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Engineering, Contents List - Coggle Diagram
Engineering
Materials
Low/high carbon steels
Stainless Steel, Aluminium: Alloying with elements like Carbon (in steel) or Chromium (in stainless steel) increases Strength and Hardness but generally decreases Ductility and Malleability; for instance, Chromium forms a passive oxide layer giving Stainless Steel its excellent Corrosion resistance.
Heating/Cold working
Heating metal followed by slow cooling (Annealing) increases Ductility and Malleability by relieving internal stress, while Cold Working (mechanical deformation) increases Hardness and Strength through strain hardening, at the cost of reduced ductility.
Hardening and Quenching
Rapid cooling of hot carbon steel creates a very high Hardness but leaves the metal brittle, lacking Toughness; conversely, Corrosion is the chemical breakdown that reduces the metal's effective Strength.
Corrosion
Where the surface of the metal reacts with its environment. e.g. Rusting & where aluminium reacts with air to form an oxide layer that protects the metal from further corrosion. The layer is so thin that it cannot be seen by the naked normally
Toughness/brittleness
The opposite of toughness is brittleness. A tough material will withstand an impact without breaking. A brittle object will shatter on impact.
Tough materials will bend but not crack.
Brittle materials will crack or shatter.
Ductility
Ductile materials are stretched by applying a tensile force. A non-ductile force will break rather than stretch when a tensile force is applied.
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Strength & Stiffness
The stronger a material and the stiffer is the more it resists deforming. Stiffness is affected by the shape of the material.
Processes
VULCANISING
The vulcanization process involves adding and heating rubber with sulfur to improve its elasticity and strength. This is to form cross-links between the individual polymer chains.
Turning (Lathe)
Definition: Turning is the process of removing unwanted material from a rotating workpiece using a stationary, single-point cutting tool.
Riveting vs Welding
Welding joins materials by applying intense heat to melt the edges of the pieces together, often using a filler material. When it cools, the pieces are fused into a single, continuous unit.
Riveting joins materials using a special metal fastener called a rivet. The rivet is put through a hole in both pieces and the end is hammered or pressed (bucked) to make a second head, securely clamping the materials together
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Injection moulding
A process where molten material (usually plastic, known as a polymer) is forced under high pressure into a mould cavity (a hollow shape) and allowed to cool and solidify, creating a finished product.
Hand Working Metals
This process involves using tools like scribers to transfer a design onto metal (Marking Out), then securing the material to remove waste using hand tools (files, hacksaws) to achieve the final shape, with the secure clamping of the material in a vice being the primary safety step against injury.
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Composites
A type of material made by combining two or mire different types of material which remain physically distinct within its structure.
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Contents List
Materials, Composites, Turning, Properties of materials, Electronic
components, Young’s modulus, Stress and strain, Working properties of metals, Marking and
Measuring tools, Riveting, Welding, Mechanisms and MA, Vulcanising, Injection moulding,
Pneumatic systems, Force calculations, Flow diagrams, Interface drivers, Performance testing,
Lifespan and impact of engineered products, Maths, Safety precautions