Oman College of Management & Technology COURSE NAME: MATERIALS SCIENCE PROPOSED BY: DR.MOHAMED ALNEJEM SEMESTER: SECOND 2015/2016 CHAPTER (7): METALS

Transcription

1 Oman College of Management & Technology COURSE NAME: MATERIALS SCIENCE PROPOSED BY: DR.MOHAMED ALNEJEM SEMESTER: SECOND 2015/2016 CHAPTER (7): METALS 1

2 CHAPTER 7 : 2

3 METALS 3

4 Which of these things are made of metal? sleeping bag chest of drawers saucepan spanner toy car tap key medal box letter

5 WHAT IS A METAL? A metal is a solid material (an element, compound, or alloy) that is typically hard, opaque, shiny, and features good electrical and thermal conductivity. Metals are generally malleable, fusible and ductile. Currently, 91 out of the 118 total elements on the periodic table are classified as metals. Metals are broadly classified as (Ferrous and Non-Ferrous) FERROUS METAL NON- FERROUS METAL 5

6 What is Ferrous Metals? Outside of chemistry, ferrous is an adjective used to indicate the presence of iron. The word is derived from the Latin word ferrum ("iron"). A metal containing iron as a primary material. MAGNETIC gives little resistance to corrosion. 6

7 Examples Ferrous Metals? Iron Cast Iron Steel Stainless Steel Mild steel. Wrought Iron. High carbon steel. High speed steel. 7

8 WHAT IS NON FERROUS METALS? A non-ferrous metal is any metal, including alloys, that does not contain iron in appreciableamounts. They are generally more expensive than ferrous metals. not MAGNETIC gives more resistance to corrosion than ferrous metals. 8

9 Examples of NON FERROUS METALS? Aluminium. Copper. Zinc. Tin. Lead. Silver. Gold. Magnesium. 9

10 Comparison between ferrous and non ferrous metals: Point Ferrous metals Non-ferrous metals Contain Iron No iron Solidity Harder Hard Corrosion Little resistance More resistance Price Expensive More expensive Magnetic Magnetic Non magnetic Carbon High carbon Low or non carbon 10

11 PROPERTIES OF METAL PHYSICAL: HARDNESS BRITTLENESS MALLEABILITY DUCTILITY ELASTICITY TOUGHNESS FUSIBILITY CONDUCTIVITY DENSITY MECHANICAL: STRONG&HARD LUSTOER HEAT CONDUCTORS ELECTRIC CONDUCTORS DENSE SONOROUS SOUNF HIGH MELTING POINTS HIGH BOILING POINTS 11

12 Metal Shapes: Metal can be provided in various shapes and sizes. Some examples of these are shown below. Round Solid. Square Solid. Hexagonal Solid. Angle Iron Solid. Round Hollow. (Tube) Square Hollow. (Box Iron) Hexagonal Hollow. Angle Iron Hollow. 12

13 METHODS OF JOINING METALS SOLDERING. BRAZING. WELDING. RIVETS. 13

14 IRON 14

15 IRON Iron is a metal extracted mainly from the iron ore hematite. It oxidizes readily in air and water to form Fe2O3 and is rarely found as a free element. Iron is believed to be the sixth most abundant element in the universe Properties of Iron Luster Soft Malleable Ductile Strong Characteristics of Iron Easily magnetized Very reactive once exposed A good conductor of heat and electricity. 15

16 STEEL 16

17 STEEL: Alloys of iron and carbon Carbon content is no more than 2%. Alloy elements is composed of phosphorous, sulfur, oxygen, nitrogen, manganese, silicon, aluminum, copper, nickel, etc. Can be wrought, rolled, cast, and welded, but not extruded. 17

18 Properties of Steel: Luster Conductivity Malleable Ductile String Durable Characteristics of Steel: Its strength gives it advantage. The speed to assemble steel into its desired construction. 18

19 Types of STEEL Wrought Carbon Steels: Structural steel. Reinforcement of concrete. Sheet and strip. Corrugated steel. Steel Mesh and Wire Cloth. Steel Windows and Doors. Hardware 19

20 ALUMINUM 20

21 HISTORY OF ALUMINIUM Alum, from which the element aluminum takes its name was known from very early times. But a cheap method of extraction of Aluminum could not be discovered for a very long time. Aluminum was first isolated only in 1885 when Oersted obtained it by reducing Aluminum chloride with potassium. Then it was costlier than gold. 21

22 ADVANTAGES OF ALUMINIUM Lightweight. Excellent Corrosion Resistance. Strong at Low Temperatures. Easy to Work. Easy Surface Treatment. 22

