Giving a proper or correct answer to the question of ‘What is Metal?’ is a very difficult task. Because this changes according to the professions of different individuals who are searching for the answer.
If you are asking these questions from an engineering point, we must provide a proper answer which takes up ‘metals’ from an engineering viewpoint.
If someone is a chemist, we need to give a proper answer to this ‘What is metal?’ question in terms of chemistry. So we will try to answer this question from different kinds of viewpoints and the most general viewpoints.
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What is Metal?
To give a general answer to this question, we can say; Metals are a material class that exhibits very high thermal and electrical conductivities, very high formability with different production processes, very high tendency to oxidation. They generally have a very apparent glossy appearance compared with other material classes.
If we take a look from a chemistry viewpoint, metals are the element class that has a special ‘electron sea’ with their last layer of electrons. These electrons can roam freely throughout the different atom clusters. This property of metals gives them their high malleability and formability features. Also, this special ‘electron sea’ feature gives high electrical and thermal conductivity features to metals.
What are the Important Properties of Metals?
Metals are very important for human civilization. If you take a look around yourself, you can see lots of usage areas and products of metals. In most daily applications, you can see metals that have the most important role in that.
As we stated above, one of the most important properties of metals is that they have very high capabilities. Because of these properties, they can get various kinds of shapes with different manufacturing and shaping methods. Because of this special property, lots of kinds of components and applications of systems such as automobiles, aircraft, and household appliances are metals.
It is another important and often unaware feature that generally all the metals are solid at room temperatures except the mercury. This property of metals gives the advantage to shape and use in lots of daily applications of human civilization.
As we stated above again, metals conduct electricity and heat very well compared with other materials. Because of it, people use them generally in thermal applications such as automobile engines, household heaters, etc. And also because of their very high electrical conductivities, they use electric transmission lines.
The biggest disadvantage of metals is that they have high densities compared with other material and element groups. We use metals widely in different civilization systems but also make them very heavy because of this feature.
Metals are very strong. Because of this feature of metals, we use them generally in structural applications such as automotive car bodies, bridges, buildings, etc.
The chemical feature of metals which we do not compound them with other elements. Metals are generally alloyed with other elements and materials to obtain much superior material characteristics.
What are the Types of Metals?
According to the periodic table, there are 93 metal types. The scope of the types of metals is very wide for this general introductory article. We would like to give information about the general metal types which they use widely in daily human civilization.
The first use of iron is estimated to start from 4000 B.C. by Egyptians and Sumerians. They made spear tips and other hand tools from metals. History is a very exciting topic but it will be also better to get down to more technical details about iron…
But ‘Iron’ is a very confusing concept for most people. But it states a single element in a periodic table. According to the periodic table, iron is a kind of metal which have an atomic number of 26 and has the symbol ‘Fe’. If we give the other numeric features of the iron;
- The melting temperature of the iron is 1538°C. The boiling temperature of the iron is 2861°C.
- The heat conductivity of the iron is 80,4 W/(m·K).
- The density of the iron is 7,86 g/cm³.
There is a very big reason that we brought the iron to the top of our list. Iron and iron-based alloys are responsible for 95% of the total metals that we use in modern society. Because of its high mechanical strength, high alloying capability, high electrical and thermal conductivity, and cheapness, iron is one of the most used metals by far in human society.
There are different types of usage forms of iron which you will aware of;
Steel is a special form of iron that we obtain by alloying iron with a carbon content of up to 2.11%. We enhance the toughness of the iron with the carbon alloy. Also, we obtain very good corrosion resistance with carbon addition.
With the changing percentage of carbon content in iron, the properties and commercial names of the materials change. Pig iron is a special iron-carbon alloy that contains around 4-5% of carbon.
With the increasing amount of carbon, the mechanical and commercial properties of iron change. Cast iron is a type of iron-carbon alloy that includes more than 2.11% of carbon content. Cast irons have very good mechanical strength and sound and shock absorption characteristics which we use in structural elements of moving machinery.
Aluminum is another important metal that we use widely in modern society. There are also different kinds of applications and alloys of aluminum. If we need to give some numerical details about aluminum;
- The atomic number of aluminum in the periodic table is 13 and aluminum has the symbol of ‘Al’ which is very easy to remember from its name…
- The density of the aluminum element is 2,70 g/cm³ which is very low if we compare with other metal types.
- The melting temperature of the aluminum is 660,32 °C and the boiling temperature is 2519 °C.
- The thermal conductivity of the aluminum is 237 W/(m·K).
The most important characteristic of aluminum is, that it has a very low density compared with other metals and electrical and thermal conductivity is very high. Because of this feature, they use aluminum and aluminum alloys generally in HVAC industries and it is much cheaper if we compare it with other copper.
