黑金属和有色金属Ferrous and Non-Ferrous Metals

lower the melting point alter thermal and electrical properties make a material harder for cutting purposes improve resistance to corrosion help metal to flow better into a cast.
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Industrial processes
Milling machines are used to remove thin layers from a billet (block of material) which is clamped to the bed (base) of the machine. The material is fed past a cutting tool which has many sharp teeth and can remove material quickly. When manufacturers want to make cylindrical products, they use a centre lathe. Metals and plastics can be used on this machine. The work is held in a chuck and a cutting tool is moved towards the work while being held in a tool holder, mounted on the tool post.
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Where do metals come from?
Metals form part of the earth’s crust as metal ore. To obtain useful metals, the metal ore is mined and washed to remove other minerals and unwanted materials. Iron ore is the basis for most steels. To extract pure iron the iron ore is heated in a furnace in a process known as smelting.
The elements of all metals are found naturally in the earth. However, they need to be extracted and processed before they can be used for manufacturing purposes.
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Learning objectives
Learning objectives
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To understand where metals come from and how they are prepared for use. To look at examples of ferrous metals, non-ferrous metals and alloys, and to know the properties of different metals. To understand how heat treatment can change the properties of metals. To be able to use hand tools to work with metals. To be familiar with the industrial processes used to manufacture metal goods.
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Changing the properties of metals
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Heat treatment – hardening steel
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Product Design Ferrous and Non-Ferrous Metals
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A closer look at alloys
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Random alloy generator
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Metals and their properties
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Finishing techniques
Several surface finishing techniques can be used on metals. The most common ones are detailed below: Paint
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A closer look at ferrous metals
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Non-ferrous metals
Non-ferrous metals do not contain iron. These are pure metals used by designers, manufacturers and engineers in a wide variety of applications.
Non-ferrous facts Aluminium is the most common non-ferrous metal, found in abundance in bauxite ore. Non-ferrous metals are not magnetic.
Non-ferrous metals: contain no iron are not attracted by a magnet.
Because metals in their most basic form are natural resources, designers and manufacturers need to be careful and socially responsible about how much they use, and reuse or recycle metals where possible.
square hexagonal
square tube angle channel sheet
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octagonal
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Categories of metals
Metals can be broken down into these main categories:
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Background on metals
Metals are common in manufacturing today. From building and construction work to vehicles and leisure products, they are a vital material for product designers and engineers.
Ferrous metals are obtained from iron ore. You might recognize the letters ‘Fe’ from the periodic table, where they represent iron.
Ferrous facts Iron replaced bronze as the principal metal by 1000 BC. Early pots and pans made from iron poisoned the users! Early steels were made by adding carbon to iron as it was melted over a charcoal fire. Ferrous metals: contain iron will corrode unless protected are attracted by a magnet are strong, rigid and cheap.
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Primary processes – rolling
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Primary processes – extrusion
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Stock forms of metals
Heat treatment – tempering
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Heat treatmen源自文库 – annealing
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Working with metals – hand tools
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Metals are available in several raw forms. Each form is suitable for different manufacturing processes depending on the type of equipment used, the cost of the metal, the scale of production and the properties of the finished product. round rod flat strip round tube
Ferrous metals
Non-ferrous metals
Pure metals do not contain any other metals or elements.
Pure metals
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Alloys
Alloys
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Ferrous metals
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A closer look at non-ferrous metals
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Alloys
Sometimes ferrous and non-ferrous metals require different properties in order to function better in specific situations. Alloying metals involves mixing two or more metals and other elements to improve their properties. Alloying metals can: