Search Results for interfacial wear

Plastics or polymers are used in a variety of engineering and nonengineering applications where they are subjected to surface damage and wear. This article discusses the classification of polymer wear mechanisms based on the methodologies of defining the types of wear. The first classification is based on the two-term model that divides wear mechanisms into interfacial and bulk or cohesive. The second is based on the perceived wear mechanism. The third classification is specific to polymers and draws the distinction based on mechanical properties of polymers. In this classification, wear study is separated as elastomers, thermosets, glassy thermoplastics, and semicrystalline thermoplastics. The article describes the effects of environment and lubricant on the wear failures of polymers. It presents a case study on nylon as a tribological material. The article explains the wear failure of an antifriction bearing, a nylon driving gear, and a polyoxymethylene gear wheel.

This article presents the mechanisms of polymer wear and quantifies wear in terms of wear rate (rate of removal of the material). Interfacial and bulk wear are discussed as well as a discussion on the wear study of "elastomers," "thermosets," "glassy thermoplastics," and "semicrystalline thermoplastics." The article also discusses the effects of environment and lubricant on the wear failures of polymers. It presents a case study on considering nylon as a tribological material and failure examples, explaining wear resistance of polyurethane elastomeric coatings and failure of an acetal gear wheel.

This article describes the laboratory techniques for direct measurement and quantification of die wear in verifying a proprietary die-wear predictor methodology. This method is based on a theoretical formula that can be used to predict the rate of die wear and the life of a die surface coating, applicable to both mild steel and high-strength steels stampings. The article discusses the behavior of the surface conditions through quantitative measurements and surface analyses conducted throughout the wear tests. The surface conditions include surface roughness, surface morphology, microstructure, interfacial friction, surface temperatures, and wear rate.

Transition metal dichalcogenides (TMD) are solid lubricant materials, specifically, intrinsic solid lubricants, whose crystal structure facilitates interfacial sliding/shear to achieve low friction and wear in sliding contacts and low torque in rolling contacts. This article provides information on sliding friction and wear behavior of unbonded, bonded, and vapor-deposited pure and composite MoS 2 and WS 2 coatings. It discusses the rolling-torque behavior and applications of vapor-deposited pure and composite MoS 2 and WS 2 coatings. The article concludes with information on various forms of TMD lubrication, namely, oils, greases, microparticle and nanoparticle additives.

Tribology is the science and technology of interacting surfaces in relative motion. This article describes in detail the basic structural, operational, and interaction parameters of a tribosystem. The interaction parameters, which characterize the action of the operational parameters on the structural components in the system, consist of three important aspects: contact parameters, friction parameters, and wear parameters. These three aspects embody the complex mechanisms and relationships between the constituents of a tribosystem. The article concludes with information on the selection criteria of a material for wear applications.

This article discusses the adhesion behavior of materials in low-pressure and vacuum environments and provides a schematic illustration of an apparatus for measuring adhesion and friction in ultrahigh vacuum. It describes the effects of low-oxygen pressures and vacuum environments on adhesion and friction, as well as the effects of defined exposure to oxygen on friction. The article discusses the wear of various metals in contact with ceramics, and alloying element effects on friction, wear, and transfer of materials. It also describes studies that characterize the contributions of surface contamination and chemical changes to tribology in low-pressure and vacuum environments.

The influence of friction and wear on the function and structure of tribological systems is determined by various types of tribological tests. This article introduces the general categories of tribological testing and describes the basic objectives of testing. It reviews the results of tribological tests, where the system-dependent characteristics of friction and wear data can be expressed in different forms, such as tribographs, transition diagrams, and tribomaps. A summary of various methods of surface analysis is presented in a table. The article discusses the relationship between wear and reliability in terms of exponential distribution, Weibull distribution, and gamma distribution. It concludes with information on the effects of interaction on failure probability.

Reinforced polymers (RPs) are widely used in structural, industrial, automotive, and engineering applications due to their ecofriendly nature and the potential to manipulate their properties. This article addresses the technical synthesis of RPs, referring to their tribological behavior, to provide insights into the contribution and interaction of influential parameters on the wear behavior of polymers. It provides a brief discussion on the effects of significant parameters on RP tribology. The article describes abrasive and adhesive wear and provides a theoretical synthesis of the literature regarding the wear mechanisms of RPs. It also describes the synthesis of abrasive wear failure of different types of RPs and highlights the contribution of these influential parameters. The article addresses the synthesis of adhesive wear failure of different types of RPs.

This article focuses on ceramics, glasses, glass-ceramics, and their derivatives, that is, inorganic-organic hybrids, in the forms of solid or porous bodies, oxide layers/coatings, and particles with sizes ranging from nanometers to micrometers, or even millimetres. These include inert crystalline ceramics, porous ceramics, calcium phosphate ceramics, and bioactive glasses. The article discusses the compositions of ceramics and carbon-base implant materials, and examines their differences in processing and structure. It describes the chemical and microstructural basis for their differences in physical properties, and relates the properties and hard-tissue response to particular clinical applications. The article also provides information on the glass or glass-ceramic particles used in cancer treatments.

Corrosive wear is defined as surface damage caused by wear in a corrosive environment, involving combined attacks from wear and corrosion. This article begins with a discussion on several typical forms of corrosive wear encountered in industry, followed by a discussion on mechanisms for corrosive wear. Next, the article explains testing methods and characterization of corrosive wear. Various factors that influence corrosive wear are then covered. The article concludes with general guidelines for material selection against corrosive wear.

This article discusses the tests designed specifically to evaluate the adhesion, friction, and wear behavior of various material systems. It tabulates the characteristics of common types of wear and mechanical surface damage. The article also considers the displaying and analyzing of adhesion, friction, and wear test data. It concludes with a description of devices used for testing adhesion, friction, and wear.

This article reviews the abrasive and adhesive wear failure of several types of reinforced polymers, including particulate-reinforced polymers, short-fiber reinforced polymers (SFRP), continuous unidirectional fiber reinforced polymers (FRP), particulate-filled composites, mixed composites (SFRP and particulate-filled), unidirectional FRP composites, and fabric reinforced composites. Friction and wear performance of the composites, correlation of performance with various materials properties, and studies on wear-of failure mechanisms by scanning electron microscopy are discussed for each of these types.

This article describes measurement techniques for the three basic types of adhesion: fundamental adhesion, thermodynamic adhesion, and practical adhesion. It discusses common measurement methods for each type of adhesion with the main focus on practical adhesion testing of coatings and thin films. The article provides an insight into the mechanisms of environmentally induced interfacial degradation by discussing the fundamental aspects of adhesion between two dissimilar materials. It examines the use of adhesion tests in the evaluation of stress-corrosion cracking within bimaterial interfaces. Testing techniques for <i>in situ</i> environmental testing of thin-film adhesion are also reviewed.