixing and melt infiltration, used in the synthesis of MMCs. The article also considers the fundamentals of the process and presents a computational modeling of particle/solidification front interactions in metal-ceramic systems. The article concludes with information on nanocomposites.

This article focuses on the production of particulate reinforcements that are used in discontinuously reinforced metal-matrix composite (DRMMC) materials systems, their physical and materials properties, and the particle shape and overall morphology. The most common DRMMC materials systems used for aerospace structural applications are silicon carbide and boron carbide particulate reinforcement in an aluminum alloy matrix. The article concludes with information on reinforcement chemistry for designing DRMMC materials systems.

This article focuses on the techniques used in recycling of aluminum metal matrix composites (MMCs) such as discontinuous SiC reinforced aluminum MMCs and continuous reinforced aluminum MMCs. It provides a discussion on the properties of recycled aluminum MMCs and disposal of aluminum MMCs.

Discontinuously reinforced aluminum (DRA) alloy metal-matrix composites (MMCs) represent an advanced aluminum materials concept whereby ceramic particles, or whiskers, are added to aluminum-base alloys through the use of either ingot-melting or casting and/or powder-metallurgy (P/M) techniques. This article begins with a summary of general observations on the forging of discontinuously reinforced composites. It provides information on some of the specific experimental results obtained on various DRA systems, including 2xxx DRA alloys and cast DRA alloys. The article reviews the efforts on the modeling of behavior of specific alloy systems, with a comparison of experimental results to the modeling attempts. It concludes with information on the properties of deformation-processed DRA alloys.

Metal-matrix composites (MMCs) are a class of materials with potential for a wide variety of structural and thermal applications. This article discusses the mechanical properties of MMCs, namely aluminum-matrix composites, titanium-matrix composites, magnesium-matrix composites, copper-matrix composites, superalloy-matrix composites, and intermetallic-matrix composites. It describes the processing methods of discontinuous aluminum MMCs which include casting processes, liquid-metal infiltration, spray deposition and powder metallurgy. The article provides useful information on aluminum MMC designation system and also describes the types of continuous fiber aluminum MMCs, including aluminum/boron MMC, aluminum/silicon carbide MMC, aluminum/graphite MMC, and aluminum/alumina MMC.

Metal-matrix composites (MMCs) are used in structural applications, and in applications requiring wear resistance, thermal management, and weight savings. This article summarizes the mechanical and thermal properties of discontinuously reinforced aluminum MMCs, laminated metallic composites, and continuously aligned fiber reinforced MMCs.

The effective integration of aluminum metal-matrix composites (Al-MMCs) into useful structures and devices often requires an understanding of the weldability of Al-MMCs that includes a thorough knowledge on the effects of various interactions between matrix and reinforcement. This article provides a detailed discussion on weldability and the effect of viscosity, chemical reactions, and solidification on weldability. It discusses different welding processes, namely, gas-tungsten arc welding, gas-metal arc welding, laser-beam welding, electron-beam welding, resistance welding, friction welding, transient liquid phase bonding, and capacitor discharge welding.

Metal-matrix composites (MMCs) are a class of materials with potential for a wide variety of structural and thermal management applications. They are nonflammable, do not outgas in a vacuum, and suffer minimal attack by organic fluids, such as fuels and solvents. This article presents an overview of the status of MMCs, and provides information on physical and mechanical properties, processing methods, distinctive features, and various types of continuously and discontinuously reinforced aluminum, magnesium, titanium, copper, superalloy, and intermetallic-matrix composites. It further discusses the property prediction and processing methods for MMCs.

Aluminum alloys are widely used in engineered components because of their excellent strength-to-weight ratio. Their use in applications requiring wear resistance is more limited. One of the main limitations of aluminum alloys is the poor tribological behavior mainly due to their relatively low hardness, which favors large plastic deformation under sliding conditions. This article discusses the classes and mechanisms of wear in aluminum-silicon alloys, aluminum-tin bearing alloys, and aluminum-matrix composites; describes the effect of material-related parameters on wear behavior of these alloys; and reviews their applications in a variety of tribological applications in the automotive industry ranging from aluminum-tin alloys for plain bearings to alloys with hard anodizing for machine elements. Methods to improve wear resistance and alloy hardness are also discussed.

This article begins by describing the designations of cast and wrought aluminum alloys. It explains the effects of main alloying elements in aluminum alloys: boron, chromium, copper, iron, lithium, magnesium, manganese, nickel, phosphorus, silicon, sodium, strontium, titanium, and zinc. The article describes the microstructure of cast and wrought aluminum alloys and the various strengthening mechanisms, including solid solution, grain refinement, strain or work hardening, precipitation (or age) hardening, and dispersoid strengthening. The article explicates the tribological behavior of aluminum alloys, aluminum-base composites, and metal-matrix composites. It presents the effect of material-related parameters and external factors on wear behavior and transitions of aluminum-silicon alloys. The article also presents the most important factors affecting the dry sliding wear behavior of particle-reinforced aluminum-base composites against a steel counterface.