Metal properties

Metal properties

ГБПОУ ВО «Воронежский политехнический техникум»

Ермаков Сергей Алексеевич

Преподаватель иностранного языка

Metal properties

• All metals and alloys created on their basis are divided into two large groups with different properties:

• Ferrous metals - steel
• Non-ferrous metals - copper, bronze, brass, zinc, tin, aluminum, lead and silver.

Steel

• Steel refers to ferrous metals. Carbon steel, which is an alloy of iron with carbon and other elements, is best suited for artistic processing. Steel has high quality characteristics, among which are the following:
• Elasticity
• Strength
• The ability to harden - a piece of steel is heated at high temperature red-hot, and then dipped in water. Due to this, the metal acquires various degrees of hardness and elasticity.
• The possibility of "letting go" by heating to red heat and then slowly cooling.
• Ability to be machined with a blacksmith hammer in a heated state, as the steel is excellent forged.
• The ability to cut metal into thin strips.

Non-ferrous metals

• Non-ferrous metals are much more expensive than ferrous, because they have many unique properties. The main one is the lack of reaction with the magnet, that is, non-ferrous metals are not attracted and are not magnetized. In addition, most of them are practically not oxidizable, so the products are characterized by a long service life.
• Non-ferrous metals for artistic processing are produced in various forms:
• Ribbons
• Stripes
• Ingots
• Handsets
• Wire
• Rods
• Sheets

Copper

• Copper is a fairly soft metal of a beautiful red - orange hue, characterized by an increased ability for forging and having great electrical conductivity and the ability to conduct heat. Copper processing is not particularly difficult, but the master must keep in mind the high viscosity of this metal.

Bronze

• Bronze is an alloy of copper with tin. The quantitative content of tin affects the color of the alloy, which can take on pink, red, yellow or gray shades. If the bronze product is covered with a layer of patina (decorative plaque of copper oxide), then it acquires a noble smoky-greenish hue and looks old and really expensive. Bronze is most often used for inlay and foundry work.

Brass

• Brass is an alloy of copper and zinc. The hue of the metal depends on the amount of zinc. By its quality characteristics, brass is a harder alloy than pure red copper, so its malleability is much lower. Compared to copper, brass has some fragility, but at the same time it is more elastic.

Zinc

• Zinc - perfect for casting both in pure form and in alloys with other metals. Pure zinc is poorly forged, but it is easy to solder, engrave and process with various tools. The melting point is 419 * C.

Tin

• Tin is a non-ferrous metal that has long been known for its softness and ductility. Its melting temperature is only 252 * C. As a component, tin is part of various types of bronze. At a break, tin emits a characteristic, recognizable crunch. Pure tin and its alloys are ideal for making inlays. And tin is used for tinning and soldering utensils both in pure form and in alloys with lead. Moreover, the products of its oxidation are harmless.

Aluminum

• Aluminum is a non-ferrous metal of silver-white color, which melts at a temperature of about 658 * C. A characteristic feature of aluminum is its lightness and simplicity in metal processing. Cast aluminum is quite fragile, and in the rolled (annealed) form, it acquires the desired ductility.

Lead

• Lead is a soft non-ferrous metal with a bluish-gray hue. It melts at a temperature of 327 * C, and well resists corrosion. However, it should be noted that lead oxides are poisonous. Lead is suitable for foundry work and the manufacture of molded products.

Silver

• Silver - also refers to non-ferrous, but it is also a precious metal. Pure silver is too soft and therefore inconvenient to process. For the manufacture of products used in the form of alloys with copper. Silver inserts are used in inlays, in engraving, coinage and mobile.

Metal properties

• Durability of metal - ductile ductile metals require greater cutting forces, but their viscosity must be taken into account. A piece of copper or lead needs to be chopped to the end, and brass, zinc or steel can be chopped with a chisel, and then simply broken. Harder brass when turning gives a smooth surface, while aluminum or copper, as it were, reach for the cutter.
• Fragility is the ability of solid materials to collapse due to mechanical stress without noticeable plastic deformation. This property is the opposite of plasticity. Highly hardened steel, as well as many grades of brass and bronze are very fragile, and from strong impacts they break into pieces. The brittleness of a metal is not always a sign of its hardness, for example, zinc casting is brittle, but not hard. The hardened steel knife is both hard and brittle.
• Elasticity is the property of metals to restore their shape and volume after the termination of external forces or heating, which caused deformation. To a large extent, this property is possessed by special grades of steel.

Thanks for attention!