Geek weekly June 2016

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Abner Thompson
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1 1 1 Geek weekly June 2016 Blessed Ministry P.O. Box 2096 Madison, Al blessedministrieshsv@gmail.com

A metal is one of the basic elements in nature. Of the 92 or more known elements more than 70 are metal. Metal are good conductors of electricity and heat.

In the shop, all these materials are called metals even if some are actually alloys. There are two basic kinds of metals and alloys: ferrous and nonferrous metals.

2 A metal is one of the basic elements in nature. Of the 92 or more known elements more than 70 are metal. Metal are good conductors of electricity and heat. Physically they are generally hard, heavy, and tenacious. An alloy is a combination of two or more metals. For example, brass is a mixture of copper and zinc. In the shop, all these materials are called metals even if some are actually alloys. There are two basic kinds of metals and alloys: ferrous and nonferrous metals. The term ferrous comes from the Latin word ferum which means iron. Ferrous metals are those which contain iron or a considerable quantity of iron. Ferrous metals include the following:

3 1. Iron. A chemical element which is crystalline in nature. To metalworkers, pure iron is relatively a soft metal so it is combined with other metals. 2. Cast Iron. When iron is melt from its ores, it generally combines with a percentage of carbon from the coal or coke used for its heating. The result is cast iron. 3. Gray Cast Iron. Contains from 2.5 to 3.5 percent carbon. This kind of cast is most used in casting. 4. White Cast Iron. When the percentage of carbon is from 2.0 to 2.5, cast iron possesses extreme hardness but also becomes brittle. In metalworks where hardness is desired and brittleness can be tolerated, white cast iron is most suited. It is used extensively in the production of machine parts. 5. Malleable Cast Iron. Where ductility is desired, malleable cast iron is used rather than forging parts together. This type of cast iron may be bent or distorted under stress. It can load up to a certain limit without breaking. 6. Wrought Iron. Is almost pure iron containing a little slag (one to two percent). It is used in ornamental iron work and for many commercial purposes. It contains no carbon so it is almost rust proof. The presence of sulfur causes wrought iron to be brittle when hot. 7. Steel. Simple steel is an alloy of iron and carbon containing no other element. Commercial steels, however, are plain carbon steels containing manganese and small quantities of silicon, phosphorus, sulfur, and traces of other elements. Its carbon content is from a few hundredth of a percent to 1.4 percent. Plain carbon steel seldom contains more than 1.4 percent carbon. There are, however, steels which contain up to 2.0 percent. Aside from carbon, various other elements are added to give steel different properties suitable for different applications: Phosphorus. Improves hardness of steel and makes it more resistant to scratching and abrasions. Phosphorus, however, weakens steel against shocks and vibrations. Manganese. Improves the strength, hardness, and soundness of steel. Hardness and brittleness result if a considerable amount of this metal is added to steel. Nickel. Increases the strength and toughness of steel. This is added to steel to produce armor plates. Vanadium. Increases ductility of steel. It improves tensile strength, increases the electric limit of steel, and makes steel resistant to shocks. It renders steel nonfatigable. This type of steel is most suited for making spring, gears, and axles. Aluminum. Increases soundness of ingots and casting. Sulfur. Increases the brittleness of steel.

4 Molybdenum. Render steel hard even at high temperature. It produces the so-called high speed steel which makes steel suitable for crankshafts, propeller shafts, guns, rifle barrels, and broiler plates. The nonferrous metals are metals without iron but are as useful as iron in metalworks. Nonferrous metals include the following: 1. Aluminum. A very light metal which is gradually taking the place of iron in many application. This metal is malleable, ductile, and a good conductor of heat and electricity. It is a cheap substitute to the more expensive copper in many electrical installations. 2. Copper. Another very useful seddish-brown metal. It is malleable, ductile, and is next to silver in electrical and thermal conductivity. It is extensively employed in many electrical applications. When copper is alloyed with zinc, brass is produced. When alloyed with tin, bronze is produced. 3. Zinc. Used extensively in dry cells and batteries. It is used as sacrificial anodes attached to the hulls of sea-going vessels and in coating iron to produce galvanized iron.

5 4. Tin. Very malleable and can be rolled into very thin sheets. It is used in coating insides of pipes used for conveying drinking water. It is also plated insides cans used to conserve foodstuff due to its high resistance to tarnishing. 5. Lead. One of the densest metals. It is soft and can be cut with a knife. A two millimeter thick sheet may be bent or straightened with bare hands. It has been used extensively in plumbing but it being replaced by other metals. One popular application is the galvanized iron roofing, where lead washers are used. 6. Brass. An alloy of copper and zinc. The color may vary from red to yellowish-white depending on the percentage of zinc. It is used in producing many articles such as Muslim brass works, bells, commutators, slide contacts, and many others. 7. Bronze. An alloy of copper and tin. It has a better appearance and greater strength than bass. It is used in bushings and in many other applications.

Muntz metal. A special form of bronze with 60 percent copper and 40 percent tin. It is used in application where hard brass is required.