With its bare features, they do not use aluminum generally. They are alloying aluminum with different kinds of elements to obtain preferable features in most applications.
They use the oxides of aluminum also in various industries and applications. These aluminum oxides have generally very high thermal strength and very good mechanical characteristics which we use in refractory applications such as molds of castings.
Copper is a very important metal for human society(You don’t say?). Because of its unique properties, we use copper and its alloys in very specific applications. But first of all, let’s give some memorization information;
- The atomic number of copper is 29 and its symbol in the periodic table is ‘Cu’ which is very hard to remember.
- The density of copper is 8,96 g/cm³ which is above the average around metals.
- The melting point of copper is 1084,62 °C which is also average.
- The boiling point of the copper is 2562 °C which can be very important information if you think to boil a container of copper.
- The thermal conductivity of copper is nearly 401 W/(m·K) and the electrical resistance of copper is 16,78 nΩ·m which is very low if we compare with other metals.
Because of its feature that we can find in nature in pure form, copper has been used from a very early age around 9000 B.C. by Egyptians.
Because of its distinct properties such as very low resistance to electrical and thermal conduction, copper and we use its alloys widely in electrical and electronic applications. But the biggest disadvantage of copper is that it is slightly expensive to use in commercial applications. Aluminum can be a good alternative generally because of this financial situation.
You can remember doctors who appear on TVs that consume zinc for a healthy life. Because of this, people may think, that zinc is an important supplementary FOOD. But it is just a metal from the periodic table. And it is 4th metal that is used by human civilization, after iron, aluminum, and copper.
Again, we can give some periodic table pieces of information about zinc;
- The atomic number of zinc is 30 in the periodic table and its symbol is ‘Zn’ which is also very basic to remember from its name.
- The density of the zinc is 7,14 g/cm³ which has an average value according to other metals and is high if we compare with other materials.
- The melting point of the zinc is 419,53 °C which is somewhat low if we compare with other metals.
- 907 °C is the boiling temperature of the zinc which is also very low.
- The thermal conductivity of zinc is 116 W/(m·K) and the electrical resistivity of the zinc is 59,0 nΩ·m.
Zinc is a very important alloying element in the metal industry that we generally use in different applications for different purposes. For example, they use zinc as the primary coating metal on steel parts which we call as galvanizing. This method increases the resistance of the corrosion of metals.
Another application is that they use zinc widely battery body. The technical side of the galvanizing process depends on this application.
Like zinc, magnesium is also a very important supplement that doctors suggested consuming for health. But also magnesium is another metal in the periodic table which has distinct properties like zinc. If we give general information about magnesium;
- The atomic number of magnesium is 12 and its symbol is ‘Mg’ which is very easy to remember from its name.
- The density of the magnesium is 1.738 g/cm³ which is very low if we compare it with other metals and maybe the lowest one! Because of this property, magnesium finds very important applications in human society.
- The melting temperature of the magnesium is 650 °C which averages around metals.
- The boiling point of the magnesium is 1090 °C which is average around metals again.
- The electrical resistivity of the magnesium is 43.9 nΩ·m which makes it the preferred material in electrical conduction applications. And the thermal conductivity of the magnesium is 156 W/(m·K).
In aerospace and defense industries, magnesium use its alloys mainly because of its lightweight feature. But also its mechanical strength is very high according to its lightweight nature. So, they prefer magnesium alloys in structural applications in aerospace and defense applications and systems.
The powder form of magnesium is highly flammable and it produces a very high intensity of light when we ignite it. Because of this feature, we use magnesium generally in pyrotechnics and flashes of cameras.
We know this metal in coating and alloying applications. Because of its unique features, they use nickel in these applications. There are different historical pieces of information about the use of nickel in history such as it is used by Chinese people around 1400-1600 B.C.
If we delve into some technical details and nickel;
- The atomic number of the nickel is 28 and its symbol in the periodic table is ‘Ni’.
- The density of the nickel is 8908 g/cm³ which is slightly high if we compare it with other metals.
- The melting temperature of the nickel is 1455 °C which is quite high if we compare it to other metals that we covered.
- The thermal conduction of the nickel is 90,9 W/(m·K) and its electrical resistivity of it is 69,3 nΩ·m.
We use nickel primarily as an alloying element in the metal industry which they alloy with different kinds of metals; Aluminum, Iron, etc. A special application of nickel that they use to give green color to the glass.
Precious. Everybody wants to store some gold for financial situations… If you have enough amount of gold in your bank account, your situation is good actually. In every bit of history, gold was precious metal… But one may wonder about the chemical and physical features and properties of gold, even if it is not used because of them.
