Search Results for design on quality

This article describes how design can unfavorably affect product quality. It provides information on the total quality management philosophy, emphasizing the principles of quality management. The article discusses various methods for evaluating a product design for quality. It presents design guidelines that are intended to provide products with a potential for higher levels of quality.

This article describes the joint preparation, fit-up and design of various types of laser beam weld joints: butt joint, lap joint, flange joint, kissing weld, and wire joint. It explains the use of consumables for laser welding and highlights the special laser welding practices of steel, aluminum, and titanium engineering alloys. Laser weld quality and quality assessment are described with summaries of imperfections and how its operations contribute to providing repeatable and reliable laser welds. Relevant laser weld quality specifications are listed.

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.

This article addresses problems, such as “in spec” dilemma and on-target key, associated with traditional approaches to quality. It discusses major robust design techniques, tools, and concepts, such as quality loss function, parameter design, tolerance design, signal-to-noise ratio, technology development, and orthogonal arrays.

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.

This article discusses Allenby's two streams for environmental aspects of design: generic and specific concerns. Generic concerns include guidelines that provide the structure in which specific techniques can be developed and used. Specific methods are environmentally responsible for design and specific information that engineers can use. These methods include life cycle assessment, environmental impact assessment, quality function deployment, design for “X”, failure modes and effects analysis, and design for disassembly.

The process of optimization involves choosing the best solution from a pool of potential candidate solutions. This article provides a description of some classes of problems and the optimization methods that solve them. These problems include the deterministic single-objective problem, the deterministic multiobjective problem, and the nondeterministic, stochastic optimization problem. The article presents several complementary approaches to solve a wide variety of single-objective and multiobjective mechanical engineering applications. Multiobjective optimization study and stochastic optimization studies are also discussed.

This article addresses classifications and designations for carbon and low-alloy steel sheet and strip product forms based on composition, quality descriptors, mechanical properties, and other factors. Carbon steel sheet and strip are available as hot-rolled and as cold-rolled products. Low-alloy steel sheet and strip are used primarily for applications that require the mechanical properties normally obtained by heat treatment. The descriptors of quality used for hot-rolled plain carbon steel sheet and strip and cold-rolled plain carbon steel sheet include structural quality, commercial quality, drawing quality, and drawing quality, special killed. The surface texture of low-carbon cold-rolled steel sheet and strip can be varied between rather wide limits. The modified low-carbon steel grades discussed in the article are designed to provide sheet and strip products having increased strength, formability, and/or corrosion resistance. The article also summarizes the key operations involved in the three alternative direct casting processes: thin slab, thin strip, and spray casting.

This article discusses the various roles and responsibilities of materials engineers in a product realization organization and suggests different ways in which materials engineers may benefit their organization. It also provides a summary of the concepts discussed in the articles under the Section “The Role of the Materials Engineer in Design” in ASM Handbook, Volume 20: Materials Selection and Design.

Tooling and assembly methodologies for advanced composites have steadily improved as a result of advancements in materials, through the use of computer-aided design/computer-aided manufacturing technology, and through application of sophisticated design for manufacturing and assembly concepts. This article reviews techniques and technologies that are used to control the quality of tooling and assembly methods for composite components.

This article focuses on the process design set-up procedure for brazing and soldering. It provides a detailed account of the types of base metals that can be joined by these processes, and reviews the factors to be considered to enhance the joint design. Criteria for selection of the right induction heating equipment to carry out the brazing or soldering operation are also provided. The article describes the types of brazing filler metals and joint designs. It also presents the types of inspection methods, namely, mechanical and visual, used to determine the quality of the brazed joint. Important considerations for the automation of induction-heated brazing applications are also discussed. The article concludes by emphasizing the need for documenting an in-control process which is a vitally important reference for questions or problems arising in the machine settings or part quality.

This article provides an overview of metal additive manufacturing (AM) processes and describes sources of failures in metal AM parts. It focuses on metal AM product failures and potential solutions related to design considerations, metallurgical characteristics, production considerations, and quality assurance. The emphasis is on the design and metallurgical aspects for the two main types of metal AM processes: powder-bed fusion (PBF) and directed-energy deposition (DED). The article also describes the processes involved in binder jet sintering, provides information on the design and fabrication sources of failure, addresses the key factors in production and quality control, and explains failure analysis of AM parts.

This article presents the importance of progressing from post-manufacturing inspection/verification to in-process inspection/verification methods. It lists the various quality assurance factors considered for typical composite laminate lay-up process. The article provides information on composite cure tooling that is fabricated from steel, aluminum, or high-temperature composite materials. The quality assurance for commercial applications is reviewed. The article concludes with a discussion on data fusion systems designed to provide nondestructive analysis data from fabrication and assembly processes for each individual composite part.

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.

The basic elements of control design are safety, process control, process verification, machine control, productivity, repeatability, and ease of setup. Effective systems of quality control/quality assurance are essential for heat treating practices. This article provides information on process control modes, as well as on process signatures of some items that require control, monitoring, verifying, and logging methods. It provides information on programmable logic controllers that have become efficient in machine control and monitoring. The article describes possible noise issues, National Electric Code clearance requirements, monitoring requirements, and machine accuracy that need to be considered when designing induction equipment.

When a heat of steel is melted and refined, it is necessary to solidify it into useful forms for further processing or final use. Ingot casting remains the preferred method for certain specialty, tool, forging, and remelted steels. This article discusses the methods, equipment, and theory for pouring, solidifying, and stripping steel ingots. It describes two basic types of pouring methods, top pouring and bottom pouring, and provides information on equipment such as hot tops, ingot molds, and stools. The design of the ingot is dictated by the application and type of steel involved. The article concludes with information on the applications of solidification simulation.