Laser has found its applications in cutting, drilling, and shock-peening operations of manufacturing industry because of its accurate, safe, and rapid cutting property. This article provides an account on the fundamental principles of laser cutting (thermal), drilling, and shock-peening processes of which emphasis is placed on thermal laser cutting. It details the principal set-up parameters, such as the laser beam output, nozzle design, focusing optic position and characteristics, assist gases, surface conditions, and cutting speed. A discussion on the types of gas, supply system, purity level, and flow rates of lasing and assist gases is also provided. The article also describes the metallurgies and other key material considerations that impact laser-cutting performances and includes examples of laser cutting of nonmetal materials.

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.

This article describes the influence of steel chemical compositions and microstructure on machining processes. It discusses the various microstructural phases of standard carbon and alloy steels, which influence machinability. The article reviews the expected response of several traditional machining operations, such as turning, drilling, milling, shaping, thread cutting, and grinding, to the microstructure of standard steel grades. It also explains the technologies in non-traditional machining processes, such as abrasive waterjet cutting, electrical chemical grinding, and laser drilling.

This article describes the use of conventional machining techniques, laser cutting and water-jet cutting for producing finished composite parts. It explains two representative polymer-matrix composites--graphite and aramid composites--and discusses the machining and drilling problems such as delamination and fiber or resin pullout. The article describes machining and drilling techniques and the necessary tools and cutting parameters. It presents a description of laser cutting. The article also provides information on the advantages, disadvantages, cutting characteristics, and applications of water-jet cutting and abrasive water-jet cutting.

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.

This article presents general guidelines for machining metal matrix composites (MMC) and honeycomb structures. It provides guidelines for machining of specific MMCs, namely, aluminum-boron, aluminum-SiC, aluminum-Al 2 O 3 , and titanium-SiC MMCs. In addition, the article discusses the various parameters influencing drilling of dissimilar-material laminates.

This article focuses on the machining of reactive metals which refer collectively to the elements titanium, hafnium, and zirconium. It provides guidelines for machining titanium and titanium alloys and describes machining operations, such as turning, milling, drilling, tapping, reaming, grinding, and sawing, performed on titanium and its alloys. The article also provides information on electrochemical machining (ECM), chemical milling (CHM), and laser beam machining (LBM) for titanium and titanium alloys. Guidelines for machining zirconium alloys and hafnium are also provided. The article provides a short description of turning, milling, and drilling operations performed on zirconium alloys and hafnium. It also discusses health and safety considerations related to zirconium and hafnium.

Electron beam machining (EBM) uses a focused beam of high-velocity electrons to remove material. This article provides a description of equipment used for EBM and discusses the process characteristics, applications, advantages, and disadvantages of electron beam drilling.

This article provides a history of electron and laser beam welding, discusses the properties of electrons and photons used for welding, and contrasts electron and laser beam welding. It presents a comparison of the electron and laser beam welding processes. The article also illustrates constant power density boundaries, showing the relationship between the focused beam diameter and the absorbed beam power for approximate regions of keyhole-mode welding, conduction-mode welding, cutting, and drilling.

This article focuses on noble and neutral coatings and the requirements necessary to achieve successful industrial applications. These include corrosion and wear control and repair applications in processing and chemical industries, and valve and downhole drilling applications in the petrochemical industry. The article also discusses substrate chemistry and preparation; coating selection process and microstructure; sealing by chemical, post-heat treatments, and laser processing; and thermal spray process alternatives.

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 presents a summary of the current and new materials and processing techniques for thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). Different thermal spraying and postspraying processing techniques are required to produce coatings with optimal performance. For TBCs and EBCs, the elastic modulus, mechanical strength, and toughness values are extremely important in predicting failure behavior under stress and strain conditions, mainly for modeling purposes. Sand and/or volcanic ash particles are molten in the hot zones of turbines and deposited over TBCs and EBCs. They form calcium-magnesium-aluminosilicate (CMAS) glassy deposits.