8 common metal materials

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1 Cast iron – fluidity. As an unnoticeable part of our daily environment, sewer covers are rarely noticed by people. Cast iron is used in such large numbers and across a wide range of applications primarily due to its excellent fluidity and its ability to be cast into various complex shapes. Cast iron is actually the name given to a mixture composed of various elements, including carbon, silicon, and iron. The higher the carbon content, the better its flow properties during casting. Carbon appears here in the forms of graphite and iron carbide. The presence of graphite in cast iron gives sewer covers excellent wear resistance. Rust usually appears only on the outermost layer, so it is generally polished off. Nevertheless, special measures are taken to prevent rusting during the casting process; namely, an asphalt coating is applied to the surface of the casting, with the asphalt penetrating into the pores in the surface of the cast iron, thereby providing rust protection. The traditional process for producing sand mold casting materials is now being used by many designers in other, newer and more interesting fields. Material properties: excellent fluidity, low cost, good wear resistance, low solidification shrinkage, high brittleness, high compressive strength, and good machinability. Typical applications: Cast iron has been used for hundreds of years in various fields, including construction, bridges, engineering components, household items, and kitchenware. 2 Stainless steel – An alloy of love. Stainless steel is an alloy created by adding chromium, nickel, and other metal elements to steel. Its rust-resistant property stems from the chromium content in the alloy; chromium forms a tough, self-repairing layer of chromium oxide on the surface of the alloy, a layer that is invisible to the naked eye. The typical ratio of stainless steel to nickel that we refer to is 18:10. “The term “stainless steel” does not refer to just one type of stainless steel; rather, it denotes more than a hundred industrial grades of stainless steel, each of which exhibits excellent performance in its specific area of application. At the beginning of the 20th century, stainless steel was introduced into product design, and designers created many new products taking advantage of its durability and corrosion resistance, entering many fields that had not been explored before. All of these design attempts were highly revolutionary: for example, devices that could be reused after disinfection appeared for the first time in the medical industry. Stainless steel is divided into four main types: austenitic, ferritic, ferritic-austenitic (composite), and martensitic. The stainless steel used in household items is basically austenitic. Material properties: suitable for healthcare applications, corrosion-resistant, capable of precise surface treatment, high rigidity, can be shaped using various processing techniques, difficult to work with through cold processing. Typical applications: Among the commonly used primary-color stainless steels, austenitic stainless steel is the most suitable material for coloring, allowing for satisfactory colored appearances and shapes to be achieved. Austenitic stainless steels are primarily used in decorative building materials, household items, industrial pipes, and building structures; martensitic stainless steels are mainly used for manufacturing knives and turbine blades; ferritic stainless steels possess corrosion resistance and are used in washers designed for long-term use as well as in boiler components; composite stainless steels have even better corrosion resistance, which is why they are often used in aggressive environments. 3 Zinc – 730 pounds throughout a lifetime. Zinc has a silverish appearance with a slight blue-gray tint; it is the third most widely used non-ferrous metal after aluminum and copper. A statistic from the U.S. Geological Survey shows that an average person consumes a total of 331 kilograms of zinc over the course of their lifetime. Zinc has a very low melting point, so it is also an excellent material for casting. Zinc castings are very common in our daily lives: they are used as the material beneath the surface layers of doorknobs and faucets, as well as in electronic components. Zinc possesses extremely high corrosion resistance, and this property endows it with another essential function – that of serving as a coating material for steel surfaces. In addition to these functions, zinc is also an alloying element used together with copper to form brass. Its corrosion resistance is not only applied to steel surface coatings – it also helps strengthen our human immune system. Material properties: suitable for healthcare applications, corrosion-resistant, excellent castability, outstanding corrosion resistance, high strength, high hardness, low cost of raw materials, low melting point, creep resistance, easy to form alloys with other metals, health-promoting properties, fragile at room temperature, yet ductile at around 100 degrees Celsius. Typical use: electronic product components. Zinc is one of the alloying materials used to form bronze. Zinc also has cleaning and hygienic properties as well as corrosion resistance. Additionally, zinc is also used in roofing materials, photo engraving discs, mobile phone antennas, and the shutter mechanisms in cameras. 