- The atomic number of gold is 79 and its symbol is ‘Au’ in the periodic table.
- The density of pure gold is 19,3 g/cm³ which makes it very very heavy.
- The melting temperature of the gold is 1064,18 °C and the boiling temperature of the gold is 2856 °C.
- The thermal conductivity of the gold is 318 W/(m·K) and the electrical resistivity is 22,14 nΩ·m which is very low compared with other metals.
Because of its very low electrical resistivity, gold is generally used in very low amounts in electrical circuits. But in general, gold is an investment tool because of its price.
Silver is another precious metal that is generally used as an investment tool. But also, daily and engineering applications of silver are much higher than gold. And it is not valuable like gold. Because of its low mechanical strength, it is generally used as alloying metal with other metals. Some technical information about silver;
- The atomic number of silver is 47 and its symbol is ‘Ag’ in the periodic table.
- The density of pure silver is 10,49 g/cm³ which makes it very very heavy compared with other metals.
- The melting temperature of the silver is 961,78 °C and the boiling temperature of the silver is 2162 °C.
- The thermal conductivity of the silver is 318 W/(m·K) and the electrical resistivity is 15,87 nΩ·m which is very low compared with other metals.
Also because of its very low electrical resistivity, silver is generally used in electrical applications.
What are the Current Metal Prices?
In the stock market, metals have a very important place which is heavily traded between producers and industries. Because of the prices of raw metals in the world, the general prices of the products which are produced from metals can be affected.
Which Factors Affecting the Metal Prices?
Different factors are affecting the metal prices in the world;
- Logistics: Transforming the metal from the production sites to manufacturing sites is a separate business. The total worth of logistics to carry metal from production place to manufacturing sites affects the general metal prices.
- Production Rates: Production rates of metals can decrease or increase because of various reasons. But production rates of metals are a primary factor that affects the general prices of raw metals in the world.
- International Politics: Some countries produce metals in high amounts some countries low. The production can be affected by the internal economical politics of the country where metal is produced. And the logistics can be affected by international politics. If there is a war or another economical war between countries, the transmission of raw metals can be affected and prices are affected.
- Supply and Demand: Actually, it is a very basic rule of economics. If demand is low, prices get low. If demand is high, prices are high. But the balance between supply and demand is very important in metal prices. If metal demand is high and supply is low, metal prices increase, otherwise, metal prices decrease.
General Trend of Metal Prices in the World
If you are looking from an investor viewpoint to different metals, we can give some quick information about general metal prices in the world.
Because of its value, the prices of gold get higher and higher year after year. According to its 20 years of trend, gold can be a very good investment tool.
Because of its lower price compared with gold, silver is not generally used as an investment tool. But if you have a business that has a great business with silver, take care about the increasing prices over the years.
Iron Ore Prices
Iron ore prices are an important parameter in general industrial production around the world. If you take a look at the decade-long chart below, you can comment that there is no ongoing increment over the years in iron prices. There are some kinds of peaks and bottoms in that chart but if you look at the general situation, there is no increment over the years.
Because of its rarity in nature and increased use in the high-technology, you can see the rapid increment of the prices around 2005s. Also in general, the prices of copper go up over the years because of the demand. Increment in the prices of copper is a very important example of a supply and demand balance.
Around the middle of the 2000s, the demand for aluminum increased because of the general industrial development around the world. This trend is straightforward for copper also. But we can not see an increment in aluminum prices like in the copper because aluminum is much more abundant in the world. There is no straightforward increment in the prices of aluminum over the years after 2010. Probably, the increasing demand for aluminum finds itself a required amount of supply because of its easy-to-produce feature.
As you understand that we can interpret the metal prices whether it is an investment tool or not. The investment tools are generally in increment trend over the years just like gold and silver. But in general, other metals are not showing the same “investment trend”. Because their prices are dependent on the supply and demand balance.
The Advantages of Metals in Manufacturing and Engineering
High Stiffness and Strength
Metals are alloyable materials. So by aölloying with other kinds of elements, metals can have superior features. And we can obtain the different features by alloying metals with other elements. Also, we can achieve high stiffness and high strength characteristics of metals with different alloys. And this is a very basic process.
Specific metals with specific alloys have very good energy absorption capacity compared with other engineering materials. For example, cast irons, which is an iron-carbon alloy, have very good damping and toughness characteristics.
Superior Electrical Conductivity
In most electrical devices and electronics, metals are prominent materials that we use in them. Because the superior electrical conductivity feature of metals makes them prominent in these areas.
