Are a result of the solidification process and occur as a result of the misorientation of the grains as they are frozen into position. Thus, are regions with many irregularly placed atoms, dislocations, and voids.

Process where molten metal is extracted through the bottom of a water-cooled mold producing fine grained ingots with a minimum amount of segregation.

Process that utilizes electric currents to heat a crucible filled with solid metal (pure metal, master alloys ans recycled scrap) and eventually melt the metal within a vacuum chamber.

How does melting work in alloys?

Process is performed by lowering a consumable electrode into a molten flux, heat is generated by an electrical current, metal droplets fall through the liquid flux and are collected in a water-cooled mold.

Which of the following options is the first stage in solidification

Select materials used for expendable molds in casting

Liquid metal is poured into a metal mold and allowed to solidify. Mold materials include gray cast iron or hot work die steels. Suitable for the high-volume production of castings with fairly uniform wall thickness and limited undercuts or intricate internal coring

Is one of the fastest methods for net shape manufacturing of parts from nonferrous alloys. Generally limited to metals with low melting points. . It is ideal for the economical production of high-volume metal parts with moderately accurate dimensions.

Process used since the 60s to produce the hottest parts of the engine, blades and vanes. That has allowed the improvement since polycrystalline structures, to directionally solidifaction and in latter years to the singly crystal process in which a single crystal grows to form the entire blade.

Means a description of the arrangement of atoms, as seen at different levels of detail.

Type of atomic bonding that depends on sharing electrons

Type of atomic bonding that depends on free electrons and its highly non-directional

These are the most common crystal structures in metals except:

Type of point defect were an atom of a different element replaces an original atom of the crystal structure

Process of rapidly cooling metal parts from the austenitizing or solution-treating temperature, typically from within the range of 815 to 870 °C for hardening medium- and low-carbon steels to temperatures as high as 1232 °C for hardening specific grades of high-speed steels.

Process that involves uniform heating of a structure, or portion thereof, and holding at this temperature for a period of time, followed by uniform cooling. It can have various purposes and depends on the highest ttemperature reached.

Third and most times last step in steel hardening processes.

Basic elements of construction of heating furnaces, except:

Can be applied to introduce nitrogen-bearing ions to the surface of steel for improved nitriding. The furnace consists of a vacuum chamber in which a workload is suspended. A regulated voltage is applied between the chamber and workpiece in a vacuum.

Heated chambers' atmospheres in this type of furnace are evacuated to a very low level. In most operations, evacuation is to approximately 1 torr. Under these conditions the amount of original air remaining in the work chamber is approximately 0.1% or less.

Furnaces that consist of refractory lined covers equipped with heating devices in the form of direct firing burners, radiant type burners, and electric resistance heating units. Covers can be lifted off stationary bases by overhead cranes and relocated to spare bases.

Successful hardening usually means achieving the required microstructure, hardness, strength, or toughness while minimizing residual stress, distortion, and the posibility of cracking.

Hardened steel can be tempered to reduce hardness and to increase toughness.

All tempering operations are carried out at temperatures below the temperature A1 of austenite formation.