Classification of Engineering Materials PDF

Chapter- 1 Classification of Engineering Materials 1. Introduction: “Material” means the matter from which things can be made or “object composed of matter”. Matter is composition of small physical particles called atoms. “Engineering” means the branch of science and te...

Chapter- 1 Classification of Engineering Materials 1. Introduction: “Material” means the matter from which things can be made or “object composed of matter”. Matter is composition of small physical particles called atoms. “Engineering” means the branch of science and technology concerned with the design, building, and use of engines, machines, and structures. “Engineering Materials” implied meaning shows that materials that are used in engineering applications. 2. Importance of studying “Engineering Materials” for Mechanical Engineers Mechanical engineers’ job in the industry is to design, manufacture, and maintain the engines, machines and products. Design is one of the jobs for mechanical engineers in which the shape of the product is developed by considering the applied forces. Manufacturing is the other job in which a part or product is made using different machines or processes according to the design. Maintenance is another job in which the aim is to keep the product or machines in good condition. Studying Engineering Materials helps mechanical engineers in the following ways: 1. Understand the properties of various materials. 2. Understand the testing methods of materials. 3. Selection of the best possible material for a specific application. 4. Ensure safety in Engineering products. 5. Ensure good quality in making products for customer satisfaction. 6. Optimize the costs in engineering products. 7. Continuous improvement of the product. 3. Classification of Engineering Materials: 1. Metals 2. Polymers 3. Ceramics 4. Composites 5. Semiconductors. 1. Metals : Metals are classified into two types 1. Pure Metals 2. Alloys Metals in clean form are called pure metals. Examples: Copper, Aluminum, Tin, Tungsten, Titanium, Zinc etc. Alloys are a mixture of two or more metals. Alloys are of two types : 1. Ferrous alloys: ferrous alloys means Iron-based alloys. In this Iron is the main alloying element. Examples: Steel, Stainless Steel, Cast Irons, etc. 2. Non-ferrous Alloys: These are not iron-based alloys. In these alloys, Iron is not the main alloying element. Examples: Copper-based and aluminum-based alloys. 1.1 General properties of Metals (Pure and Alloys) 1. They have high electrical and thermal conductivities. 2. They are ductile – easy to make into wires 3. They are malleable- easy to make into sheets. 4. They are formable- easy to make into any shape 5. They have high strength, high hardness, high toughness, and high stiffness values. Pure metals have comparatively low strength. But they are better conductors of electricity and heat compared to alloys. Pure metals are also more ductile and malleable compared to alloys. Alloys have improved properties compared to pure metals. They have more strength, hardness, toughness, and corrosion resistance than pure metals. Hence they are used more in machine parts. 