Search Results for photochemical machining

Photochemical machining (PCM), also known as chemical blanking, is a metal-etching process that uses a photoresist to define the locations where the metal will be etched. This article describes the major steps used in the PCM process, namely, the preparation of the phototool, selection of the metal, preparation of the workpiece, masking with photoresists, etching, and stripping and inspection. The article reviews various design considerations for the PCM process. These include dimensional limitations, tolerances, and edge quality. The article also discusses the advantages, disadvantages, and applications of the PCM process.

This article discusses the properties of beryllium metals that require special attention when machining. It provides information on the considerations of S65 and selects 65 beryllium materials that are used for conducting tool wear studies and surface damage studies. The article highlights some of the precautions to be followed while machining beryllium metals. Information on the cutting oils, cutting tools, and speeds and feeds used in turning the beryllium are also provided. The article describes the chemical milling and photochemical machining methods that are used for etching beryllium components.

This article discusses the various categories of nontraditional machining processes that are subdivided according to the form of energy being harnessed. These include mechanical, electrical, thermal, and chemical methods.

Machining is a term that covers a large collection of manufacturing processes designed to remove unwanted material, usually in the form of chips, from a workpiece. This article discusses the basic classes of machining operations, including conventional, abrasive, and nontraditional, and outlines the type of costs incurred by the process. It describes the types of machining equipment, including general-purpose machine tools, production machining systems, and computer numerically controlled machining systems. The article lists the common classes of metallic work materials, in order of decreasing machinability. It also shows the range of dimensional and surface finish tolerances in graphical form that can be achieved using various machining processes under general machining conditions.

Nickel-base alloys can be machined by techniques that are used for iron-base alloys. This article discusses the effects of distortion and microstructure on the machinability of nickel alloys. It tabulates the classification of nickel alloys based on machining characteristics. The article describes the machining operations performed on nickel alloys, such as turning, planing and shaping, broaching, reaming, drilling, tapping and threading, milling, sawing, and grinding. It provides information on the cutting fluids used in the machining of nickel alloys. The article also analyzes nontraditional machining methods that are suitable for shaping high-temperature, high-strength nickel alloys. These include electrochemical machining, electron beam machining, and laser beam machining.

This article focuses on a variety of laser beam machining (LBM) operations of aluminum and its alloys, namely, laser cutting, laser drilling, laser milling, laser turning, laser grooving, laser scribing, laser marking, and laser micromachining. It presents different approaches for carrying out machining operations, laser processing parameters, efficiency and accuracy of the process, and the effect of laser processing parameters on the quality of the machined surface. The article provides an overview of the various conventional (chip forming) and nonconventional machining techniques employed for aluminum-based materials. A comparison of the various aspects of LBM with other non-conventional techniques is also presented. The article also describes the features of LBM techniques employed for aluminum and its alloys for different types of machining.

Coining is a closed-die forging operation in which all surfaces of the workpiece are confined or restrained, resulting in a well-defined imprint of the die on the workpiece. This article focuses on the coining equipment (hammers and presses), lubricants, and general and special die materials used in the coining process. It discusses the coinability of metals such as steels, copper, and composite metals. The article describes the control of dimensions, surface finishes, and weight of coined items. It concludes with a discussion on processing problems and solutions.

This article discusses the principal process steps, specifications, defects, applications, advantages, and disadvantages of chemical milling (CM) in aerospace industries. The process steps include precleaning, masking, scribing, etching, final cleaning, stripping, and mechanical finishing. The article describes the variables that affect undercut and surface finish obtained by CM. The mechanical properties of chemically milled parts are also discussed.

Laser beam machining removes, melts, or thermally modifies a material by focusing a coherent beam of monochromatic light on the workpiece. This article describes the principal lasers used in metal processing: neodymium-glass, carbon dioxide, and neodymium-doped yttrium aluminum garnet lasers. It discusses the operating parameters of concern in percussion drilling and trepanning. The process variables in surface treatment and laser cutting, as well as the operating parameters of concern in laser welding are reviewed. The article also explains the various categories of surface treatment: heat treating, cladding, surfacing, glazing, and marking.

Safety is an important consideration in all welding, cutting, and related work. This article discusses the basic elements of safety general to all welding, cutting, and related processes. It includes safety procedures common to a variety of applications. The most important component of an effective safety and health program is management support and direction. The article reviews the role of management, training, housekeeping, and public demonstrations in welding safety to minimize personal injury and property damage. It provides information on the safety measures for eye and face protection in various welding and cutting operations. Injuries and fatalities from electric shock in welding and cutting operations can occur if proper precautionary measures are not followed. The article discusses the electrical safety aspects to be considered for various welding and cutting operations.

This article describes post-processing techniques for machining, finishing, heat treating, and deburring used to remove additive manufacturing (AM) metallic workpieces from a base plate and subsequent techniques to enhance printed workpieces. The AM processes include powder bed fusion, binder jetting, and direct energy deposition. The discussion provides information on powder removal, powder recycling and conditioning, part removal, and part enhancement. The mechanism, applications, advantages, and limitations of mechanical, radiation, and chemical-finishing processes as well as the properties of the resulting material are also covered.

Additive manufacturing (AM) is a revolutionary technology that fabricates parts layerwise and provides many advantages. This article discusses polymer AM processes such as material extrusion, vat photopolymerization (VPP), powder-bed fusion (PBF), binder jetting (BJ), material jetting (MJ), and sheet lamination (SL). It presents the benefits of online monitoring and process control for polymer AM. It also introduces the respective monitoring devices used, including the models and algorithms designed for polymer AM online monitoring and control.

This article reviews the applications of traditional glasses in architecture, transportation, construction, houseware, containers, and fibers. It also describes uses of specialty glasses for aerospace and military applications, biomedical and dental applications, chemical-resistant applications, lighting, information display, electronic processing and electronic devices, optical and ophthalmic products, and communications equipment.

Drawing is a process by which a workpiece is pulled against a die to produce a wire, bar, or tube with smaller cross sectional area compared with the initial stock. This article discusses the variables that affect the drawing process and the parameters that influence friction, lubrication, and wear. These parameters include process, lubricant, workpiece, and tooling. The article provides information on dry and wet lubrication in wire drawing. The dry lubrication refers to use of solid lubricants while wet lubrication refers to the practice of providing a liquid lubricant to the workpiece-die interface. The article describes the most common types and causes of die wear: abrasive wear, adhesive wear, surface fatigue wear, thermal fatigue wear, and catastrophic failure. It concludes with a discussion on the surface treatment and texturing that are used to reduce die wear in drawing operations.