Search Results for wire embedding

This article provides an overview of the implementation of wire embedding with ultrasonic energy and thermal embedding for polymer additive manufacturing, discussing the applications and advantages of the technique. The mechanical and electrical performance of the embedded wires is compared with that of other conductive ink processes in terms of electrical conductivity and mechanical strength.

Superconductors are materials that exhibit a complete disappearance of electrical resistivity on lowering the temperature below the critical temperature. A superconducting material must exhibit perfect diamagnetism, that is, the complete exclusion of an applied magnetic field from the bulk of the superconductor. Superconducting materials that have received the most attention are niobium-titanium superconductors (the most widely used superconductor), A15 compounds (in which class the important ordered intermetallic Nb3Sn lies), ternary molybdenum chalcogenides (Chevrel phases), and high-temperature ceramic superconductors. This article provides an overview of basic principles of superconductors and the different classes of superconducting materials and their general characteristics.

The majority of currently used additive manufacturing (AM) processes are solidification based (SAM). Another class of AM processes consists of those that rely on deformation (DAM) to place material instead of solidification. Although SAM processes are much more widely used, as research and development continues in DAM processes, they are becoming increasingly attractive, especially for the AM of metals. This article discusses some of the more widely used DAM processes, namely ultrasonic additive manufacturing, cold spray process, and friction stir welding, focusing on their applications, advantages, and limitations.

This article discusses the generic situation of steel reacting with the environments found in structures. Two environments are specifically discussed: atmospheric and cementitious. The article describes the utility of different corrosion protection methods for atmospheric corrosion and cementitious systems. It presents examples of problems that have arisen in the corrosion performance of steel.

Bridges and highways are core components of transportation system and range from pavements with earth, gravel, or stone covered by a thin bituminous surface course to a continually reinforced Portland cement concrete (PCC) roadway with or without a bituminous wear course. This article provides information on bridges and dowels and the reinforcement used in PCC roadways that suffer from corrosion. An overview is provided on the rise in awareness of the corrosion issues affecting bridges and highways. The chemistry and structure of concrete and its role as an electrolyte in promoting corrosion are also discussed. The article addresses reinforcement, including conventional, prestressed, cable stays, and corrosion-resistant reinforcement. It deals with the electrochemical methods for the inspection and corrosion control of embedded reinforcement. The article also reviews the corrosion of metal bridges and corrosion control, including the use of weathering steels and coating systems.

The ultrasonic additive manufacturing (UAM) process consists of building up solid metal objects by ultrasonically welding successive layers of metal tape into a three-dimensional shape with periodic machining operations to create detailed features of the resultant object. This article provides information on the materials, welding parameters, process consumables, procedures, and applications of the UAM. It describes the methods for determining metallurgical and mechanical properties of solid metal parts to assess the range of materials and applications for which the process is suited. These methods include peel testing, push-pin testing, and microhardness/nanohardness testing. The article also reviews the issues to be addressed in maintaining UAM fabrication quality.

Mechanical finishes usually can be applied to aluminum using the same equipment used for other metals. This article describes the two types of grinding used in mechanical finishing: abrasive belt grinding and abrasive wheel grinding. It reviews the binders and fluid carriers used in buffing, and discusses satin finishing and barrel finishing. It also describes lapping and honing techniques that are of special interest in treating aluminum parts that have received hard anodic coatings. Honing recommendations for aluminum alloys are presented in a table.

This article presents the fundamentals of stray-current corrosion caused by electric rail transit systems. It describes the various corrosion-control design elements for the electric rail system. These design elements include substation spacing and grounding, track and track slab design, and construction acceptance criteria. The impacts of the electric rail construction in underground utilities are discussed. Direct physical interferences, maintenance access encroachments, stray-current effects, and utility relocation design considerations, are discussed. The article also reviews construction issues such as funding, sequencing, and working clearances. It concludes with information on the post-construction monitoring and maintenance for stray-current corrosion control.

This article presents an overview of the electric and magnetic parameters and discusses the significance of these parameters for electronic applications. It describes the components of analog and digital electronic circuits. The article reviews the augmenting technologies: magnetic and special technologies such as electrooptical.

Ternary molybdenum chalcogenides stands for a vast class of materials, whose general formula is MxMO6X8, where, M is a cation and X is a chalcogen (sulfur, selenium, or tellurium). Possible applications of some of these are as high field superconductors (that is, >20 T, or 200 kG). This article discusses the fabrication methods of PbMo6S8 (PMS) and SnMo6S8 (SMS), including hot processing and cold processing. It provides a short note on the superconducting properties of PMS wire filaments and their applications in processes requiring high magnetic fields, such as high-energy physics, thermonuclear fusion, and nuclear magnetic resonance.

This article describes the operation procedures of wire rolling in a Turks Head machine. It discusses spring coiling, as well as the manual and power bending used in the wire forming process. The article contains a table that lists examples of several wire-forming production problems and solutions. Lubricants for wire forming such as inorganic fillers, soluble oils, and boundary lubricants are reviewed. The article also analyzes the applications of lubricants in wire forming.

Although stainless steel is naturally passivated by exposure to air and other oxidizers, additional surface treatments are needed to prevent corrosion. Passivation, pickling, electropolishing, and mechanical cleaning are important surface treatments for the successful performance of stainless steel. This article describes the surface treatment of stainless steels including abrasive blast cleaning, acid pickling, salt bath descaling, passivation treatments, electropolishing, and the necessary coating processes involved. It also describes the surface treatment of heat-resistant alloys including metallic contaminant removal, tarnish removal, oxide and scale removal, finishing, and coating processes.

This article discusses the procedures used for pickling nickel and nickel alloys. Nickel alloys can be divided into four groups: high-nickel alloys, nickel-copper alloys, nickel-chromium alloys, and nickel-iron-chromium alloys. Alloys within each composition group that has similar surface conditions are pickled in the same solutions using the same procedures. The article discusses three different surface conditions for pickling these nickel alloys: bright annealed white surface requiring removal of tarnish by flash pickling; bright annealed oxidized surface requiring removal of a layer of reduced oxide, sometimes followed by a flash pickle to brighten; and black or dark-colored surface requiring removal of adherent oxide film or scale. The article also reviews specialized pickling operations of nickel alloys and various cleaning and finishing operations, including grinding, polishing, buffing, brushing, and blasting.

Aging is a process where the structural and/or functional integrity of components will be continuously degraded by exposure to the environmental conditions under which they are operated. This article discusses aging mechanisms in various components of military systems such as structural parts, engines, and subsystems. It describes the aging management processes such as full-scale structural testing and practical life-enhancement methods. The article reviews control and prevention systems such as usage and health monitoring systems necessary to provide effective corrosion maintenance on military systems. Failure prediction techniques, namely, the equivalent pre-crack size approach, life-cycle cost modeling and simulation, and holistic life-prediction methodology are also discussed.

Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique that leverages the principles of ultrasonic welding, mechanized tape layering, and computer numerical control (CNC) machining operations to create three-dimensional metal parts. This article begins with a discussion on the process fundamentals and process parameters of UAM. It then describes metallurgical aspects in UAM. The article provides a detailed description of a wide range of mechanical characterization techniques of UAM, namely tensile testing, peel testing, and pushpin testing. The article ends with information on sensor embedding.