Superior Thermal Conductivity
In some engineering applications, thermal conductivity is a very important factor in which heat transfer is very important. Metals conduct the heat very well compared with other engineering metals. Because of this feature of metals, they are prominent materials in HVAC applications such as boilers, IC engines, etc.
These are the individual characteristics of metals. In various applications, the requirement of these properties can have in one place. For example in internal combustion engines, there are lots of dynamic and high-speed parts and great heat transfer from cylinders to the outside of the engine. So the materials that we use in internal combustion engines must withstand these dynamic loadings. So they must have very good toughness and strength, and must have very good thermal conductivity. What material you need to use on internal combustion engines will be probably metal.
Refractory Metals in Engineering
Refractory means, the material has superior properties at elevated temperatures. One of the most important examples of refractory metals is Molybdenum(Mo) and Tungsten(W). These materials show very good hardness and strength characteristics at elevated temperatures.
If we talk about Molybdenum(Mo), Mo has a very high melting temperature and relatively dense and stiff material. In such applications, we can use Molybdenum as pure material. Also, we can add small amounts of alloying elements to Molybdenum like titanium and zirconium (less than 1% total). This alloy is named TMZ. Because of Molybdenum’s high-temperature strength, it has very important applications such as heat shield applications, heating elements, electrodes for resistance welding, etc. Also, we can use Molybdenum as an alloying element in steels and superalloys.
Tungsten(W) also has very superior characteristics compared with other metals. The melting temperature of Tungsten is the highest among pure metals. Tungsten is the densest and strongest pure metal. As you know they use Tungsten in incandescent light bulbs as wire. Typical applications of Tungsten are rocket and jet engines and electrodes for arc welding. Also, we use Tungsten widely as an element in tool steels, heat-resistant alloys, and tungsten carbide.
The most important disadvantage of Tungsten and Molybdenum is oxidizing at high temperatures such as 550-600 degrees. If these materials are oxidized, they lost their high-temperature properties. Because of that, some kinds of protective coatings must be applied to Tungsten and Molybdenum parts. Also, they can be used in a vacuumed atmosphere such as the use of Tungsten wire in incandescent light bulbs.
Also, there are other minor refractory metals such as Colombium(Cb) and Tantalum(Ta).
Silver(Ag): Silver has a very attractive appearance that shiny silverish color. Because of this property, Silver is used as coinage and precious jewelry throughout history and today. Also Silver(Ag) has very specific properties. One of these specific properties of Silver is the highest electrical conductivity around metals. Because of this property, Silver can be used in electronical circuits. Also, silver is used as filling in dental applications.
Gold(Au): Gold is one of the most precious metals. Because this precious Gold, it is used in jewelry and coinage throughout history. Gold has a very specific shiny yellow color appearance. Because of this color, Goldis very attractive metal. Gold has also very specific features such as very good electrical conductivity and high corrosion resistance. Because of this, Gold is used in electronical applications. Also, Gold is used in dental work, and plating onto other metals for decorative purposes.
Platinum(Pt): Platinum is the most precious metal of all metals. Because of the expensive nature of Platinum, it is used in jewelry. But applications of Platinum include lots of kinds of areas. These areas include kinds of applications such as thermocouples, electrical contacts, spark plugs, corrosion-resistant devices, and catalytic pollution control equipment for automobiles.
Conclusion About Metals
In this article, we intended to take the topic of metal from a most general viewpoint. We took a look at the metals in terms of chemistry, engineering, industry, economics, and investment. One can understand the importance of metals for human society and civilization. For every people who are dealing with different professions such as industry, economics, investments, or chemistry, it is very important to understand the general characteristics of metals from different viewpoints.
We would like to give some additional information about famous metal bands around the world while speaking about metals but our article’s scope would not allow it…
Do not forget to leave your comments and questions below about the metals in every aspect, according to your viewpoint and profession!
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FAQs About Metals
We can give different kinds of examples of metals. The most important ones are; Iron, Aluminum, Zinc, Magnesium, Copper, Gold, Titanium, Silver, Nickel, and Lithium. They are very important elements of human civilization.
Diamond is not a metal. Diamond is a chemical compound of C2. So, the main element of the diamond is Carbon. And carbon is not a metallic element.
Of the metals, the strongest one is Tungsten. It is very hard the fracturing and very durable for damage. So, there are lots of kinds of engineering applications of this element.
There are lots of kinds of uses of metals. The most important use is the iron-carbon phases that we use in different kinds of structural applications. Around the uses; engineering, finance, commercial uses, and other.
Cesium is a type of metal that is known for its softness. Also, it is the softest metal among others.
Most people think that the heaviest metal is Gold. But it is not like that. The heaviest one is Osmium. The density of the Osmium is around 22.5 g/cm3 which is the highest among others.