Search Results for single-component systems

This chapter explains how the principles of chemical thermodynamics are used in the construction and interpretation of phase diagrams. After a brief review of the laws of thermodynamics, it describes the concept of Gibbs free energy and its application to transformations that occur in single-component and binary solid solutions. It then examines the relationship between the free energy of a solution and the chemical potentials of the individual components. It also explains how to account for the heat of mixing using quasi-chemical models, discusses the effect of interatomic bond energies and chemical potentials, and shows how the equilibrium state of an alloy can be obtained from free-energy curves.

This chapter describes the physical characteristics, properties, and behaviors of solid solutions under equilibrium conditions. It begins with a review of a single-component pure metal system and its unary phase diagram. It then examines the solid solution formed by copper and nickel atoms. It discusses the difference between interstitial and substitutional solid solutions and the factors that determine the type of solution that two metals are likely to form. It also addresses the development of intermediate phases, the role of free energy, transformation kinetics, liquid-to-solid and solid-state phase transformations, and the allotropic nature of metals.

In order to understand how various types of single-load fractures are caused, one must understand the forces acting on the metals and also the characteristics of the metals themselves. All fractures are caused by stresses. Stress systems are best studied by examining free-body diagrams, which are simplified models of complex stress systems. Free-body diagrams of shafts in the pure types of loading (tension, torsion, and compression) are the simplest; they then can be related to more complex types of loading. This chapter discusses the principles of these simplest loading systems in ductile and brittle metals.

In embedded systems, the separation between system level, board level, and individual component level failure analysis is slowly disappearing. In order to localize the initial defect area, prepare the sample for root cause analysis, and image the exact root cause, the overall functionality has to be maintained during the process. This leads to the requirement of adding additional techniques that help isolate and image defects that are buried deeply within the board structure. This article demonstrates an approach of advanced board level failure analysis by using several non-destructive localization techniques. The techniques considered for advanced fault isolation are magnetic current imaging for shorts and opens; infrared thermography for electrical shorts; time-domain-reflectometry for shorts and opens; scanning acoustic microscopy; and 2D/3D X-Ray microscopy. The individual methods and their operational principles are introduced along with case studies that will show the value of using them on board level defect analysis.

The load-displacement capabilities of a mechanical press are determined largely by the design of its drive mechanism or, more precisely, the linkage through which the drive motor connects to the slide. This chapter discusses the primary types of linkages used and their effect on force, velocity, and stroke profiles. It begins by describing the simplest drive configuration, a crankshaft that connects directly to the slide, and a variation of it that uses eccentric gears to alter the stroke profile. It then discusses the effect of adding a fixed link, knuckle joint, or toggle to the slider-crank mechanism and how gear ratios, component arrangements, and other design parameters affect slide motion. The chapter also explains how to assess load and energy requirements, time-dependent characteristics, and dimensional accuracy and discusses overload protection, shutheight adjustment, and slide counterbalancing as well.

This appendix provides a brief introduction to Thermo-Calc, explains what it is, and lists its uses. Instructions for accessing a demonstration version of the software are also provided.

This chapter discusses the unique characteristics of isomorphous alloy systems. It begins with a review of the naming conventions for multi-component systems and the construction of a three-dimensional phase diagram for a two-component alloy system. It explains how phase diagrams can be constructed from time-temperature cooling curves and how they can be used to predict the phases present, their chemical compositions, and relative amounts. It also shows how phase diagrams can be modified to account for nonequilibrium cooling conditions.

This chapter covers special fault-tree analysis topics, including the use of transfer symbols, INHIBIT gates, sequential AND gates, state-of-the-part versus state-of-the-system considerations, and the fault tree to identify redundancy-defeating failures.

This chapter describes important aspects of the interrelationship between the workpiece and the inductor coil, an understanding of which is essential for achieving an efficient soldering process and a solder joint with the desired performance and reliability. It also discusses induction soldering machine operation parameters, including temperature measurement and control sensors. The chapter illustrates the equipment used in a fully automated induction heating system. Fully automated soldering systems include temperature monitoring devices to control the temperature-time profile, the movement of workpieces, the supply of solder filler metal and flux, and the provision of shielding gas in the solder joint area.

This chapter discusses some of the methods and measurements used to construct phase diagrams. It explains how cooling curves were widely used to determine phase boundaries, and how equilibrated alloys examined under controlled heating and cooling provide information for constructing isothermal and vertical sections as well as liquid projections. It also explains how diffusion couples provide a window into local equilibria and identifies typical phase diagram construction errors along with problems stemming from phase-boundary curvatures and congruent transformations.