23 DISADVANTAGES OF ALUMINIUM Thermal insulation was almost definitely insufficient: aluminum being a good thermal conductor. Poor water proofing due to the inadequately designed/executed joints between the roof aluminum sheets. General noise caused by rain or hail falling on aluminum roof and wall sheets. 23

24 Uses OF ALUMINUM: It is used for making door and window frames. It is also used in roofing, piping, etc, It is also used in electric wires, cables. 24

25 FORMS OF ALUMINUM In architectural work practically all fabricated forms of aluminum are used: - Rod. - Bar. - Extrusion. - Casting. - Sheet. - Strip. 25

26 EXTRACTION OF ALUMINIUM The production of 1Kg of aluminum requires around 2Kg of alumina. The production of 2Kg of alumina requires about 4Kg of bauxite. 26

27 27

28 Difference aluminum and PVC: Cost- Aluminum is much more costly than upvc Durability-although upvc has a long life it degrade over along time but aluminum does not corrode Cleaner profile-upvc has a thick channel profile while aluminum is thinner but the strength of aluminum Is good Flexibility-flexibility in upvc is less than compared to aluminum Colors- aluminum offer the vide range of colors as compared to upvc. 28

29 Point Aluminium PVC Cost More than - Profile Thinner channel Thick channel Strength Good strength - Durability - Long life Flexibility - Less than Colour Many colours Little colours 29

30 ZINC 30

31 Zinc: It is commonly used in building construction either as a base for paints or as protective coverings for metals. Zinc properties: Silvery-blue. Does not corrode easily. Ductile, Brittleness. Low strength. Good conductor of heat and electricity. Resists corrosion. 31

32 Zinc Uses: Uses in manufacture of other metals such as: Copper. Galvanized iron. Batteries. Used for preparing paints. 32

33 Examples for used ZINC in interior design: A metal containing little or no iron

34 LEAD 34

35 LEAD: It is widely used in building construction and has draw back of being poisonous. Properties of Lead: (1) It is bluish grey metal. (2) It is soft as it can be cut with a knife. (3) It is highly ductile. (4) It is a good conductor of heat and electricity. (5) It does not corrode. (6) Its specific gravity is Uses: (1) It is used as a base in paints. (2) Lead pipes and lead joints in sanitary fittings are extensively used. 35

36 BRASS 36

37 BRASS: Brass is an alloy of about % copper and zinc. Hardness of this alloy depends upon the amount of zinc present in it. Properties of Brass: (1) It is very strong. (2) It is ductile alloy. (3) It resists corrosion. Uses: It is widely used for making house hold utensils, water pumps and other machine parts. 37

38 BRONZE 38

39 BRONZE: Bronze is an alloy of 90 % copper and 10 % tin. It can be easily machined and cast. Properties of BRONZE: It resists corrosion. It takes a fine polish. hard-wearing. easily machined Uses: (1) It is used for manufacturing of house hold utensils. (2) Phosphorous bronze is used for making radio aerials and certain other instruments. 39

40 CHROMIUM 40

41 PROTECTING METALS CHROMIUM CHROMIUM is a steel-white metal which takes a brilliant polish and is harder than cobalt or nickel. Properties of CHROMIUM - Material is stainless steel. - Appearance does not change. - Stronger Sherardising than iron. is a method of galvanizing also called vapor galvanizing. A layer of zinc is applied to the metal target - The object price by is heating high. the object in an airtight container with zinc powder. The temperature that the container reaches - Durable does not material. exceed the melting point of zinc. Another method of sherardisation is to expose the intended objects to vapor - There from are molten sheets zinc or rods. using a reducing gas to prevent oxidation. - Used in (doors - windows - furniture - rails - Accessories...)

42 NICKEL 42

43 PROTECTING METALS NICKEL NICKEL is an inert silvery metal Properties of NICKEL Resistant to most acids. It resembles iron in strength and toughness and copper in its resistance to oxidation and corrosion. Takes a high polish. Can be hot and cold rolled forged. Nickel is as protective or decorative coating for other metals.

44 COPPER 44

45 COPPER: It is one of the most widely used non-ferrous metals. It is not widely used in Engineering due to its high cost. Properties of COPPER: (1) It is crystalline in structure, (2) Its color is reddish brown, (3) It is highly ductile, (4) It is excellent conductor of electricity, (5) When exposed to sun, its colour turns greenish, (6) It with stands corrosion, (7) It is soft and highly flexible, (8) It is light in weight, (9) Dents in copper can be hammered out without any damage to it. 45

46 TIN 46

47 TIN: It is one of the mostly used protective metals used in construction activities. Properties OF TIN Silvery-white metal. Non-magnetic. Fairly resistant to corrosion Non-combustible Lightweight Durable Soft Ductile Uses: It is used to give protective coatings to iron and steel sheets. 47