This appendix provides a brief review of thin film deposition methods and their uses in a question and answer format. The questions deal with recommended practices, process conditions, terminology, and classifications.

This chapter presents the theory and practice associated with the application of thin films. The first half of the chapter describes physical deposition processes in which functional coatings are deposited on component surfaces using mechanical, electromechanical, or thermodynamic techniques. Physical vapor deposition (PVD) techniques include sputtering, e-beam evaporation, arc-PVD, and ion plating and are best suited for elements and compounds with moderate melting points or when a high-purity film is required. The remainder of the chapter covers chemical vapor deposition (CVD) processes, including atomic layer deposition, plasma-enhanced and plasma-assisted CVD, and various forms of vapor-phase epitaxy, which are commonly used for compound films or when deposit purity is less critical. A brief application overview is also presented.

This chapter discusses some of the ways that the lessons learned from failures have benefitted society, leading to improved product designs, better materials, safer industrial processes, and more robust codes and standards. It also provides several examples of how the technology and procedures associated with aviation security have been upgraded in the wake of air disasters.

Ferritic stainless steels are essentially iron-chromium alloys with body-centered cubic crystal structures. Chromium content is usually in the range of 11 to 30%. The primary advantage of the ferritic stainless steels, and in particular the high-chromium, high-molybdenum grades, is their excellent stress-corrosion cracking resistance and good resistance to pitting and crevice corrosion in chloride environments. This chapter provides information on the classifications, properties, and general welding considerations of ferritic stainless steels. The emphasis is placed on intergranular corrosion, which is the most common cause of failure in ferritic stainless steel weldments. Two case histories involving intergranular corrosion failures of ferritic stainless steel weldments are included. A brief discussion on hydrogen embrittlement is also provided.

Stainless steel base metals and the welding filler metals used with them are chosen on the basis of suitable corrosion resistance for the intended application. This article describes several constitution diagrams that that have been developed to predict microstructures and properties. This is followed by discussions of weldability, cracking, and the engineering properties of stainless steel welds, namely martensitic stainless steels, ferritic stainless steel welds, austenitic stainless steels, and duplex stainless steels.

Powder metallurgy plays a central role in the production of nearly all beryllium components. This chapter describes the primary steps in the powder metal process and the work that has been done to improve each one. It explains how beryllium powders are made and how they are consolidated prior to sintering. It also compares and contrasts the properties of beryllium products made using different methods and provides composition and particle size data on commercially available powders.

This chapter describes the basic steps in the production of titanium ingots and their subsequent conversion to standards product forms. It explains how titanium ore is reduced to a spongy residue, then granularized, compacted, and melted (along with alloying additions) to form an ingot, which may be remelted several times to achieve the necessary properties. It also discusses the cause of defects and ingot imperfections and the benefits of billet reduction and grain-refinement processes.

This chapter focuses on high-pressure cold spray applications pertaining to repair and refurbishment in the aerospace, oil and gas, and power-generation industries, the last specifically involving repair of gas turbine components. Advantages of cold spray coating in the repair and refurbishment of structural engineering components are also discussed.

This chapter provides an overview of the state of the art in high-pressure cold spray equipment, including both spray systems and gas supply systems. The chapter describes the commercial cold spray systems developed by companies such as Cold Gas Technology (CGT) GmbH, Plasma Giken Company Ltd, Impact Innovations GmbH, and ASB Industries. Typical helium and nitrogen gas systems used in high-pressure cold spray processing are reviewed.

This chapter discusses coating technologies that are applicable to beryllium, including physical and chemical vapor deposition, thermal evaporation, electroplating, sputtering, ion plating, and plasma arc spraying. It describes the advantages and disadvantages of each method and the effect of temperature, pressure, and other process variables on the microstructures and properties developed.

This chapter covers the basic steps of the powder metallurgy process, including powder manufacture, powder blending, compacting, and sintering. It identifies important powder characteristics such as particle size, size distribution, particle shape, and purity. It compares and contrasts mechanical, chemical, electrochemical, and atomizing processes used in powder production, discusses powder treatments, and describes consolidation techniques along with secondary operations used to obtain special properties or improve dimensional precision. It also discusses common defects such as ejection cracks, density variations, and microlaminations.

Irradiation-assisted stress-corrosion cracking (IASCC) has been a topic of engineering interest since it was first reported in the 1960s, having been observed in stainless steel cladding on light water reactor fuel elements. This chapter summarizes the results of decades of investigation, showing that IASCC can essentially be defined as the intergranular cracking of austenitic alloys in high-temperature water, where both the material and its environment have been altered by radiation. Of the many interactions that can occur when metals and water are exposed to radiation, the international consensus is that the three with the greatest impact on crack growth rates are the formation of material defects, radiation-induced segregation, and chemical reactions that increase the corrosion potential of water. The chapter discusses each of these in great detail, and includes information on predictive modeling as well.

This chapter provides an overview of beryllium casting practices and the challenges involved. It discusses the stages of solidification, the effect of cooling rate, the difficulty of heat removal, and the potential for hot cracking. It describes common melting techniques, including vacuum induction melting, vacuum arc melting, and electron beam melting, and some of the ways they have been used to cast beryllium alloys. The chapter also includes information on metal purification and grain refinement procedures.

This chapter introduces the key powder fabrication attributes to assist in the identification of the right powders for an application. First, it describes the characteristics of engineering powders such as particle size distribution, powder shape and packing density, surface area, powder flow and rheology, and chemical analysis. The chapter then describes the general categories of powder fabrication methods, namely mechanical comminution, electrochemical precipitation, thermochemical reaction, and phase change and atomization. It provides information on the two largest contributors to powder price, namely raw material cost and conversion cost. The applicability of various processes to specific material systems is mentioned throughout this chapter.