Metals Notes

Metals

Definition of metal:

An element or alloy where atomic structure readily loses electrons to form positively charged ions and which exhibits metallic bonding, Opacity, good light reflectance from a polished surface, and high electrical and thermal conductivity.

Alloy:

• Nonwhite metals in the periodic table are gold and copper.
• With the exception of pure gold foil commercially pure Ti and endodontic Ag paints, metals used for dental restoration partial denture framework, ortho-deontic wires, and endodontic instruments are alloys.
• A crystalline substance with metallic properties is composed of two or more chemical elements, at least one of which is a metal.

Alloys Types:

• Binary
• Ternary
• Quaternary

The simplest alloy is a solid solution in which atoms of two metals are located in the same crystal structure such as face center cubic body center cubic and hexagonal close pack.

• Alloy system: When two metals are completely soluble in each other.
• Eutectic alloys: Alloys in which the component metals have limited solid solubility.
• Peritectic alloy: Limited solid solubility of two metals.