6 8. Babbit metal. An alloy of tin, antimony, and copper. It is a good electrical and heat conductor. 9. Monel metal. An alloy of copper, nickel, and a small percentage of iron. It is used extensively in the manufacture of ship s propeller. 10. Muntz metal. A special form of bronze with 60 percent copper and 40 percent tin. It is used in application where hard brass is required. Different metals have distinct characteristics and properties which make them suitable for specific purposes. The following are the usual properties of different metals:

7 Hardness. Allows a metal to resist penetration. The harder the metal the less likely it is to change in shape. Hardness can be increased by hardening or heat treating. Brittleness. Makes a metal break easily. Certain kinds of cast iron are brittle and break when dropped. Hardness and brittleness are closely related since hard metals are more brittle than soft metals. Malleability. Allows a metal to be hammered or rolled out into thin sheets without breaking or cracking. Ductility. Allows a metal to be drawn out into thin wires without breaking. Copper is very ductile and therefore makes very good wire. Elasticity. Allows metals to return to its original shape after bending. Steel used in making springs is a good example. Fusibility. Allows metals to become liquid easily and join with other metals to form an alloy. Machinability. Involves several properties. Some of these are the rate at which the material can be removed in machining, the chip, the amount of tool wear, and the kind of surface finish. 5 Metals You Probably Never Heard about Whether it is your laptop, your mobile phone or the very roof you re under, everything comprises of metals and their alloys. Metals have been a part of our lives ever since the Stone Age when man crafter spears and arrows out of metals to hunt and poach. We have come a long way since then by using the same metals to satiate all our industrial and personal requirements. However, with the 91 metals present of the Periodic Table, you can surely miss out no more than a couple and not know what they re used for. So here are 5 metals that you ve probably ever even heard of until now.

8 1. Gallium This shiny metal is a soft in nature and its melting point is just slightly above the normal room temperature. The chemical symbol of Gallium is Ga and it has an atomic number of 31. Gallium the byproduct formed from Aluminum and Zinc and is widely used in building the computer chips in electronics. The latest use of Gallium is as doping semiconductors in blue-light LEDs. 2. Indium This metal is produced from zinc ore, iron ore, copper ore as well as lead ores yet is rare in occurrence. It is white in color with a shiny polish and extremely malleable in nature. Indium has been used worldwide for non corrosive mirrors, semiconductors and in flat panels for electrical connectivity. 3. Rhenium This rare earth metal has the third highest melting point and has the highest density. This byproduct of Molybdenum is revived from mining of copper. This major of Rhenium is in high temperature turbine engines (since it does not melt easily), filaments and thermocouples. 4. Palladium This foggy white metal is valued on the basis of its rare natural occurrence, stability under heat, hydrogen absorption quality and high malleability. Catalytic converters in automobiles are reliant on palladium for reducing emissions as it is highly hydrogen absorbent. It is famously used to create white gold for jewelry and is great for electronic plating as well. 5. Iridium This metal is one of the most extreme members of the platinum group of metals and has a very high melting point. Iridium has a high density and is hands down the most naturally corrosive resistant metal. It is processed from platinum ore and a nickel byproduct. Iridium has high significance in the field of medicine, automobiles as well as electronics. Due to its corrosion resistant properties, it is popularly used in watch making, pens as well as compasses.

9 5 Most Expensive Metals in the World There are many different types of metals in the world. In recent years, a lot of investors have started investing in precious metals. Thus, it s important to have a better understanding of metal prices to make sure you make informed choices. In this post, we ve discussed the 5 most expensive metals in the world. Platinum This one is perhaps the rarest of precious metals. In fact, it s about 30 times rarer than gold. This expensive metal is used for making spark plug tips, jewelry and numerous other applications, such as weaponry, aeronautics and dentistry. Platinum is predominantly found in Russia, Canada and South Africa. Gold This is one of the most common and recognized precious metals in the world. It s considered the most ductile and malleable of all precious and expensive metals. This makes it suitable for commercial applications and jewelry. This metal is also used as a protective coating in many different artificial satellites. Some major gold mines are found in the United States, South Africa, China and Australia. Rhodium Rhodium is often used for its reflective properties in mirrors and searchlights. It s also used in the automotive industry for a wide range of catalytic applications. It s a member of the platinum family of metals. Rhodium is silvery, hard and durable with high reflectance. It s worth mentioning that white gold is commonly plated with a very thin layer of rhodium to improve the metal s appearance. Silver is also plated with rhodium for making it resistant to tarnish. More than 60% rhodium is mined in Russia and South Africa. Palladium

10 Palladium was first discovered in the early 1800 s. Since then, it has been considered equally rare as platinum. The primary uses of palladium include computer components, catalytic converters, mobile phones and more. In jewelry, palladium is used in the creation of white gold alloys. More than 50% of palladium is produced in Russia. The next large suppliers of palladium include the United States, Canada and South Africa. Rhenium Last but not the least, rhenium is another one of the most expensive metals in the world. In fact, it s the most recent naturally occurring stable element to be discovered. It was first discovered in This metal has a very high melting point and density. Due to this, it s the perfect choice for construction of jet engines, and filaments in electrical contact materials. The largest rhenium reserves in the world come from Kazakhstan, the United States and China. Rhenium is quickly becoming a popular metal for investment purposes.

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

Oman College of Management & Technology COURSE NAME: MATERIALS SCIENCE PROPOSED BY: DR.MOHAMED ALNEJEM SEMESTER: SECOND 2015/2016 CHAPTER (7): METALS 1 CHAPTER 7 : 2 METALS 3 Which of these things are