Search Results for electron beam treatment

This article reviews cleaning and finishing operations that have proven to be effective on titanium, its alloys, and semi-fabricated titanium products. It explains how to remove scale, tarnish films, grease, and other soils and how to achieve required finishes and/or improve wear and oxidation resistance through the use of polishing, buffing, and wire brushing operations. The article also covers a wide range of surface modification and coating processes, including ion implantation, diffusion, chemical and physical vapor deposition, plating, anodizing, and chemical conversion coatings as well as sprayed and sol-gel coatings and laser and electron-beam treatments.

Electron beam hardening (EBH), with some special characteristics in comparison to other heat treatment technologies, allows beam deflection frequencies of up to 100 kHz. This article illustrates the principles of different thermal electron beam technologies, including beam-deflection, continuous EB interaction, EB flash, as well as multifield EB-deflection and multiprocess techniques. It characterizes the technical and technological possibilities for EBH in comparison to other surface-layer hardening processes. The article also discusses the technical design of electron beam facilities and the applications of EBH.

This article focuses on the use of electron beam (EB) for near-net shape processing based on the wire feed material-delivery method. EB deposition processes start with a 3-D model designed in a computer-aided design (CAD) environment, where the deposition path and process parameters are generated. The article provides a description of the electron beam direct manufacturing (EBDM) system used for manufacturing of target parts with the aid of a case study. The control of the essential variables of dynamic beam deflection is also reviewed. The article also includes information on the applications of high-frequency multibeam processes, namely, selective surface treatment, multiple-pool welding, and pre- and post-heat treating.

Aluminum and its alloys are characterized by their low hardness and less satisfactory tribological performance. These limits can be overcome by means of load-specific surface engineering. This article provides information on the structure and properties of nitrided layers, and the technologies and mechanisms used for nitriding aluminum and its alloys. It also describes the nitriding behavior of aluminum alloys. The article concludes by describing how a combination of technologies can be utilized to achieve aluminum nitride with the highest tribological properties.

Weldability refers to the ease of welding a material under the imposed fabrication conditions to perform satisfactorily during service. This article is a comprehensive collection of tables that summarize the general weldability of cast irons, steels, nonferrous metals, and their alloys by common fusion welding processes.

This article describes general welding characteristics such as weld microstructure and weldability. The correlations of preheating and postweld heat treatment practices with carbon contents and welding characteristics of martensitic stainless steels are reviewed. The article contains a table that lists the electrodes and welding rods suitable for use as filler metals in the welding of martensitic stainless steels. It provides specific arc welding procedural recommendations for the commonly welded martensitic stainless steels. Martensitic stainless steel joining methods such as laser-and electron-beam welding, resistance welding, flash welding, and friction welding, are discussed.

This article discusses the fundamentals and applications of localized heat treating methods: induction hardening and tempering, laser surface transformation hardening, and electron-beam heat treatment. The article provides information about equipment and describes the selection of frequency, power, duration of heating, and coil design for induction hardening. The article also discusses the scope, application, methods, and operation of flame hardening.

This article describes the joint preparation, fit-up and design of various types of laser beam weld joints: butt joint, lap joint, flange joint, kissing weld, and wire joint. It explains the use of consumables for laser welding and highlights the special laser welding practices of steel, aluminum, and titanium engineering alloys. Laser weld quality and quality assessment are described with summaries of imperfections and how its operations contribute to providing repeatable and reliable laser welds. Relevant laser weld quality specifications are listed.

This article provides detailed information on the instrumentation and principles of the scanning electron microscope (SEM). It begins with a description of the primary components of a conventional SEM instrument. This is followed by a discussion on the advantages and disadvantages of the SEM compared with other common microscopy and microanalysis techniques. The following sections cover the critical issues regarding sample preparation, the physical principles regarding electron beam-sample interaction, and the mechanisms for many types of image contrast. The article also presents the details of SEM-based techniques and specialized SEM instruments. It ends with example applications of various SEM modes.

Surface hardening improves the wear resistance of steel parts. This article focuses exclusively on the methods that involve surface and subsurface modification without any intentional buildup or increase in part dimensions. These include diffusion methods, such as carburizing, nitriding, carbonitriding, and austenitic and ferritic nitrocarburizing, as well as selective-hardening methods, such as laser transformation hardening, electron beam hardening, ion implantation, selective carburizing, and surface hardening with arc lamps. The article also discusses the factors affecting the choice of these surface-hardening methods.