Fault-tree analysis is a graphical technique that identifies all events and combinations of events that can produce an undesired event. This chapter emphasizes several fault-tree analysis concepts, examining with examples how all three categories of charting symbols (events, gates, and transfer symbols) come together to generate a fault-tree analysis.

The relationship of stress and strength gradients must be considered simultaneously in analysis of a particular type of fracture. This chapter discusses the principal elastic stress distribution in members of various shapes under different types of pure loads. A basic understanding of both the stress and strength gradients of metal parts with and without stress concentrations and under different types of loading is provided. The chapter also describes the effect of service conditions on applied stresses.

In this chapter, the fundamental concepts of different types of extrusion presses and major press components are discussed. An outline of the recently integrated system, from billet furnaces and log shears to age ovens and stacking equipment to control the entire manufacturing process with high productivity, is also included. The major press and tooling components of basic types of extrusion presses for making solid sections, bars, strips, rods, tubes, and hollow sections are shown. Auxiliary and handling equipment is discussed.

Adhesive bonding is a widely used industrial joining process in which a polymeric material is used to join two separate pieces (the adherends or substrates). This chapter begins with a discussion on the advantages and disadvantages of adhesive bonding, followed by a section providing information on the theory of adhesion. The chapter then describes the considerations for designing adhesively bonded joints and for testing or characterizing adhesive materials. The following section covers the characteristics of the most important synthetic adhesive systems and five groups of adhesives, namely structural, hot melt, pressure sensitive, water based, and ultraviolet and electron beam cured. The chapter ends with a discussion on some general guidelines for adhesive bonding and the basic steps in the adhesive bonding process.

This chapter focuses on what can cause a system to fail and addresses the challenge in approaching a system failure. It then examines the steps involved in the four-step problem-solving process: defining the problem, identifying all potential failure causes and evaluating the likelihood of each, identifying the potential solutions, and identifying the best solution. The chapter concludes by describing the responsibilities of a failure analysis team.

This chapter provides a discussion on the power supplies of modern induction heating plants. It describes the mode of operation and functional principle of an inverter. The chapter also provides a short note on generator cooling, which is required for the components of the induction power supply. It then presents an overview of induction heating systems.

This chapter discusses the ways in which the evolution of filament winding software systems has capitalized on the inherent flexibility of computer numerical controlled winding machines and enhanced their productivity. It provides a detailed discussion on different types of geometries that can be wound, from the simple to the highly complex, with insight into the limitations, advantages, and challenges of each. Components covered include classic axisymmetric parts (rings, pipes, driveshafts, pipe reducers, tapered shafts, closed-end pressure vessels, and storage tanks), nonround sections (aeromasts, airfoils, box sections, and fuselage sections), curved-axis parts (elbows, ducts), and special applications (tees). Basic winding concepts, such as band pattern, are discussed and explained, and some simple predictive formulae are introduced. The chapter also provides examples of programming various geometries using advanced software tools and discusses how various materials, such as rovings, tow-preg, prepreg tape, and woven materials, affect winding program generation.

This chapter provides an overview of the physical metallurgy of beryllium, discussing phases and phase transformations, physical and mechanical properties, heat treatment, and alloying. It explains how the atomic structure of beryllium, particularly its sp hybrid state, contributes to the anisotropy of elastic constants and slip properties, resulting in a specific stiffness, or modulus-to-density ratio, six times higher than that of any other structural material.

A system failure occurs when a system does not do what it is supposed to do when it is supposed to do it, or it does something it is not supposed to do. This chapter provides a basic understanding of how failures occur, how systems operate, and the types of failures, namely intermittent and inadvertent system failures.

Phase diagrams are graphical representations that show the phases present in the material at various compositions, temperatures, and pressures. This chapter begins with a section describing the construction of phase diagrams for the simple binary isomorphous system. A binary phase diagram can be used to determine three important types of information: the phases that are present, the composition of the phases, and the percentages or fractions of the phases. The chapter then describes the construction of one common type of binary phase diagram i.e., the eutectic alloy system. The major eutectic systems include the aluminum-silicon eutectic system and the lead-tin eutectic system. The chapter discusses the construction of eutectic phase diagrams from free energy curves. It also provides information on peritectic, monotectic, and solid-state reactions in alloy systems. The presence of intermediate phases is also described. Finally, a brief section provides some information on ternary phase diagrams.