Resistance soldering (RS) can be applied to electrically conductive materials that allow the passage of electric current. The process can be used for selective spot soldering of small components, for the soldering of closely placed parts on an assembly, or for heat restriction when necessary. This article explains that the RS process can be used in all soldering operations and with all solderable metals. It provides information on the applications, preassembly practices, the equipment used and the training required for soldering personnel.

This article discusses the safety issues associated with the design and operation of thermal spray booths and spray box structures and the equipment or systems required for operating thermal spray processes. It describes the design elements necessary to mitigate sound, dust and fume, ultraviolet light, and mechanical hazards. The means selected for safeguarding personnel must be based on a formal risk assessment that meets ANSI/RIA standards. The safeguards include sensing devices, barriers, awareness signals, procedures, and training. It also provides guidelines that are intended to increase the safety awareness and the use of safety practices for gas and liquid piping and electrical equipment within thermal spray installations.

Visual inspection (VI) is the oldest inspection technique man has used as a quality-control tool to evaluate products, assess their final form in terms of fabrication accuracy and external features based on experience, and decide on their acceptance or rejection. This article discusses the basic principles of visual inspection in terms of direct visual examination and indirect visual examination as well as advantages and limitations of visual inspection. It reviews the factors affecting the effectiveness of VI as a nondestructive testing (NDT): lighting conditions of observation, condition of surface under inspection, physical state/condition of inspector, proper training of personnel and level of expertise, and knowledge of applicable standards. The article provides schematic illustrations of rigid borescopes, fiberscopes, and videoscopes. It concludes with a discussion on automated optical inspection systems.

Health and safety are critically important issues, and there are numerous aspects of the production and use of metal powders that may entail exposure to hazardous conditions. This article provides a discussion on the issues associated with the safe production and handling of metal powders and the safe operation of continuous mesh belt sintering furnaces with combustible atmospheres. It also provides a comprehensive high-level overview of the safety-related issues and concerns related to the use of compacting presses in the manufacturing sector.

Maintainability is a function of the durability, damage tolerance, and repairability of a structure. This article discusses the configurations of composite structures, such as sandwich, stiffened-skin, and monolithic structures, used in commercial aircraft composites. It describes the considerations for maintainability of the composite structures during the conceptual design phase. Sources of the defects and damage, such as manufacturing defects and in-service defects, are reviewed. The article describes the nondestructive inspection methods that are used in the repair of composite structures to locate damage, characterize the extent of damage, and ensure post-repair quality. It lists suggestions that can be used as design guidelines for adhesive bonding, general composite structure, sandwich structure, material selection, and lightning-strike protection. The article also provides the basic considerations for personnel, facilities, and equipment during maintenance.

Risk assessments (RAs) must be customized to the specific workplaces and to the actual work being performed. It is performed to make the workers and their management aware of the hazards in the work environment, identify each risk in a methodical manner, and put in place a plan to mitigate the hazards. Information on risk assessment presented in this article provides a logical approach that can be taken to minimize risk and maximize thermal spray practitioners' safety. There are basically four steps to improving operational safety by using RAs: identifying the risks for each activity, rating the risk, putting in place the actions required to minimize risk, and reviewing and updating the RAs on a regular basis. The article presents two case studies to illustrate the concepts involved in RAs.

This article presents an overview of the rules, regulations, and techniques implemented to minimize the safety hazards associated with welding, cutting, and allied processes. Safety management, protection of the work area, process-specific safety considerations, and robotic and electrical safety are discussed. The article explains the use of personal protective equipment and provides information on protection against fumes, gases, and electromagnetic radiation. It concludes with a discussion on safe handling of compressed gases as well as the prevention and protection of fire and explosion.

The purpose of accreditation is to evaluate and assure high-quality results from suppliers of products or services without incurring the costs associated with auditing each supplier. This article describes laboratory accreditation based on the general requirements of International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) Guide 25, "General Requirements for the Competence of Calibration and Testing Laboratories." The Guide 25 is a balanced standard that addresses quality system requirements of ISO 9000 and the technical requirements needed to perform testing or calibration. The article describes an accreditation process that would enhance the international acceptance of test data for mechanical testing laboratories.

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.

