Search Results for dent resistance

The automotive sheet alloy 6022 provides improved corrosion resistance, higher formability, and greater strength for dent resistance after thermal exposure compared with other automotive sheet alloys. This datasheet provides information on key alloy metallurgy, processing effects on mechanical properties, and fabrication characteristics of this 6xxx series alloy.

This datasheet provides information on composition limits, fabrication characteristics, processing effects on physical and tensile properties, and applications of sheet alloy 5182.

This article provides information on the classification of high-strength steels (HSS) and advanced high-strength steels (AHSS) and tabulates designation of HSS and AHSS as recommended by the American Iron and Steel Institute. It reviews the major grades of HSS and AHSS that are used or will potentially be used in industrial applications. The article discusses different stamping issues such as edge cracking and springback, encountered during forming of AHSS, and lists guidelines for reducing springback in stamped components. It concludes with a discussion on the major advantages and disadvantages of using HSS and AHSS in automotive applications.

This article describes dental alloy compositions and its properties. It discusses the safety and efficacy considerations of dental alloy devices. The article defines and compares interstitial fluid and oral fluid environments. Artificial solutions developed for the testing and evaluation of dental materials are summarized. The article examines the effects of restoration contact on electrochemical parameters and reviews the concentration cells developed by dental alloy-environment electrochemical reactions. The composition and characterization of biofilms, corrosion products, and other debris that deposit on dental material surfaces are discussed. The article evaluates the types of alloys available for dental applications, including direct filling alloys, crown and bridge alloys, partial denture alloys, porcelain fused to metal alloys, wrought wire alloys, soldering alloys, and implant alloys. The effects of composition and microstructure on the corrosion of each alloy group are also discussed. The article concludes with information on the tarnishing and corrosion behavior of these alloys.

This article presents the damage tolerance criteria for military composite aircraft structures to safely operate the structures with initial defects or in-service damage. It describes the effects of defects, such as wrinkles in aircraft structures, and the reduction in compressive strength and tensile strength. The article reviews low velocity impacts in aircraft structures in terms of resin toughness, laminate thickness, specimen size and impactor mass, and post-impact fatigue. It explains the tension strength analysis, such as linear elastic fracture mechanics and R-curve methods, to predict the residual strength of the structures.

Contact fatigue is a surface-pitting-type failure commonly found in ball or roller bearings. This article discusses the mechanisms of contact fatigue found in gears, cams, valves, rails, and gear couplings. It discusses the statistical analysis of rolling contact bearing-life tests. The article concludes with information on various approaches that improve the contact fatigue resistance of rolling contact systems.

This article discusses the failure analysis of several steel transmission pipeline failures, describes the causes and characteristics of specific pipeline failure modes, and introduces pipeline failure prevention and integrity management practices and methodologies. In addition, it covers the use of transmission pipeline in North America, discusses the procedures in pipeline failure analysis investigation, and provides a brief background on the most commonly observed pipeline flaws and degradation mechanisms. A case study related to hydrogen cracking and a hard spot is also presented.

One of the most frequently cited advantages of ceramics in dentistry relates to aesthetics, and the same applies for dental implants. Zirconia has emerged as the material of choice for nonmetal implants. This article introduces the reader to zirconia as an implant material, its properties, manufacturing processes, and the particular surface modifications and treatments that have rendered its surfaces biologically compatible with peri-implant soft and hard tissues.

In materials selection, a decision matrix method refers to any formalized procedure by which materials are ranked prior to a selection decision. This article describes the advantages and limitations of decision matrix methods, as well as the steps involved, with examples. The methods include the Pugh method, the Dominic method, and the Pahl and Beitz method. The article discusses the three important concepts in decision making: alternatives (candidate materials), criteria (objectives), and weighting factors.

This article describes the principal cladding processes and methods for calculating properties of clad metals. It reviews the designing processes of clad metals to achieve specific requirements. The article discusses six categories of clad metal systems designed for corrosion control: noble metal clad systems, corrosion barrier systems, sacrificial metal systems, transition metal systems, complex multilayer systems, and clad diffusion alloys.

This article describes the failure characteristics of high-pressure long-distance pipelines. It discusses the causes of pipeline failures and the procedures used to investigate them. The use of fracture mechanics in failure investigations and in developing remedial measures is also reviewed.

