Electromagnetic testing emt-mft chapter 9b

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Curie temperature In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature where a material's permanent magnetism changes to induced magnetism. The force of magnetism is determined by magnetic moments. The Curie temperature is the critical point where a material's intrinsic magnetic moments change direction. Magnetic moments are permanent dipole moments within the atom which originate from electrons' angular momentum and spin. Materials have different structures of intrinsic magnetic moments that depend on temperature. At a material's Curie Temperature those intrinsic magnetic moments change direction. Permanent magnetism is caused by the alignment of magnetic moments and induced magnetism is created when disordered magnetic moments are forced to align in an applied magnetic field. For example, the ordered magnetic moments (ferromagnetic, figure 1) change and become disordered (paramagnetic, figure 2) at the Curie Temperature. Higher temperatures make magnets weaker as spontaneous magnetism only occurs below the Curie Temperature. Magnetic susceptibility only occurs above the Curie Temperature and can be calculated from the Curie- Weiss Law which is derived from Curie's Law. In analogy to ferromagnetic and paramagnetic materials, the Curie temperature can also be used to describe the temperature where a material's spontaneous electric polarisation changes to induced electric polarisation or the reverse upon reduction of the temperature below the Curie temperature. Charlie Chong/ Fion Zhang http://en.wikipedia.org/wiki/Curie_temperature
Curie temperature Below T c Ferromagnetic Ferrimagnetic Antiferromagnetic Above T c ↔ Paramagnetic ↔ Paramagnetic ↔ Paramagnetic Charlie Chong/ Fion Zhang http://en.wikipedia.org/wiki/Curie_temperature
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Electromagnetic Testing MFLT/ ECT/
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Ship building Charlie Chong/ Fion Z
Page 5 and 6: Offshore Structures & Appurtenances
Page 13 and 14: Power Piping Charlie Chong/ Fion Zh
Page 15 and 16: Charlie Chong/ Fion Zhang
Page 17 and 18: Fion Zhang at Shanghai 2015 Februar
Page 19 and 20: Chapter 9B: Magnetic Field Testing
Page 21 and 22: Keywords: Field of magnetic materia
Page 23 and 24: Although it is conceivable that lea
Page 25 and 26: Barkhausen noise: Magnetization (J)
Page 27 and 28: Barkhausen noise A coil of wire wou
Page 29 and 30: A set-up for non-destructive testin
Page 31 and 32: Magnetic Dipole Charlie Chong/ Fion
Page 33 and 34: If a slot is cut in the rod, as ill
Page 35 and 36: 2.2 Experimental Techniques. One of
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Page 41 and 42: Fig. 3 Flux leakage measurement usi
Page 43 and 44: Unlike the inductive coil, which pr
Page 45 and 46: There are, however, many situations
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Page 49 and 50: Fig. 6 Characterization of a ferrit
Page 51 and 52: PART 2. Principles of Magnetic Char
Page 53 and 54: Hysteresis Curves Charlie Chong/ Fi
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Page 59 and 60: Paramagnetism The magnetic moments
Page 61 and 62: Antiferromagnetism The magnetic mom
Page 63 and 64: Fig. 7 Experimental arrangement for
Page 65 and 66: The review articles and conference
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Page 69 and 70: In addition to systems for inspecti
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Page 73 and 74: Another area in which the flux leak
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Page 79 and 80: Fig. 10 Effect of mechanical hardne
Page 81 and 82: Keywords: • For one alloy, AISI 4
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Page 85 and 86: VLCC Charlie Chong/ Fion Zhang
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Page 89 and 90: Pipeline & Piping Charlie Chong/ Fi
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Electromagnetic testing emt-mft chapter 9b

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