1. Copper : Applications: Electrical Cables, Motor windings, Bottoms of cooking vessels Reasons: Good conductor of electricity and heat, ductile, malleable, and low cost, more available and easy to manufacture. Electric cable 1 Motor windings 2 Copper bottom vessel 3 1. Curtesy :https://en.wikipedia.org/wiki/Electrical_cable 2. Curtesy: https://www.google.com/search?q=motor+windings&tbm=isch&source=lnt&tbs=sur:fc&sa=X&ved=0ahUKEwjxwN- RjtziAhVDWBoKHQ6OBFkQpwUIHw&biw=1680&bih=939&dpr=1#imgrc=fzvN53IVkBhR0M: 3. Curtesy https://www.amazon.com/Revere-Copper-Bottom-1-Quart-Saucepan/dp/B00080QDKS 2. Aluminum : Aluminum in pure form is used for soft drink cans, window frames, food storage foils, and radiators. Advantages: lightweight, corrosion resistant, good electrical and thermal conductivity, malleable, low cost, can be recycled, more available easy for manufacturing. Can1 Window frame2 foil3 Radiator4 1. Curtesy : https://www.pixelsquid.com/png/aluminum-can 2. Curtesy : https://www.indiamart.com/proddetail/aluminium-sliding-window-frames-4065929612.html 3. Curtesy : https://www.123rf.com/photo_35418980_aluminum-foil-roll-on-the-white-background.html 4. Curtesy: https://www.indiamart.com/proddetail/aluminum-radiator-14710775662.html 3. Tin Applications: used for soldering, food cans, and plating on steel. Properties: good corrosion resistance, ductile, malleable, Low strength, soft, easy to cut. Soldering wire1 Food cans2 Juice maker3 1. Curtesy : https://ar.banggood.com/100g-0_8mm-6040-Tin-lead-Solder-Wire-Rosin-Core-Soldering-2-Flux-Reel-Tube-p-986166.html?cur_warehouse=CN 2. Curtesy : https://www.ecvv.com/product/3720735.html 3. Curtesy : https://www.amazon.com/Plating-Wheat-Juicer-Operated-Squeezer/dp/B07MFY2B9S 4. Titanium: Applications: Jet Engine Blades, Marine and Chemical plant parts. Properties: High strength, low density, retains properties at high temperatures, excellent corrosion resistance. Marine titanium Chemical plant3 Jet engine blades1 pumps2 1. Curtesy : https://www.theengineer.co.uk/rolls-royce-single-crystal-turbine-blade/ 2. Curtesy : http://www.bmgtitanium.com/titanium-pump-titanium-valve/ 3. Curtesy : https://www.toho-titanium.co.jp/en/products/ingot.html 5. Tungsten Applications: light bulb and electronic tube filaments. Properties: Tungsten has the highest melting point 3410o C of all the metals. It also has corrosion-resistant. filament1 6. Zinc Applications: toys, cogs, door handles. Properties: Zinc has very good corrosion resistance, hence it is used for coating on steel called galvanization. It has a low melting point. Zinc toys2 Zinc cogs 3 Handle 4 1. Curtesy : https://www.amazon.in/Glitz-Tungsten-Filament-Vintage-125x110mm/dp/B01EZU6IQ0 2. Curtesy:https://imall.com/product/1-52-Zinc-alloy-helicopter-model-toys-high-simulation-military-toy-metal-castings-mini-airplane-free-gift-people-doll/Hobbies-Diecasts- Vehicles/aliexpress.com/32967674719/144-17294739/en 3. Curtesy:https://thai.bestpriceupdate.com/%E0%B8%8B%E0%B8%B7%E0%B9%89%E0%B8%AD%E0%B8%97%E0%B8%B5%E0%B9%88%E0%B9%84%E0%B8% AB%E0%B8%99-100g-steampunk-zinc-alloy-gears-charm-european-pendant-fit-for-bracelets-necklace-diy-metal-jewelry-making-feng0022- %E0%B9%83%E0%B8%99%E0%B8%9B%E0%B8%A3%E0%B8%B0%E0%B9%80%E0%B8%97%E0%B8%A8%E0%B9%84%E0%B8%97%E0%B8%A2/ 4. Cutesy: https://www.indiamart.com/proddetail/zinc-door-handle-16100787212.html 7. Ferrous Alloys: Ferrous Alloys are the alloys of Iron. In these alloys, Iron is the major constituent. Carbon Steels: Alloy contains Iron and Carbon. 7.1. Mild Steels: If the carbon percentage is from 0.1 to 0.25 called Mild Steels. Applications: Joists in the Building, Car body work, Ships building, Screws, Nails ,Wires Car body work2 Ship building3 Joists in the Building1 Wires 6 Screws 4 Nails 5 1. Curtesy : https://www.needham-dbs.com/steel-joists-and-deck 2. Curtesy : https://www.worldautosteel.org/steel-basics/automotive-steel-definitions/ 3. Curtesy : https://deboerstaal.com/steel/ship-building-kit 4. Curtesy: https://www.amazon.com/Stainless-Steel-Screws-Inch-Hinges/dp/B07622VZ42 5. Curtesy:https://www.alibaba.com/showroom/steel-nails.html 6. Curtesy : https://www.homedepot.com/p/OOK-14-Gauge-x-100-ft-Galvanized-Steel-Wire-50142/100200924