METALS

Metal

Chemical element that is malleable and ductile usually solid, has properties of luster, good conductor of heat and electricity

Ferrous metal

• contain iron

• magnetic

• durable and strong

• relatively inexpensive

• more likely to rust

• silver

Nonferrous metals

• does not contain iron

• non-magnetic

• lighter and malleable

• more expensive

• high corrosion resistance

• colorful

Iron, cast iron, malleable iron, wrought iron, steel, stainless steel

Examples of ferrous metals (6)

Iron

- Soft, easily worked, oxidizes rapidly, susceptible to acid.

Steel

Iron with carbon, strongest metal, for structural purposes

Stainless steel

- An alloy for max. corrosion resistance; for flashing, handrails, hardware, connections, and equipment.

Cast iron

- Brittle, corrosion-resistant, high compressive strength; for

gratings, stairs, etc.

Wrought iron

- Soft, corrosion- and fatigue resistant, machinable; for railings, grilles, screws, and ornamental items.

Aluminum, Lead, Zinc, Chromium and Nickel, Monel, Copper, Bronze, Brass

examples of non ferrous metals (8)

Aluminum

-Soft,ductile,highcorrosionresistance,lowstrength

Lead

-Dense,workable,toxic,corrosionresistant.Improvedwithalloysfor hardness and strength. Used as waterproofing, sound isolation, and radiation shielding

Zinc

-Corrosion-resistant,brittle,lowstrength.Usedin“galvanizing"ofother metals for corrosion resistance for roofing, flashing, hardware, connections, etc.

Chromium and nickel

-Used as alloy for corrosion-resistantbright“plating.”

Monel

-Highcorrosionresistance;forfastenersandanchors.

Copper

-Resistanttocorrosion,impact,andfatigue.Ductile;forwiring, roofing, flashing, and piping.

Bronze

-Analloyfor“plating.”

Brass

-Copperwithzinc;forhardware,handrails,grilles,etc.

Nickel

Added to improver hardenability and increases impact strength at low temperature

Sulfur

increases machinability

Manganese

increases strength and hardness

Carbon

– the principal hardening agent in steel

Molybdenum

– prevents brittleness

Vanadium

– gives fine grain structure and improves fatigue values

Silicon

– improves strength, it is deoxidizer

Phosphorous

– improves machinability of high-sulfur steels and imparts some resistance to corrosion

ductile

ability to absorb energy without fracturing

modulus of elasticity

(measure of its resistance to strain)

Ductile, linear (elastic) and/or nonlinear (plastic) behavior, strength, modulus of elasticity

Structural behavior of steel

fluorocarbons

High performance exterior coating, has excellent abrasion and impact resistance, stain and weather resistance, high gloss retention

Siliconized polymer

Good resistance to color change and weathering

Vitreous coating

Hardest, most durable but brittle, to act against the effects of deformation – cracking and spalling

Galvanizing

Zinc coating to avoid rust

Anodizing

Coating common for aluminum

Powder coating

Durable, uniform color finish coating

Iron

Metals containing substantially no carbon (several hundredths of 1%) are called

Steel

the world's foremost construction material, is an iron alloy that contains between 0.2% and 2% carbon by weight and sometimes small amounts of other elements, including manganese. In addition to buildings, it is used in the manufacture of appliances, cars, and airplanes.

Alloy steels

contain other metals such as aluminum, copper, or nickel. They may be used in auto parts, pipelines, and motors.

Stainlesssteels

always contain chromium and maybe also nickel or molybdenum. They are shiny and generally resistant to corrosion. Because are easily sterilized, they are often used in medical equipment and instruments and food production equipment.

Tool steels

are alloyed with hard metals such as vanadium, cobalt, molybdenum, and tungsten. As their name suggests, they are often used to make tools, including hammers

Hot rolled steel

has been roll-pressed at high temperatures (over 1,700F), which is above the re-crystallization temperature for most steels. This makes the steel easier to form, and results in products that are easier to work with

Cold rolled steel

is essentially has gone through more processing. manufacturers generally take cooled-down hot rolled steel and roll it more to get more exact dimensions and better surface qualities.

Hot rolled

• Scaled surfaces, the remnants of cooling from extreme temperatures.

• Slightly rounded edges and corners for bar and plate products (due to shrinkage and less precise finishing).

• Slight distortions, where cooling may leave slightly trapezoidal forms rather than perfectly squared angles.

Cold rolled

• More finished surfaces with closer tolerances.

• Smooth surfaces that are often oily to the touch.

