The tensile test provides a relatively easy, inexpensive technique for developing mechanical property data for the selection, qualification, and utilization of metals and alloys in engineering service. The tensile test requires interpretation, and interpretation requires a knowledge of the factors that influence the test results. This chapter provides a metallurgical perspective for such interpretation. The topics covered include elastic behavior, anelasticity, damping, proportional limit, yield point, ultimate strength, toughness, ductility, strain hardening, and yielding and the onset of plasticity. The chapter describes the effects of grain size on yielding, effect of cold work on hardness and strength, and effects of temperature and strain-rate on the properties of metals and alloys. It provides information on true stress-strain relationships and special tests developed to measure the effects of test/specimen conditions. Finally, the chapter covers the characterization of tensile fractures of ductile metals and alloys.

This article describes the general aspects of and practical problems of failure analysis of creep, stress relaxation, and yielding for homogeneous polymers. The effect of temperature and strain rate on the relationship between yield point and elastic modulus and the aging effect that polymers often undergo at room temperature are also discussed.

When a metal is alloyed with another metal, either substitutional or interstitial solid solutions are usually formed. This chapter discusses the general characteristics of these solutions and the effects of several alloying elements on the yield strength of pure metals. It presents four rules that give a qualitative estimate of the ability of two metals to form substitutional solid solutions: relative size factor, chemical affinity factor, relative valency factor, and lattice type factor. The chapter provides information on alloys that form an ordered structure during heating. It describes the intermediate phases that are formed during solidification between the two extremes of substitutional solid solution on the one hand and intermetallic compound on the other. The chapter concludes with a section on strain aging in low-carbon steels that allows the interstitial atoms to diffuse to the dislocations and again form atmospheres that pin dislocation movement.

This chapter is a detailed account of the tensile testing procedure used for evaluating metals and alloys. The discussion covers the stress-strain behavior of metals determined by tensile testing, properties determined from testing, test machines for measuring mechanical properties, and general procedures of tensile testing. Three distinct aspects of standard test methods for tension testing of metallic materials are discussed: test piece preparation, geometry, and material condition; test setup and equipment; and test procedure.

This chapter focuses on tensile testing of three types of engineering components that undergo significant loading in tension, namely, threaded fasteners and bolted joints; adhesive joints; and welded joints. It describes the standardized tensile test for externally threaded fasteners and provides a brief background on relationships among torque, angle-of-turn, tension, and friction. The chapter also describes the test methods covered in the ASTM F 606M standard, namely, product hardness; proof load by length measurement, yield strength, or uniform hardness; axial tension testing of full-sized products; wedge tension testing of full-sized products; tension testing of machined test specimens; and total extension at fracture testing. Finally, the chapter covers tensile testing of adhesive and welded joints.

Product design requires an understanding of the mechanical properties of materials, much of which is based on tensile testing. This chapter describes how tensile tests are conducted and how to extract useful information from measurement data. It begins with a review of the different types of test equipment used and how they compare in terms of loading force, displacement rate, accuracy, and allowable sample sizes. It then discusses the various ways tensile measurements are plotted and presents examples of each method. It examines a typical load-displacement curve as well as engineering and true stress-strain curves, calling attention to certain points and features and what they reveal about the test sample and, in some cases, the cause of the behavior observed. It explains, for example, why some materials exhibit discontinuous yielding while others do not, and in such cases, how to determine when yielding begins. It also explains how to determine other properties via tensile tests, including ductility, toughness, and modulus of resilience.