资料物理2(国外英文资料).docVIP

材料物理2(国外英文资料) Fill in the blanks. Noun explanation Phonon: the energy quantum of a single harmonic oscillator in lattice vibrations. The characteristic of gebo: its media is not a connected medium. Its a lattice of yards, ions, etc. The vibration mode of the lattice: the thermal vibration of the atom at the point of the lattice is described as the result of a mechanical wave propagation, called a grabo. Micro cracks Griffith theory: Griffith think actually always exist many tiny cracks or defects in materials, under the action of external force, these can produce stress concentration phenomenon near the crack and defect, when the stress reaches a certain degree, the crack begins to expand and cause fracture. This is the famous microcrack theory of Griffith. The mechanism of particle reinforced materials: is that particles can prevent the dislocation movement inside the substrate, or energy through plastic deformation and absorb part of the particles, so as to achieve the purpose of strengthening. Complex of thermal expansion hysteresis causes: due to different phase in different direction, or grain expansion coefficient difference is very big, have a lot of stress, make the body produces micro cracks. Crack extension there are several types: (1) open the type is the main reason for the low stress fracture 】 【 (Zhang Kaihang, type I), (2) the staggered type (slides open type, type II) (3) tore open sex (III) : the nature of thermal breakdown in the electric field of dielectric, due to the dielectric loss heating, when the applied voltage is high enough, may from the thermal equilibrium state of cooling and heating load imbalance. If the energy is greater than the dispersed, the temperature of the medium will be higher and higher until there is permanent damage. Carrier in the conductive material: any kind of material, as long as there is a charged free particle, which can be generated under the effect of electric field to store the current [carrier is free electrons