Lecture on Metallic Materials and Alloys

These flashcards cover key vocabulary related to metallic materials and alloys, including definitions and essential concepts from the lecture.

Metallic Mat

Crystalline substances that tend to ionize positively in solutions.

Space Lattice

A regular three-dimensional network of a crystalline material.

Alloy

A combination of two or more metallic coats melted together at their fusion temperature to produce a solid or a compound.

Metalloid

A substance that has properties of metals but does not ionize positively in solution.

Malleability

The ability of a metal to be shaped or bent without breaking.

Ductility

The ability of a metal to be stretched into wires.

Solid Solution

A homogeneous mixture of two or more substances which forms a single solid phase.

Intermetallic Compound

A compound consisting of two or more metals that exhibits brittle behavior.

Coring

A process where a molten alloy solidifies from a primary dendrite.

Deformation

The process of altering the shape or structure of metallic materials.

Grain Growth

The increase in size of crystal grains in metals due to excessive heating.

Annealing

A heat treatment process to relieve internal stresses and improve ductility.

Hydrometallurgical Method

A method of extracting metals that involves the use of aqueous solutions.

Thermal Method

Extraction method where ores are heated to convert them into a more usable form.

Creep

The slow, time-dependent deformation of materials under a constant load.

Nucleating Agent

Substances that facilitate the formation of new crystal phases during solidification.

Phase Diagram

A graphical representation of the physical states of a material at different temperatures and compositions.

Noble Metal

A metal that is resistant to corrosion and oxidation in moist air.

Scavenger

A substance introduced to a molten material to remove impurities.

Dental Amalgam

An alloy made from the mixture of mercury and powdered metals used for dental fillings.

Solution hardening

This is the strenghing of metal by adding different atoms that interfere with dislocation motion.

Grain boundary

This is the interface between two crystals of different orientations within a polycrystalline metal or alloy

What are methods of forming and shaping

Casting, cold working, metallurgical method, electro forming method

What are the methods used in extracting metals from ores

Thermal methods

Hydro metallurgical method

Thermal electrolytic methods

What is a scavenger

It is a substance introduced into a material to Improve flow property and remove impurities e.g cobalt, stainless steel, titanium,gold etc

What is a refractory material

This is a substance that is resistant to high temperature, thermal shock and chemical corrosion. They are designed to withstand heat and maintain structural integrity in harsh conditions e g fireclay, silicone carbide,graphite , alumina, and magnesite.

What is a phase

This is defined as a body of matter that is physically distinct and mechanical distinguishable.

What is another name for 18/8 stainless steel

Type 304 stainless steel

What is weld decay

This is a form of corrosion that occurs in stainless steel at heat affected zone of a weld caused by the formation of chromium carbides.

How to avoid weld decay

Use low carbon stainless Steels

Use stabilized alloys

Use proper welding technique

Use a higher welding speed

Use of anti-scaling flux

Welding in a controlled atmosphere

What plays the role of scavenger in cobalt chromium alloy

The combination of mangase silicone and iron

What is an emulsifier

This is a substance that helps stabilize an emulsion ( a mixture of two Immiscible liquids that normally do not combine

What is an intermetallic compound this refers to a phase where two or more metals combine in a fixed stoichiometric ratio to form a distinct crystalline structure

this refers to a phase where two or more metals combine in a fixed stoichiometric ratio to form a distinct crystalline structure e.g titanium aluminide , nickel aluminide and copper zinc.