Dip soldering is accomplished by submerging parts to be joined into a molten solder bath. This article provides an overview of dip soldering, its applications, and the equipment used. The article also provides information on the safety measures to be taken by production personnel when operating solder pots.

In-process inspection during composite material lay-up is essential if the structural, dimensional, and environmental performance designed into a part is to be consistently achieved. This article discusses the requirements to be met by the facilities and equipment to produce high-quality composites. It reviews the procedures that are allowed and prohibited in controlled-contamination areas of lay-up. The article emphasizes significant areas, such as material control and lay-up process, in which quality-control personnel can be effective in preventing production problems. It concludes with a discussion on automated tape laying and fiber placement, as well as the numerically aided lay-up process.

Laser-beam welding (LBW) uses a moving high-density coherent optical energy source, called laser, as the source of heat. This article discusses the advantages and limitations of LBW and tabulates energy consumption and efficiency of LBW relative to other selected welding processes. It provides information on the applications of microwelding with pulsed solid-state lasers. The article describes the modes of laser welding such as conduction-mode welding and deep-penetration-mode welding, as well as major independent process variables for laser welding, such as laser-beam power, laser-beam diameter, absorptivity, and traverse speed. It concludes with information on various hazards associated with LBW, including electrical hazards, eye hazards, and chemical hazards.

This article provides a discussion on general nondestructive evaluation (NDE) science and considerations for specific technique selection. It explains the basic concept of flaw detection and evaluation and probability of detection. The article provides an overview of NDE methods with their applications, limitations, and advantages. It includes details on NDE codes, calibration standards, inspection frequency, guidance on how to perform inspections, applicability, and mandatory and nonmandatory practice. The article also provides tips on where to focus inspections in order to align with the likely areas of damage or degradation and a number of other aspects of inspection.

This article defines quality, quality assurance, quality control, and quality management of processes, products, and services. It describes the evolution of quality control and quality assurance in the coatings industry. The article also discusses the standards, quality programs, and certifications in the coatings industry.

Qualification of welding procedures and personnel is an important step to assure the quality and performance of any welded component or structure. This article summarizes common welding procedures, personnel qualification variables, and test methods. Welding procedure qualification tests can be categorized as either standard or special. The article discusses the purpose of qualifying a welding procedure to demonstrate that the resulting welds will meet prescribed quality standards and the qualification of the personnel.

During metal powder production, powder and/or dust handling, compaction, and part finishing operations, many safety and environmental risks exist. This article is a detailed account of the types of safety hazards that can exist and the issues that occur during metal powder handling, as well as recommendations and strategies that can be employed to both prevent and protect against damaging effects from powder exposure, fire and/or explosions, or environmental impact events.

High-frequency (HF) welding is a welding process in which the heat source used to melt the joining surfaces is obtained from HF alternating current (ac) resistance heating. This article discusses the advantages and disadvantages and applications of HF welding. It describes the equipment used for HF welding and the safety aspects to be considered during welding. The article concludes with a discussion on inspection and quality control.

This article provides information on personal protective equipment (PPE), consistent with the Occupational Safety and Health Administration's Personal Protective Equipment Standard (29 CFR 1910.132-138). This standard is intended to protect individuals from the risk of injury by creating a barrier against workplace hazards. This article provides guidelines for establishing PPE programs with an overview of the responsibilities for employers, supervisors, and employees, assessing hazards associated with thermal spray operations, and training workers about PPE, as well as guidelines for selecting, using, and maintaining PPE. It presents an overview of eye, face, head, hand, foot, hearing, fall, and respiratory protection. Respiratory and hearing protection should be used in conjunction with industrial hygiene monitoring.

Liquid penetrant inspection is a nondestructive method of revealing discontinuities that are open to the surfaces of solid and essentially nonporous materials. This article provides information on physical principles, evolution, description, and processing parameters of liquid penetrant inspection as well as materials used. It discusses some of the more generally used types of equipment used in penetrant inspection and their requirements. The article describes various penetrant methods and their selection criteria and provides information on precleaning and postcleaning of workpieces before and after penetrant inspection. The quality assurance and maintenance of penetrant inspection materials are also discussed. The article concludes with information on specifications and standards applicable to penetrant inspection.