Search Results for procurement contract

This article presents a discussion on the U.S army's position on corrosion control for wheeled tactical vehicles. It addresses the army requirement for corrosion control. The U.S. Army Tank-automotive and Armaments Command (TACOM) defines the corrosion prevention and control requirements in the procurement document. The article summarizes requirements from a procurement document. As required by the procurement contract, corrosion-control technologies used in a vehicle system need to be evaluated to determine their benefit. The article provides information on testing systems, which help to meet the army's needs. It includes information on supplemental corrosion protection, which improves the corrosion resistance of a material.

This article first describes a typical additive manufacturing (AM) process chain, which involves the transaction of digital information to manufacture physical products. The digitized nature of AM exposes the technology to increased vulnerabilities, posing a hurdle to its mass adoption. The article presents motivation for using blockchain, which is a decentralized, immutable ledger that is shared on a peer-to-peer network. The article presents the advantages of blockchain integration to AM supply chains. These involve aspects of data security, supply chain and logistics, finance, value creation, and scope expansion. The article also presents the opportunities and challenges of blockchain technology.

This article provides a perspective on United States (U.S.) Department of Defense (DOD) specifications, standards, handbooks, and related documents, as well as their role in the corrosion prevention and control activities in the U.S. military.

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.

This article describes the four basic steps of the purchasing process of cast components. These steps include defining requirements and developing a purchasing plan; requesting and evaluating bids from potential sources; selecting a source and negotiating contract terms; and carrying out the contract and pursuing continuous improvement. It provides guidance on purchasing cast components and explains specific issues and approaches that have proven to be useful in purchasing castings. The article presents a list of the most significant considerations when attempting to determine the overall cost and design requirements of a metal casting.

A test plan specifies material properties to be evaluated, selects test methods, eliminates options offered by standard test methods by selecting specific specimen and test configurations, and defines success criteria. This article discusses various testing objectives that affect the execution of testing programs. The testing objectives include development of test matrices, testing standards, specimen preparation, environmental conditioning, instrumentation and data acquisition, failure modes, and data interpretation and recording.

This article presents an overview of common heat treating problems arising due to poor part design, material incapabilities, difficult engineering requirements, incorrect heat treatment practice, and nonuniform quenching with emphasis on distortion and cracking of quenched and tempered steels. It provides useful information on selection of steels for heat treatment, and discusses the causes of residual stresses, distortion (size and shape), and size changes due to hardening and tempering. The article elucidates the control techniques for such distortions. It describes the importance of decarburizing, and discusses the problems caused by heating, cracking, quenching, typical steel grades, and design.

This article provides general guidelines for casting design to provide progressive solidification, minimize heat concentration, eliminate cores, and prevent distortion. Casting design also affects tolerances. Casting tolerances depend on the alloy being poured, the size of the casting, and the molding method used. Designers can predict the effect of the design on the structure of the final part using solidification simulation models, namely finite element and finite difference models, and rapid prototyping. The article concludes with a short note on how the quality is assured in the foundry.

The inclusion of damage tolerance design and a systematic review of design procedures allow the U.S. Air Force to design, manufacture, and maintain systems that are structurally safe and economically prudent. After a brief introduction of fracture mechanics, this article describes the particular aspects that relate to damage tolerance in aircraft design. It discusses the use of fracture mechanics as a method of predicting failure, understanding failure mechanisms, and suggesting inspection methods to protect against failure in pressure vessels. Various programs of U.S. Air Force to design aircraft structure, namely, airframe structural integrity programs, engine structural integrity program, and mechanical subsystems structural integrity program are also discussed.

Additive manufacturing (AM) has gained increased significance and has been adopted across many industries for various applications. Specific net-shape AM fabrication methods, such as laser powder-bed fusion (LPBF), have matured significantly, leading to aerospace sector R&D focused on the feasibility of using flagship alloys to manufacture complex components. This article presents one example of an aluminum alloy design tailored for laser powder-bed fusion AM. It discusses the integrated computational materials engineering design approach. The article also presents the design for high-strength, high-temperature aluminum alloys.

This article discusses the concepts of quality control (QC) and quality assurance (QA), and clarifies the differences and similarities in the roles and responsibilities of QC and QA personnel. It describes the inspection procedures used to verify proper surface preparation and installation of the protective coating/lining system. Prior to beginning surface-preparation operations, many specifications will require a presurface-preparation inspection to verify the correction of fabrication defects and removal of surface contamination such as grease, oil, cutting compounds, lubricants, and chemical contaminants. When inspecting concrete prior to coating installation, three areas of concern exist: surface roughness, moisture content in concrete, and acidity/alkalinity of the surface. The article provides information on the industry standards for assessing surface cleanliness. It details postcoating application quality requirements, including measuring of dry-film thickness, assessing intercoat cleanliness, verifying minimum and maximum recoat intervals, performing holiday/pinhole detection, conducting cure/hardness testing, and assessing adhesion of the applied coating system.

