Search Results for durometer hardness testing

This chapter reviews the tests and procedures used for measuring hardness of plastics and elastomers. The conventional testing methods (Rockwell, Vickers, Brinell, and Knoop) used for testing of metals are based on the idea that hardness represents the resistance against permanent plastic deformation of the material to be tested. However, elastic deformation must be considered in hardness measurement of elastomers. This chapter discusses the equipment and processes involved in the durometer (Shore) test, the International Rubber Hardness Degree test, and other specialized tests. It presents the criteria that can be used to select a suitable hardness testing method for elastomers or plastics and describes processes involved in specimen preparation and equipment calibration.

This article briefly introduces some commonly used methods of mechanical testing of plastics for determining mechanical properties, also describing the test methods and providing comparative data for the mechanical property tests. In addition, creep testing and dynamic mechanical analyses of viscoelastic plastics are briefly described. The discussion covers the most commonly used tests for impact performance, various types of hardness test for plastics, the fatigue strength of viscoelastic materials, and the tension testing of elastomers and fibers.

Elastomers comprise a subclass of polymers that display the ability to stretch and recover that is typical of a rubber band. This chapter describes the properties determined by tensile testing of elastomers and the factors influencing them, namely, structuring of the molecular matrix, compounding, specimen preparation, specimen type, vulcanization parameters, and temperature. The chapter also provides information on ASTM D 412, the most widely referenced standard for determining the tensile properties of elastomers.

This chapter discusses the effect of friction in the context of design. It explains how friction coefficients are determined and how they are used to make sizing and selection decisions. It covers practical issues associated with rolling friction, the use of lubricants, and the tribology of metal, ceramic, and polymer surfaces in contact. It also discusses the nature of rolling friction and provides helpful design guidelines.

This chapter provides the definitions of fundamental wear mechanisms. The chapter describes the properties and applications of materials used for wear resistance. It discusses the processes involved in screening tests for wear resistance. In addition, the practical application of wear-resistant principles is covered.

This chapter discusses the processes and procedures involved in tribotesting, the significance of test parameters and conditions, and practical considerations including test metrics and measurements and the interpretation of wear damage. It also describes the different types of erosion tests in use and common approaches for adhesive wear and abrasion testing.

This appendix provides supplemental information on the metallurgical aspects of atomic structure, the use of dislocation theory, heat treatment processes and procedures, important engineering materials and strengthening mechanisms, and the nature of elastic, plastic, and creep strain components. It also provides information on mechanical property and fatigue testing, the use of hysteresis energy to analyze fatigue, a procedure for inverting equations to solve for dependent variables, and a method for dealing with the statistical nature of failure.

This chapter reviews the types of friction that are of concern in tribological systems along with their associated causes and effects. It discusses some of the early discoveries that led to the development of friction laws and the understanding that friction is a system effect that can be analyzed based on energy dissipation. It describes the stick-slip behavior observed in wiper blades, the concept of asperities, and the significance of the shape, lay, roughness, and waviness of surfaces in sliding contact. It explains how friction forces are measured and how they are influenced by speed, load, and operating environment. It also covers rolling contact and fluid friction and the effect of lubrication.

All materials are susceptible to corrosion or some form of environmental degradation. Although no single material is suitable for all applications, usually there are a variety of materials that will perform satisfactorily in a given environment. The intent of this chapter is to review the corrosion behavior of the major classes of metals and alloys as well as some nonmetallic materials, describe typical corrosion applications, and present some unique weaknesses of various types of materials. It also aims to point out some unique material characteristics that may be important in material selection, and discuss, where appropriate, the characteristic forms of corrosion that attack specific materials. The materials addressed in this chapter include carbon steels, weathering steels, and alloy steels; nickel, copper, aluminum, titanium, lead, magnesium, tin, zirconium, tantalum, niobium, and cobalt and their alloys; polymers; and other nonmetallic materials, including rubber, carbon and graphite, and woods.

This chapter describes sheet metal forming operations, including cutting, blanking, piercing, and bending as well as deep drawing, spinning, press-brake and stretch forming, fluid forming, and drop hammer and electromagnetic forming. It also discusses the selection and use of die materials and lubricants along with superplastic forming techniques.

This chapter presents several materials and processes related to soldering technology. It first provides information on lead-free solders, followed by sections devoted to flip-chip processes, diffusion soldering, and modeling. Scanning acoustic microscopy and fine-focus x-ray techniques are also discussed. The chapter describes several evaluation procedures and tests developed to measure solderability and standards for process calibration. The chapter also describes the characteristics of reinforced solders, amalgams used as solders, and other strategies to boost the strength of solders. Further, the chapter considers methods for quantifying the mechanical integrity of joints and predicting their dimensional stability under specified environmental conditions. It discusses the effects of rare earth elements on the properties of solders. The chapter concludes with information on advanced joint characterization techniques.