4 Aluminum (AL) – Modern Materials. Compared to gold, which has been in use for 9,000 years, aluminum, this white metal with a slight blue tint, can truly be considered a newcomer among metallic materials. Aluminum was discovered and named in the early 18th century. Unlike other metal elements, aluminum does not exist in nature as a pure metallic element; instead, it is extracted from bauxite, which contains 50% aluminum oxide (also known as alumina). Aluminum that exists in minerals in this form is also one of the most abundant metallic elements on our planet. When aluminum first appeared as a metal, it was not immediately put to use in people’s lives. Later on, a range of new products featuring its unique functions and properties were introduced, and this high-tech material gradually gained an increasingly broad market. Although aluminum has a relatively short history of use, the production volume of aluminum products in the market today far exceeds that of all other non-ferrous metal products combined. Material properties: flexible and malleable, easy to alloy, high strength-to-weight ratio, excellent corrosion resistance, good electrical and thermal conductivity, recyclable. Typical uses: vehicle frames, aircraft components, kitchen utensils, packaging, and furniture. Aluminum is also often used to reinforce large building structures; for example, the Statue of Venus on Piccadilly Square in London, as well as the top of the Chrysler Building in New York, have all been reinforced with aluminum materials. 5 Magnesium Alloys – Ultra-thin aesthetic design. Magnesium is a highly important non-ferrous metal; it is lighter than aluminum and can form high-strength alloys with other metals. Magnesium alloys have advantages such as low density, high specific strength and stiffness, good thermal and electrical conductivity, excellent damping and electromagnetic shielding properties, ease of processing, and ease of recycling. However, for a long time, due to high costs and technical limitations, magnesium and its alloys have been used only sparingly in the aerospace and **industries; hence they are known as the “noble metals”. Today, magnesium is the third most important metallic engineering material after steel and aluminum, and is widely used in fields such as aerospace, automotive, electronics, mobile communications, and metallurgy. It is foreseeable that due to the increasing production costs of other structural metals, magnesium will become even more important in the future. Magnesium alloys have a specific gravity of 68% that of aluminum alloys, 27% that of zinc alloys, and 23% that of steel; they are commonly used in automobile parts, casings for 3C products, building materials, etc. Most ultra-thin laptop and phone casings use magnesium alloy for their shells. Since the last century, humans have maintained an undeniable fondness for the texture and luster of metals. Although plastic products can mimic a metal-like appearance, their luster, hardness, thermal properties, and texture still fall short compared to those of metals. As a new type of metal raw material, magnesium alloy gives the impression of being a high-tech product. The corrosion resistance of magnesium alloys is 8 times that of carbon steel, 4 times that of aluminum alloys, and more than 10 times that of plastics. They possess the best anti-corrosion properties among all alloys. Commonly used magnesium alloys are non-flammable; especially when used in automotive and motorcycle parts as well as building materials, they can prevent sudden combustion. Magnesium ranks 8th in terms of abundance in the Earth’s crust. Most magnesium raw materials are extracted from seawater; therefore, its resources are stable and abundant. Material properties: lightweight structure, high rigidity and impact resistance, excellent corrosion resistance, good thermal conductivity and electromagnetic shielding, good non-flammability, poor heat resistance, and easy to recycle. Typical applications: Widely used in aerospace, automotive, electronics, mobile communications, metallurgy, and other fields. 6 Copper – Man’s Companion. Copper is truly an incredible versatile metal, and it is deeply intertwined with our lives. Many of the early tools and weapons made by humans were made of copper. Its Latin name, “cuprum”, originates from a place called Cyprus, an island rich in copper resources. People used the abbreviation Cu from the island’s name to name this metal, and thus copper acquired its current name. Copper plays a very important role in modern society: it is widely used in building structures and as a medium for transmitting electricity. Additionally, for thousands of years, it has been used by people from many different cultural backgrounds as a raw material for making body ornaments. From its initial use in simple decoding and transmission, to the crucial role it now plays in complex modern communication applications, this malleable, orange-colored metal has accompanied our development and progress every step of the way. Copper is an excellent conductor of electricity; its electrical conductivity is second only to that of silver. In terms of the history of human use of metal materials, copper is the metal most long-used by humans after gold. This is largely because copper mines are easy to extract, and copper can be relatively easily separated from them. Material properties: excellent corrosion resistance, outstanding thermal and electrical conductivity, hardness, flexibility, ductility; it presents a unique appearance after polishing. Typical uses: wires, engine coils, printed circuits, roofing materials, piping materials, heating materials, jewelry, cooking utensils. It is also one of the main alloying elements used in the production of bronze. 