• Bars are true and square, and often have well-defined edges and corners.

• Tubes have better concentric uniformity and straightness.

Non-ferrous metals

have industrial applications because of their case of fabrication (like rolling, forging, casting, welding, and machining), electrical and thermal conductivity, resistance to corrosion, light-weight, etc.

bauxite ore.

Aluminum is mainly obtained from

Aluminum

1. It is silvery-white metal and shows brilliant luster when fresh. 2. It is an excellent conductor of heat and electricity.

3. It is light in weight with a specific gravity of about 2.7.

4. It is a good reflector of light.

5. It is non-magnetic and has high resistance to corrosion.

6. It is soft, tough, malleable, and ductile.

7. It is very ductile and can be transformed into any shape by rolling, stamping, extruding, forging, drawing, and spinning.

8. Its melting temperature is about 658°C.

9. It has high tensile strength.

10. It can also be cast into any shape by any method of casting, i.e., die casting, chill casting, and sand casting.

11. It is resistant to organic acids, salt solutions, etc.

Aluminum

1. It is used in the manufacturing of equipment for chemical and food industries, cooking utensils, cookers, steam-jacketed kettles, etc.

2. Due to its lightweight and high tensile strength, it is used in structural work of airplanes, ships, trains, buses, trucks, etc. And also used for roofing, sheathing, window frames, foils, posts, etc.

3. It is used for manufacturing of electric cables.

4. Used for manufacturing of reflectors and mirrors. 5. Aluminum powder is used for preparing paints.

6. It is used in iron and steel making as a de-oxidizer.

Copper

1. It is soft, strong, tough, malleable, and ductile.

2. It is very malleable and ductile so that it can be converted into any desired shape.

3. It has excellent joining properties, i.e., it can be joined by almost all the common methods: welding, soldering, brazing, and riveting.

4. It becomes brittle just before melting.

5. It can be forged, soldered, rolled and drawn into wires.

6. It has good resistance to corrosion.

7. It is a good conductor of both heat and electricity next to silver.

8. It forms excellent alloys.

9. It is reddish-brown in color.

10. Its specific gravity is 8.93.

11. It has a melting point of 1083°C.

Brass and bronze

Copper alloys

Lead

1. It has bluish Grey color.

2. It has typically brilliant luster.

3. It has a high density – 11.35 g/cm3.

4. It has a low melting point of 327 centigrade. 5. It has a high boiling point of 1744 centigrade. 6. It is very good at resisting corrosion.

Lead

doesn’t form many alloys. Its alloying capacity is limited because of its low melting point.

zinc

chief ore mineral of zinc is sulfide called sphalerite.

• Smithsonite, Zincite (ZnO) and Calamine (ZnCO3) are other common zinc minerals.

Zinc Properties

1. It is bluish-white in color and has bright luster.

• 2. It resists corrosion.

• 3. It is brittle at normal temperature.

• 4. It becomes malleable and ductile when heated to a temperature of 100 to 150°C. Hence, at this temperature, it can be rolled into sheets and drawn into wires.

• 5. It has a density of 7.14 g/ml.

• 6. It has a melting point of 419 centigrade and boiling

point of 907 centigrade.

• 7. It has a tensile strength of 700-1400 kg/cm2.

• 8. Commercial zinc (spelter) is easily attacked by acids.

• 9. surface is covered by a dull basic zinc carbonate in moist air.

Nickel

was first discovered in 1750. It is manufactured from its sulfide ore named pentlandite

Nickel

The ore is first concentrated by froth flotation process and then roasted and smelted like other non- ferrous metals

Nickel

1. It is the strongest metal in all the non-ferrous metals, having tensile strength ranges from 4200-8400 kg/cm2.

2. It is highly resistant to many types of corrosion. Thus it can withstand in water, moisture, atmospheric gases, etc

3. Its modulus of elasticity, thermal and electrical conductivity is the same as steel

4. It is highly malleable and ductile. 5. Its density is 8.9 g/cm3.

6. It has a melting point of 1455 centigrade.

Magnesium

forms the lightest materials used in structural engineering. It has a set of properties that make it suitable as an engineering material.

Magnesium

It is very light with a specific gravity of 1.74.

2. It has a melting point of 650 centigrade, which is similar to that of aluminum.

3. It has poor corrosion resistance.

4. It has quite a high thermal conductivity and a high coefficient of thermal expansion.

5. It forms very useful alloys with some metals like aluminum, thorium, zinc, zirconium, and tin, etc.