High-temperature-resistant polymers are used in aerospace, electronic, and other applications that demand outstanding elevated-temperature physical and mechanical properties. This article discusses the general characteristics of condensation-type polyimides and polymerization of monomer reactants (PMR) polyimides. It provides information on the applications of PMR-15 with illustrations.

Independent verification of coating system performance can be based on laboratory testing and/or field exposure. Qualification testing is a critical component to coating system selection. This article focuses on performance evaluations that are used to prequalify coating systems, namely, facility-specific, industry-specific, coating-type-specific, or a combination of these. It describes the standard laboratory tests used to generate performance data, namely, physical, compositional, chemical exposure, and application characteristics tests. The pros and cons of using manufacturer-generated data versus independently generated data are discussed. The article provides information on accelerated corrosion/weathering testing and nuclear level 1/level 2 service coatings qualification. It also describes the procedures for establishing minimum performance requirements and for determining when requalification testing may be required.

This article reviews business cases for additive manufacturing (AM) and offers suggestions on monetizing the flexibility created by AM through a deep understanding of the most applicable cost drivers. It also reviews the common adoption drivers for AM and provides suggestions on how to take advantage of them. The AM maturity model breaks down potential additively manufactured products into five levels: preproduction, production influence, substitution, functional designs, and multifunctional. The business value of these levels is further described and evaluated with respect to the triple constraint of project management. The article then focuses on success factors for implementing AM.

This article reviews corrosion problems in the U.S. Department of Defense (DoD) and discusses management and maintenance aspects of the practices that address the cost and readiness. It describes the plans to institute corrosion prevention and control strategies under DoD directives in engineering design, material selection, and fabrication processes for new acquisitions. The article also suggests a long-term strategy to reduce the cost of corrosion control.

Casting offers the cost advantages over other manufacturing methods for most components. This article reviews the aspects of castings with which designers should be familiar, as well as the methods used by foundries to produce high-integrity castings. It discusses the design concepts that designers and foundries can use to obtain maximum performance from cast parts. The article describes the effects of casting discontinuities on properties, including porosity, inclusions, hot tears, metal penetration, and surface defects. A discussion on hot isostatic pressing treatment of castings is also provided. The article concludes with information on solidification simulation and its use in designing castings.

This article focuses on binder-jetting technologies in additive manufacturing (AM) that produce metal artifacts either directly or indirectly. The intent is to focus on the most strategic and widespread uses of the binder jetting technology and review some of the challenges and opportunities for that technology. The discussion includes a historical overview and covers the major steps involved and the advantages of using the binder jetting process. The major steps of the process covered include printing, curing, de-powdering, and sintering.

This article reviews the steps involved in presurface-preparation inspection: substrate replacement; removal of weld spatter, rounding of sharp edges, and grinding of slivers/laminations; and removal of rust scale, grease, oil, and chemical (soluble salt) contamination. It focuses on surface preparation methods that range from simple solvent cleaning to hand and power tool cleaning, dry and wet abrasive blast cleaning, centrifugal wheel blast cleaning, chemical stripping, and waterjetting for the application of the coating system. In addition, the article provides a description of the Society for Protective Coatings' (SSPC) standards and NACE International standards as well as the International Organization for Standardization (ISO) standards and International Concrete Repair Institute (ICRI) guidelines for surface cleanliness.

This article describes the technology of thermal spraying with regard to tribological applications. It introduces the basics of tribology and presents the fundamentals of thermal spraying and the relevant process variants and suitable materials. Specific application areas are described regarding the different forms of elementary movement in the corresponding tribological system. The article provides an overview of thermal spray coatings and possible uses for friction and wear control, besides operating as corrosion protection and a thermal barrier. The article provides examples that illustrate how tribological performance can be improved.

This article provides a basic overview of bridge corrosion, where it occurs on steel and concrete bridge structures, and how to prevent corrosion by using coatings. It describes types of bridge designs, with illustrations, and presents information on how corrosion occurs in different bridge zones and areas, with illustrations. The article concludes with a discussion on the common methods of coating systems applications on bridge structures and key elements in coating condition assessment.