This article provides an overview of some common sheet steel coatings available. It discusses the formability differences between coated and bare steel and provides some general guidelines on the forming of coated steels. Coated steels are classified according to the nature of the substrate, the type of coating, and the method used for its application. The article describes various coating types for steels such as zinc-coated steels, aluminum-coated steels, tin-coated steels, terne-coated steels, and organic-coated steels.

This article discusses the composition, properties and applications of bearing steels. It focuses on the typical wear modes that rolling-element bearings experience: contact fatigue wear, abrasive wear, adhesive wear, and corrosive wear. The article provides information on reliability factor and ABMA and ISO environmental factors.

The mechanism of contact fatigue can be understood in terms of several sources of stress concentration, or stress raisers, within the macroscopic Hertzian stress field. This article focuses primarily on rolling contact fatigue of hardened bearing steels. It discusses Hertzian shear stresses at and below the contact surfaces and briefly summarizes bearings and gear characteristics. The article provides an overview of the key types of gear and bearing steels. It analyzes two types of macropitting that result from the subsurface growth of fatigue cracks, namely, subsurface-origin macropitting and surface-origin macropitting. The article describes the factors influencing contact fatigue life of hardened steel bearings and gears, including hardness, inclusions, carbides, and residual stresses.

This article discusses the main materials and water chemistry characteristics of the primary and secondary water circuits of a pressurized water reactor (PWR). It reviews the corrosion issues of PWR materials and the influence of corrosion and fouling on primary and secondary circuit radiation fields. The article explains the primary side intergranular stress corrosion cracking (IGSCC) in different materials, namely, nickel-base alloys, high-strength nickel-base alloys, low-strength austenitic stainless steels, and high-strength stainless steels. The secondary side corrosion in steam generator including denting, pitting, intergranular attack and IGSCC is also discussed. The article examines laboratory studies that have resulted in models and computer codes for evaluating and predicting intergranular corrosion, and considers the remedial actions for preventing or arresting intergranular corrosion. It concludes with information on the external bolting corrosion in nuclear power reactors.

There are many different types of polymeric materials, ranging from glassy to semicrystalline polymers and even blends. Their mechanical properties range from pure elastic with very high strains to fracture (elastomers) to almost pure linear elastic (Hookian behavior) with low strains to fracture (glassy polymers). This article provides an overview of historical development of fracture behavior in polymers. It discusses the processes involved in three fracture test methods for polymers, namely linear elastic fracture mechanics, elastic-plastic fracture mechanics, and post-yield fracture mechanics.

Rolling-element bearings use rolling elements interposed between two raceways, and relative motion is permitted by the rotation of these elements. This article presents an overview of bearing materials, bearing-load ratings, and an examination of failed bearings. Rolling-element bearings are designed on the principle of rolling contact rather than sliding contact; frictional effects, although low, are not negligible, and lubrication is essential. The article lists the typical characteristics and causes of several types of failures. It describes failure by wear, failure by fretting, failure by corrosion, failure by plastic flow, failure by rolling-contact fatigue, and failure by damage. The article discusses the effects of fabrication practices, heat treatment and hardness of bearing components, and lubrication of rolling-element bearings with a few examples.

This datasheet provides information on composition limits, fabrication characteristics, processing effects on physical and mechanical properties, and applications of bright-finishing alloys 5457, 5557, and 5657. A table lists approximate bend radii for 90 deg cold bending of alloy 5557.

This article addresses the issue of the implementation of composite damage tolerance requirements as it relates to military aircraft. It presents a brief introduction on the durability impact threat, damage tolerance impact threat, and other damage tolerance damage threats. The article summarizes damage tolerance criteria and durability criteria for military aircraft. It discusses the damage tolerance design philosophy for metallic structures and composite structures of the aircraft. The article describes the implementation of a damage tolerance analysis methodology in terms of the mechanics based model, the regression algorithm, and the semi-empirical analysis.

As with most engineering materials, the failure of composite materials, no matter how complex, can be divided into three discrete arenas: improper design, improper manufacturing, and improper use of the end product. This article reviews the failure causes from a broad perspective, so that the composites designer, manufacturer, and user can readily see some of the more common issues associated with unique materials. It discusses the three discrete arenas of failure of composite materials: improper design, improper manufacturing, and improper use of the end product.