Non-metallic materials:

Ceramics – This class may be defined as any inorganic, non-metallic solids processed or used at high temperature. For example pottery, sanitary white ware, tiles, table china etc. And also the more high-tech applications of oxides, carbides and nitrides. Many of these are of great industrial interest. Ceramics also include materials such as glass, graphite, cement and concrete.

Semiconductors – this is a special category of non-metallic inorganic material. Its electrical resistivity is between that of insulators and conductors. These materials are the building blocks of transistors, solar cells, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier and digital and analog integrated circuits.

Polymers -  are materials comprised of long molecular chains where simple molecules, often carbon-hydrogen groups, are joined by strong covalent bonds. Besides plastics, polymers are the basis of paint, rubber and synthetic fibre industry.

Metallic materials:

The most used metallic materials are steel and cast iron, aluminium and its alloys, copper and its alloy, tin, zinc, lead, wolfram, titanium. Metal is not only used for productions components but also for working and shaping of products.  Metallic materials are also widely used as connecting material, making plating and as alloyed elements for steel.

The best known materials in engineering are steel and cast iron. They are manufactured by mixing iron and carbon in a specific ratio. Steel contains carbon up to 2% and cast iron more than 2%.

Steel – alloy of iron and carbon. Steel that contains less than 0,8% carbon is called hypoeutectoid, and any steel with more than 0,8% carbon content is hypereutectoid. Higher carbon content increases hardness and strength and improves hardenability.

The physical properties of steel include high strength, low weight, durability, flexibility, electrical conduction and corrosive and oxidation resistance. These can be changed by adding certain alloys like chromium, nickel, manganese, molybdenum, wolfram and other elements. For example chromium can reduce corrosion resistance of steel and manganese soften the steel structure and thus increases the solidity.

Objects made of iron or steel are attracted to the magnet, because iron is a ferromagnetic element.

These materials are so versatile that they can be formed into complex shapes, joined by welding and heat treated to impart useful combinations of toughness and strength.

Cast iron – is an alloy of iron (more than 95% by weight) and other elements. The main alloying elements are carbon and silicon.  Cast iron tends to be brittle, except for malleable cast irons. With its low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast iron have become an engineering material.

Aluminum – is remarkable for its ability to reset corrosion, light weight and for the metal’s low density. It is the most widely used non-ferrous metal. Structural components made from aluminium and its alloys are important especially is aerospace industry but also in other areas of transportation and building.  The most popular aluminium alloy is duralumin because of its light weight and strength.

Copper – malleable and ductile metal. It is a good conductor of heat and electricity. It is used mostly for making of electrical cables and in building industry as sheet copper. Copper is too soft in comparison to steel, so it’s often incorporated in alloys. They have higher resistance to corrosion. The copper alloys are brass (copper with zinc) and bronze (copper with tin).

Titanium – has the highest strength-to-weight ratio of any metal. It has a low density. It is strong, lustrous and corrosion-resistant also to sea water. Titanium and its alloys are used in aerospace, marine and car industry.

Semi-finished products

Semi-finished products are partly machined shapes that later are manufactured into finished products. A semi-finished products should be as much as possible similar to a finished product.

When normalized semi-finished products are used, the production becomes cheaper. Normalized semi-finished products are rough-machined and used in piece production and short run production. Unnormalized semi-finished products are used in series production and mass production. They are often made according to the customer’s specifications and therefore they are designed precise with small machining allowance.

Normalized semi-finished products:

• Strips
•   Blanks (blooms, billets etc.)
•   Plates
•   Bars (circle, square, I, U-shaped)
•   Pipes
• Thin-walled profiles

Blanks, bars and plates are produces by hot rolling or cold rolling and can be also calibrated by die drawing. Pipes are made by bending and welding sheets od plates, weldless pipes have to be rolled in a special way or extruded and then die drawn. Die drawing is also used to produce wires.

Unnormalized semi-finished products: