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Unary Phase Diagram

Phase diagrams are important and essential tools to understand compositional concentrations of two or more elements. These are influenced by temperature and pressure. Melting point of tungsten is 3400°C and that of aluminum 657°C, hence the two elements cannot blend together as their solid-liquid or intermediate phases restrict them to do so. However melting point …

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Interstitial | Substitutional Solid Solution

Materials are transformed into various phases under the effects of temperature and pressure. The iron is available in BCC form (α-iron), FCC form (y-iron) and BCC form again (δ-iron) at certain temperatures. The development of alloys, whether non-ferrous brass or ferrous high speed steel (H.S.S.); magnetic alnico or antifriction babbits, require the knowledge of solid …

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Destructive Tests of Materials

In order to determine the mechanical properties of materials certain tests are carried-out. Depending on the nature of tests, these are classified as follows: Non-destructive tests (NDT) in which the materials or their specimens are not broken. Destructive tests in which the specimens of materials are fractured or deformed. Destructive Tests Generally specimens are tested …

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Non-destructive Testing Methods

The non-destructive testing (NDT) refers to a method of detecting internal flaws in engineering materials, machine components, and structures without breaking them. These tests are essential to ascertain absolute safety and reliability in engineering applications: particularly in strategic industries such as atomic energy, missiles, defense, aeronautics, space etc. The non-destructive testing techniques can be employed …

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Fatigue in Materials

Definition: The behavior of materials under fluctuating and reversing loads (or stresses) is known as fatigue. This behavior is different from that under the steady load. Fatigue is, however, not a dynamic effect. The rate of loading is usually not a factor in fatigue behavior. Fatigue behavior is experienced by all materials whether metals, plastics, …

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Screw | Edge dislocation in Crystalline Solids

Line imperfections are called dislocations. There are two primary types of dislocations. These are: Edge dislocation, and Screw dislocation. Edge Dislocations To understand an edge dislocation, consider a perfect crystal shown in Figure 1(a). Atoms (not shown in diagram) are located on each cross-point in it. A perfect crystal is free from dislocations. Now consider …

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