Bachelor of TechnologyMechanical

Industrial Materials UOG

By: Jahangir Rana

Metals

•All metals belong to one of these two groups.

Ferrous Metals

Non-Ferrous Metals

Ferrous metalsFerrous metals are metals, which are mainly made of iron with small amounts of other metals or elements added in order to give the correct properties. Almost all ferrous metals are magnetic and can be picked up with a magnet. These metals rust or oxidise if not treated as they contain iron.

Non-Ferrous metals

Non-Ferrous metals are those metals, which do not contain iron. These metals are not magnetic and cannot be attracted by a magnet. Examples of these are aluminium, copper, lead, zinc and tin. These metals do not oxidise as they do not contain iron.

Ferrous Metals

Mild Steel Composition -0.15 to0.30% carbon Properties- Tough, high tensile strength, ductile. Because of low carbon content it can not be hardened and tempered. It must be case hardened.Uses- girders, Plates, nuts and bolts, general purpose.

High Speed Steel Composition- medium carbon, tungsten, chromium and vanadium. Properties - Can be hardened and tempered. Can be brittle. Retains hardness at high temperatures. Uses- Cutting tools for lathes.

Stainless Steel Composition- 18% chromium, and 8% nickel added. Properties - Corrosion resistant Uses- Kitchen draining boards. Pipes, cutlery, aircraft.

High Tensile Steel Composition- Low carbon steel, nickel, and chromium. Properties- Very strong and very tough. Uses- Gears, shafts, engine parts.

High Carbon SteelComposition- 0.70% to 1.40% carbon. Properties- The hardest of the carbon steels. Less ductile, tough and malleable. Uses- Chisels, hammers, drills, files, lathe tools, taps and dies

Medium Carbon SteelsComposition- 0.30% to 0.70% carbon.Properties- Stronger and harder than mild steels. Less ductile, tough and malleable. Uses- Metal ropes, wire, garden tools, springs.

Cast Iron Composition- Remelted pig iron with small amounts of scrap steel. Properties- Hard, brittle, strong, cheap, self-lubricating. White cast iron, grey cast iron, malleable cast iron.

Uses- Heavy crushing machinery. Car cylinder blocks, vices, machine tool parts, brake drums, machine handle and gear wheels, plumbing fitments

Non-Ferrous Metals

Aluminum Composition- Pure Metal Properties- Grayish-White, soft, malleable, conductive to heat and electricity, It is corrosion resistant. It can be welded but this is difficult. Needs special processes Uses- Aircraft, boats, window frames, saucepans, packaging and insulation, pistons and cranks

Aluminum alloys Composition- Aluminum +4% Copper+1%Manganese Properties- Ductile, Malleable, Work Hardens Uses- Aircraft and vehicle parts

Copper Composition- Pure metal Copper+1%Manganese Properties- Red, tough, ductile, High electrical conductor, corrosion resistant, Can work hard or cold. Needs frequent annealing Uses- Electrical wire, cables and conductors, water and central heating pipes and cylinders. Printed circuit boards, roofs

Brass Composition- 65% copper +35%zinc Properties- Very corrosive, yellow in colour, tarnishes very easily. Harder than copper. Good electrical conductor Uses- Castings, ornaments, valves, forgings

LeadComposition- Pure metal Properties- The heaviest common metal. Soft, malleable, bright and shiny when new but quickly oxidizes to a dull grey. Resistant to corrosion. Uses- Protection against X-Ray machines. Paints, roof coverings, flashings

Zinc Composition- Pure metal Properties- A layer of oxide protects it from corrosion, bluish-white, easily worked Uses- Makes brass. Coating for steel galvanized corrugated iron roofing, tanks, buckets, rust-proof paints

TinComposition- Pure metal Properties- White and soft, corrosion resistant Uses- Tinplate, making bronze

Gilding metal Composition- 85% copper+15% zinc Properties- Corrosion resistant, golden color, enamels well Uses- Beaten metalwork, jewelry

Pure metals and alloys

All metals fall into two categories.• Pure metals •Alloys.

A pure metal consists of a single element, which means that it is a metal only having one type of atom in it. The most commonly used pure metals are Aluminium, Copper, Iron, Lead, Zinc, Tin, Silver and Gold.

An Alloy is a mixture of two or more pure elements. Pure metals sometimes lack certain required properties. To create these properties a number of these pure metals are combined together.

Pure aluminium is rarely used because it is too soft. It is normally mixed with other metals, which produce aluminium alloys that are even stronger than mild steel, are resistant to corrosion but still retain the lightness of aluminium.