Grain Structure by Tarun https://padlet.com/tarun_mudhar/grainstructure YR13 Padlet Assignment en-us 2018-10-11 09:15:46 UTC 2023-01-23 03:58:18 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Balance.png Padlet assignment tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291619149 Design and produce a padlet page (with as many links as you see fit) in order to produce a teaching tool on the topic "Grain structure and slip planes". Use the assignment sheet attached as a guide. Use diagrams to add clarity and any youtube videos or other resources you think are relevant. Add your page to this padlet before next lesson.]]> 2018-10-11 09:22:52 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291619149 Crystal structure Lattices tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291619379 As atoms of a pure metal cool, they start to form crystalline lattice structures]]> 2018-10-11 09:23:25 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291619379 Body-Centred cubic(BCC) tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291620450 2018-10-11 09:26:38 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291620450 3 most common lattice structures tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291620644 2018-10-11 09:27:19 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291620644 Face-Centred Cubic(FCC) tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291621501 2018-10-11 09:29:34 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291621501 Hexagonal Close-Packed (HCP) tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291621852 2018-10-11 09:30:35 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291621852 Grain Structure tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291622344 2018-10-11 09:32:04 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291622344 What is a metal grain? tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291623094 These crystals form the grains in the solid metal. Each grain is a distinct crystal with its own orientation. The areas between the grains are known as grain boundaries. Within each grain, the individual atoms form a crystalline lattice.]]> 2018-10-11 09:34:24 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291623094 How does it form? tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291623391 Within each grain, the individual atoms form a crystalline lattice. Each atom will have a certain number of close neighbours with which it shares loose bonds. (The number of neighbouring atoms depends upon the structure of the lattice.) When stress is applied to the metal, the atoms will start to spread apart. The atomic bonds stretch, and the attractive forces between the atoms will oppose the applied stress, like millions of tiny springs. If the metal has not yielded, the inter atomic forces will pull the metal back into its original shape when the stress is removed.]]> 2018-10-11 09:35:22 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291623391 What is a grain boundary? tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291624363 the interface between two grains, or crystallises, in a poly crystalline material. Grain boundaries are defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material.]]> 2018-10-11 09:38:39 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291624363 What macroscopic effects might take place at a grain boundary? tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291625036 Hydrogen diffusion through a 2D heterogeneous poly crystalline micro structure is simulated.
Each grain boundary is assigned one of two different diffusivities, while the grains have the same diffusivity.
The grain-boundary networks clustering and connectivity are statistically characterised.
Correlation between the effective diffusivity and the geometrical parameters of grain-boundary networks is demonstrated.

]]> 2018-10-11 09:40:52 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291625036 Crystal lattice defects tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291625848 2018-10-11 09:43:22 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291625848 Describe and explain 4 types of Point defect: tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291626124 2018-10-11 09:44:12 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291626124 Vacancy point defect tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291626390 In crystallography, a vacancy is a type of point defect in a crystal. Crystals inherently possess imperfections, sometimes referred to as crystalline defects. A defect in which an atom is missing from one of the lattice sites is known as a "vacancy" defect.]]> 2018-10-11 09:45:00 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291626390 Interstitial point defect tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291626831  Interstitials defects are a variety of crystallographic defects where atoms assume a normally unoccupied site in the crystal structure. Ininterstitial defects three or more atoms may share one lattice site, thereby increasing its total energy.]]> 2018-10-11 09:46:28 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291626831 Substitutional point defect (large and small) tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291627249 A substitutional impurity atom is an atom of a different type than the bulk atoms, which has replaced one of the bulk atoms in the lattice]]> 2018-10-11 09:48:03 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291627249 Describe what the following Dislocation defects are, how they are produced, and the likely material properties they are likely to cause tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291628218 2018-10-11 09:51:02 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291628218 Screw dislocations tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291628461 a dislocation in the lattice structure of a crystal in which the atoms are arranged in a helical pattern that is normal to the direction of the stress.]]> 2018-10-11 09:51:49 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291628461 Edge dislocation tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291628541 A dislocation which may be regarded as the result of inserting an extra plane of atoms, terminating along the line of the dislocation]]> 2018-10-11 09:52:05 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291628541 What is a planar defect? tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291628976 2018-10-11 09:53:33 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291628976 tarun_mudhar https://padlet.com/tarun_mudhar/grainstructure/wish/291629209 A Grain Boundary is a general planar defect that separates regions of different crystalline orientation (i.e. grains) within a poly crystalline solid. The atoms in the grain boundary will not be in perfect crystalline arrangement. Grain boundaries are usually the result of uneven growth when the solid is crystallising.]]> 2018-10-11 09:54:10 UTC https://padlet.com/tarun_mudhar/grainstructure/wish/291629209