Search Results for automotive brakes

This article focuses on friction and wear of automotive and aircraft brakes. It provides a comparison of friction and wear behaviors, frictional characteristics, and frictional performance of the friction materials. The article describes the components of brake friction materials and the classifications of brake lining materials. It discusses the effect of formulation compositions and manufacturing processes and the effect of braking operation conditions. The article provides information on aircraft brake linings, which operate under a wide range of kinetic energy conditions. The morphology effect of graphite on automotive brake drum and disk is explained. The article also describes the characteristics of specific wear rates for both normal and local cast iron in automotive brake drums and disk rotors. It provides information on noises, vibrations, and harshness caused by brake pads. The article concludes with information on physical and chemical testing of brakes and toxicity of brake formulation and regulations.

This article highlights the selected applications of advanced polymer-matrix composites, metal-matrix composites, and ceramic matrix composites.

This article describes the physical properties of powder metallurgy (PM) stainless steels. These include thermal diffusivity, conductivity, thermal expansion coefficient, Poisson's ratio, and elastic modulus. The article contains a table that lists the characteristics of various grades of PM stainless steels. It discusses the applications of various PM stainless steels such as rearview mirror brackets, anti-lock brake system sensor rings, and automotive exhaust flanges and sensor bosses.

Metal casting is the manufacturing method in which a metal or an alloy is melted, poured into a mold, and allowed to solidify. Typical uses of castings include municipal hardware, water distribution systems (pipes, pumps, and valves), automotive components (engine blocks, brakes, steering and suspension components, etc.), prosthetics, and gas turbine engine hardware. This introduction explains the steps involved in making a casting using a simplified flow diagram, and discusses the ferrous and nonferrous alloys used for metal casting.

This article provides information on the applications of metal-matrix composites in engine components, brake system, and driveshaft. The components include pistons, cylinder liners, valves, pushrods, and connecting rods.

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.

Cast irons have been widely used by engineers in applications that require low cost, excellent castability, good damping capacity, ease of machining, and wear resistance. This article discusses the classification of wear for cast irons: adhesive wear, abrasive wear, and erosive wear. Typical wear applications for a variety of cast iron grades are listed in a table. The article reviews the general wear characteristics of gray irons, compacted graphite (CG) irons, and ductile irons. It discusses the typical compositions and properties of white and chilled iron castings. Gray cast iron is the dominant material for both brake drums and disk brake rotors. The article reviews brake lining chemistry effects, graphite morphology effects, and external abrasive effects on brake drums. It concludes with information on cast iron grinding balls.

This article presents typical wear applications for a variety of cast iron grades in a table. In general, wear is classified according to three major types: adhesive (frictional) wear (sliding and rolling) caused by contact of one metallic surface with another; abrasive wear caused by contact with metallic (shots, swarf) or nonmetallic abrasive materials; and erosive wear. The article discusses general wear characteristics of gray iron, compacted gray iron, and ductile iron. It provides information on the brake lining chemistry effects, graphite morphology effects, normal cast iron wear, local cast iron wear, and external abrasive effects on brake drums and disk brake rotors made of gray cast iron. The article concludes with a discussion on the application of cast iron for grinding balls.

This article summarizes some general alloy groupings by application or major characteristics. The groupings include cast rotor, general-purpose, elevated-temperature, wear-resistant, moderate-strength, high-strength, and high-integrity die casting alloys and cast aluminum alloys bearings. A table lists selected applications for aluminum casting alloys.

Friction welding (FRW) can be divided into two major process variations: direct-drive or continuous-drive FRW and inertia-drive FRW. This article describes direct-drive FRW variables such as rotational speed, duration of rotation, and axial force and inertia-drive FRW variables such as flywheel mass, rotational speed, and axial force. It lists the advantages and limitations of FRW and provides a brief description on categories of applications of FRW such as batch and jobbing work and mass production. A table of process parameters of direct-drive FRW systems relative to inertia-drive FRW systems is also provided.

Friction materials are the components of a mechanism that converts mechanical energy into heat upon sliding contact. This article discusses the selection criteria, manufacturing process, and applications of friction powder metallurgy materials. It provides information on the manufacturing process of powder metallurgy friction materials through a process of mixing/blending, compacting, and sintering. The final machining that they undergo, to ensure that they meet dimensional specifications, is also discussed.

Compacted graphite iron (CGI) invariably includes some nodular (spheroidal) graphite particles, giving rise to the definition of the microstructure in terms of percent nodularity. This article discusses the graphite morphology and mechanical and physical properties of CGI. The mechanical and physical properties of CGI with ferritic and pearlitic matrix structures are summarized in a table. The article describes the standards for CGI, with the definition of the grades based on the minimum tensile strength. It also provides information on the applications of compacted graphite iron castings.

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 discusses the advantages of polymer matrix composite for automotive application in terms of design drivers, noise, vibration, harshness efficiency, process materials property constraints, safety and reliability, design optimization, structural and appearance requirements, recyclability, and processability. It describes the properties of high-volume composites used in automotive industries. The article provides a discussion on state-of-the-art and developing technologies in automotive field.

This article provides information on the compositions of alkaline and acid baths and process parameters for zinc-iron, zinc-cobalt, zinc-nickel, and tin-zinc plating.