Material Science
Unit cell
a mixture of two or more metals
Screw dislocation
A deffect formed by distortion of the lattice as may be produced by a simple shear stress.
Alloy
A metallic substance that is composed of two or more elements.
Network Polymer
A polymer produced from multifunctional monomers having three or more active covalent bonds, resulting in the formation of three-dimensional molecules.
Bragg's law
A relationship that stipulate the condition for diffraction by a set of crystallographic planes.
Monomer
A stable molecule from which a polymer is synthesized.
Lattice
A structure consisting of strips of wood or metal crossed and fastened together with square or diamond-shaped spaces left between.
Noncrystalline
Amorphous, lacking three-dimensional order. Amorphous materials are either rubbers or glasses. normal stress The force divided by the area normal to the force.
Self-diffusion
Atomic migration in pure metals. Or when atoms change position in pure metals.
Single Crystal
For a crystalline solid, when the periodic and repeated arrangement of atoms is perfect or extends throughout the entirety of the specimen without interruption, the result is a ........
Miller Indices
Indices used to define crystallographic planes. The indices are specified as the lowest common denominator of the reciprocals of the intercepts made by a crystal face on the crystallographic axes.
Grain boundary
Interfacial defect, boundary that seperating two small grains or crystals having different crystallographic orientations in polycrystalline materials. or defect between adjacent crystals having different crystallographic orientations.
Edge dislocation
It is a linear defect that centers around the line that is defined along the end of the extra half-plane of an atom.
Cations
Metallic ions or ..... are positively charged
Crystalline
One in which the atoms are situated in a repeating or periodic array ( 3D array )over large atomic distances. Typical of : Metals, many ceramics, some polymers.
Isotropic
Substances in which measured properties are independent of the direction of measurement.
Isotropic material
Substances in which measured properties are independent of the direction of measurement. or when the mechanical properties of a material are independent of the direction in which measurement are taken.
Anisotopy
The directionality of properties is termed ...... and is associated with the variance of atomic or ionic spacing with crystallographic direction.
Crystal Structure
The manner in which atoms, ions, or molecules are spatially arranged.
Anions
The nonmetallic ions or ..... are negatively charged
Diffusion
The phenomenon of material transport by atomic motion.
Polymorphism
The phenomenon that some metals as well as non metals , may have more than one crystal structure
Linear polymers
are those in which the repeat units are joined together end to end in single chains. These long chains are flexible and may be thought of as a mass of a spaghetti.
Copolymer
composed of two or more mer units arranged as : random, graft, block, and alternating copolymer.
Weight-average molecular weight
considers weight percent of each range of molecular weights in determing the molecular weight of a polymer.
Fick's second law
equations representing the time-dependent change in diffusion. or the law governing the dependence of diffusion on time.
Lattice
it is the three-dimensional array of points coinciding with atom positions ( or sphere centers )
Diffraction
it occurs when a wave encounters a series of regurlarly spaced obstacles that 1) are capable of scattering the wave and 2) have spaciings that are comparable in magnitude to the wavelength. Futhermore, diffraction is a consequence of specific phase relationships established between two or more waves that have been scattered by obstacles.
Allotropy
polymorphism in elemental solids
Crystal structure
the manner in which atoms, ions, or molecules are spatially arranged.
Crystal system
the seven different possible combinations of the lattice parameters.
Lattice parameter
the six parameters of a unit cell. the three edge lengths (a, b,c ) and the three interaxial angles ( alpha, beta and gamma)
Schottky Defect
type of defect found in AX materials ( ceramics ) is a catio vacancy-anion vacancy pair. Or in ceramics,Schottky defect are missing a cation and an anion.
