Metal Microstructure Quiz

The smallest repeating unit in a crystalline structure.

The process of forming a new crystal from a liquid, typically initiated by atoms losing thermal energy and forming a unit cell.

The process of forming a new crystal from a liquid, initiated by impurities within the metal.

The boundaries between individual crystals in a metal, which are imperfections in the crystal structure.

Metals that are deformed by processes like hammering, rolling, or pressing.

The process of shaping metals by deformation, which can change the size and arrangement of grains.

A mixture of two or more metals, or metals and nonmetals, engineered to achieve specific desired properties.

The microscopic structure of a material, visible under a microscope, which can reveal information about its properties.

A structurally homogeneous region within a system that's physically distinct from other regions.

A mixture of two or more metallic elements (possibly with non-metallic elements), often produced by fusion at temperatures above their melting points.

A binary alloy contains two elements, and a ternary alloy contains three.

Grain structures are roughly equal in all dimensions.

Grain structures are elongated along a specific direction.

The process of a substance changing from a liquid to a solid state.

The process of forming a new crystal from a liquid, typically initiated by atoms losing thermal energy and forming a unit cell.

The process of forming a new crystal from a liquid, initiated by impurities within the metal.

Shows typical changes from liquid to solid substances, with nuclei of crystallization.

The boundaries between individual crystals in a metal, which are imperfections in the crystal structure.

A mixture of elements at the atomic level, where solute atoms replace solvent atoms at the lattice sites. This happens when atoms have similar valencies, crystal structures, and size differences within 15%.

A mixture of elements at the atomic level, where solute atoms fit into the spaces between solvent atoms. This occurs when the solute atom is significantly smaller than the solvent atom.

A compound formed when two or more metals combine in a specific, fixed ratio (stoichiometry).

A graphical representation of the phases present in an alloy at different temperatures and compositions. Usually, temperature is on the vertical axis and composition on the horizontal axis.

A type of phase diagram that shows the phases present in an alloy composed of two elements at different temperatures and compositions.

The ability of two elements to mix and form a homogeneous solid solution.

The maximum amount of solute that can dissolve in a solvent at a specific temperature.

A measure of the difference in electronegativity between two elements. It indicates the tendency for elements to form ionic bonds.

The tendency of elements to form ionic bonds. It increases with the electronegativity difference between the elements.

The tendency of metals to crystallize into specific structures (e.g., FCC, BCC).

A specific composition of an alloy where three phases (solid, solid, and liquid) coexist at a specific temperature. It signifies a point of equilibrium where the alloy can transition between these three phases.

A transformation where a solid solution (gamma) transforms into two different solid solutions (alpha and Fe₃C) at a specific temperature. This is a common reaction in iron-carbon alloys.

The process of a liquid turning into a solid. During solidification, the phase with the highest melting point crystallizes first, shaping the final structure of the metal.

The phenomenon where the composition of a metal is uneven, resulting in different concentrations of elements in different parts of the material. This occurs often during rapid cooling.

Tree-like structures that can form in metals during rapid cooling. They result from the non-uniform composition created by compositional segregation.

The temperature at which a molten metal begins to solidify upon cooling. Think of it as the starting point of crystallization.

The temperature at which the last liquid completely solidifies upon cooling. The final point of the transition.

The energy absorbed or released during a phase change between solid and liquid states. Think of it as the heat needed for melting or freezing.

The ability of one material to dissolve into another. Think of how sugar dissolves in water.

A cooling curve for a pure metal has a plateau at the melting point, meaning the temperature stays constant because the heat released during solidification balances the cooling effect. Think of a flat line.

The cooling curve of an alloy shows a temperature range for solidification because the mixture of metals solidifies progressively with different compositions. Think of a slope.

A phase diagram displays the equilibrium phases at various temperatures and compositions in a metal system, allowing you to predict the phases present for any composition at a given temperature. Think of a map.

This type of phase diagram illustrates the limited solubility of some materials, meaning they do not fully mix at an atomic level. Think of oil and water.

The size difference between copper and nickel atoms causes a range of compositions in the final solid, as copper and nickel solidify at different rates. Think of sorting marbles by size.

Phase diagrams are created by plotting cooling curves for various compositions. These curves show the temperature and composition at which phases change, defining the boundaries on the phase diagram.