1. Classification y Ideal or perfect crystal real or defect crystal According to dimension o point defect: vacancies, interstitial atoms s line defect dislocation planar defect: stacking fault o volume defect mosaic structure

4.9 Comparison Between Slip and Twinning Similar ity Both slip and twinning are shear process under shear stress T I. Differences 1. Orientation 2. Atom movement 3.y,△ a) Structure: Twinning is easy 4. Conditions b) Temperature da d c) Strain rate (c

4. Rule for elongation or reduction of R D All R.D. in the region where K1 and K2 makes an obtuse(acute) angle will increase (reduce) its length after twinning

1. The cause of rotation: Due to constraints, or boundary conditions imposed on the crystal. ll. The rule of rotation:

3. Application of Schmid's law How to determine the active S.S. for all the equivalent S.S. 2 Determine the active S.S. by Reflection Rule. Orientation cell for cubic crystals. Given: BCC Crystal having {110}slip system. Determine: active slip system in response to tensile loading along

1. Deformation process of polycrystalline materials Deformation process of industrial material consists of three stages Elastic. which is reversible

I Introduction Silicates are compounds that mainly composed of [sio4]. It is the essential components of most rock and soil, such as quartz, feldspar, mica etc

Paulings three rules governing the structure of ionic compounds 1. Anion Coordination polyhedron rule Each cation is surrounded by an anion polyhedron, the distance between anion and cation is r=rt tr, while the cn depends on rt/r

1. The structure of am b differs from those of either a or B 2. Its composition is variable to more or lessextension 3. Mixed bonding 4. Intermediate properties

1. Sing le crystal ver sus po l crystal 1. For single crystals there is only one type of structure with same orientation Single crystals is characterized by anisotropy 2. Polycrystal consists of a lot of grain, small single crystals, With same structure but different orientations. These small single crystals are called grains. The boundaries between them are called grain boundaries