7 chromium – post-treatment for high gloss. The most common form of chromium is found as an alloying element in stainless steel, where it enhances the hardness of the steel. The chrome plating process is generally divided into three types: decorative coatings, hard chromium coatings, and black chromium coatings. Chromium plating is widely used in the engineering field. Decorative chromium plating is usually applied as the outermost layer on top of the nickel layer, offering a finely polished finish similar to that of a mirror. As a decorative post-treatment process, the thickness of the chromium plating is only 0.006 millimeters. When considering the use of chromium plating, it is essential to fully take into account the dangers associated with this process. Over the past decade, there has been an increasingly clear trend toward replacing hexavalent decorative chromium solutions with trivalent chromium solutions, as the former is highly carcinogenic, whereas the latter is considered to have relatively lower toxicity. Material properties: very high surface finish, excellent corrosion resistance, hard and durable, easy to clean, low friction coefficient. Typical uses: Decorative chromium plating is used as a coating material for many automotive components, including door handles and bumpers. In addition, chromium is also applied to bicycle parts, bathroom faucets, as well as furniture, kitchen utensils, and tableware. Hard chromium plating is more commonly used in the industrial sector, including random access memory in control units, components of jet engines, plastic molds, and shock absorbers, among others. Black chrome plating is mainly used for instrument decoration and in solar energy applications. 8 Titanium – Light yet strong. Titanium is a very special metal: it is extremely lightweight, yet at the same time highly durable and resistant to corrosion. It retains its original color for life at room temperature. Titanium has a melting point similar to that of platinum, which is why it is often used in aerospace and military precision components. With the addition of current and chemical treatment, different colors are produced. Titanium possesses excellent resistance to acid and alkali corrosion; titanium that has been immersed in aqua regia for several years remains shiny and bright. If titanium is added to stainless steel, even in an amount of about one percent, it **improves its resistance to rusting. Titanium possesses excellent properties such as low density, high temperature resistance, and corrosion resistance. The density of titanium alloys is half that of steel, yet their strength is similar to that of steel; titanium can withstand both high and low temperatures. It maintains high strength over a wide temperature range of -253°C to 500°C. These advantages are precisely what space metals require. Titanium alloys are excellent materials for manufacturing the casings of rocket engines, as well as satellites and spacecraft; they are known as the \"metal of space\". Due to these advantages of titanium, it has since the 1950s become a prominent rare metal. Titanium is a pure metal; it is precisely because of its purity that no chemical reaction occurs when materials come into contact with it. In other words, due to titanium’s high corrosion resistance and stability, its properties remain unchanged even after long-term contact with humans, so it does not cause allergies. It is the only metal that has no effect on the human autonomic nervous system or sense of taste, and it is referred to as a \"biocompatible metal\". The biggest drawback of titanium is that it is difficult to extract. This is mainly because titanium can combine with oxygen, carbon, nitrogen, and many other elements at high temperatures. Therefore, titanium was once considered a \"rare metal\"; in fact, its abundance in the Earth’s crust is about 6‰, which is more than 10 times higher than the combined abundance of copper, tin, manganese, and zinc. Material properties: very high strength, excellent corrosion resistance per unit weight, difficulty in cold working, good weldability, about 40% lighter than steel and 60% heavier than aluminum, low electrical conductivity, low thermal expansion coefficient, and a high melting point. Typical applications: golf clubs, tennis rackets, laptops, cameras, suitcases, surgical implants, aircraft frames, chemical equipment, and marine equipment, etc. Additionally, titanium is also used as a white pigment required in paper, painting, and plastics.