JC Engineering

Vocabulary practice cards covering engineering materials, properties, mechanisms, heat treatments, and electronics based on transition revision notes.

Steel

A mixture of iron and carbon.

Stainless steel

A mixture of iron and chromium that does not rust.

Cast iron

A brittle metal used for engine blocks.

Aluminium

A lightweight, corrosion-resistant, and good conductor used in vehicles, aircraft, and drink cans.

Copper

A highly conductive metal used in electrical wiring.

Brass

An alloy of copper and zinc used for doorknobs, plumbing fittings, and musical instruments.

Bronze

An alloy of copper and tin used in medals, bearings, and sculptures.

Ferrous metals

Metals that contain iron, such as steel and cast iron, and can rust.

Non-ferrous metals

Metals containing no iron, such as aluminium and copper, which are rust-resistant.

Alloys

A mixture of two or more metals (or a metal and non-metal) combined to improve properties.

Hardness

The ability to resist surface indentation, scratching and wear.

Toughness

The ability to withstand shock and impact without fracturing.

Elasticity

The ability to return to original shape after being stretched or compressed.

Plasticity

The ability to be permanently deformed without fracturing.

Ductility

The ability to be drawn into wire or plastically deformed without fracturing.

Malleability

The ability to be hammered or rolled into thin sheets without rupturing.

Brittleness

A property where a material fractures easily when subjected to stress or sudden impact; the opposite of toughness.

Conductivity

A property that allows heat or electricity to pass through a material.

Transparency

A property that allows light to completely pass through a material.

Tensile strength

The ability to resist being pulled apart (tension).

Fatigue

The weakening of a material caused by repeated loading or stress cycles over time.

Thermoplastics

Plastics that soften when heated and can be reshaped repeatedly, such as PVC, nylon, and acrylic.

Thermosetting plastics

Plastics that harden permanently when first heated and cannot be re-melted, such as bakelite and epoxy resin.

Smart materials

Materials that change properties in response to external stimuli, like thermochromic materials or shape memory alloys.

Thermochromic materials

Materials that change colour with temperature.

Shape memory alloys

Materials that return to their original shape when heated.

Anodising

An electrochemical process that thickens the natural oxide layer on aluminium to increase corrosion resistance.

Galvanising

The process of coating steel with zinc to prevent rust.

Powder coating

An electrostatically applied powder that is baked to form a hard finish.

Hardening

Heating metal to critical temperature (approx. $760°C$ for steel) then quenching in water or oil to create a hard but brittle surface.

Tempering

Reheating hardened metal to $200–300°C$ and cooling slowly to reduce brittleness while retaining hardness.

Annealing

Heating metal to critical temperature and cooling very slowly to soften it and relieve internal stresses.

Normalising

Heating metal above critical temperature and cooling in still air to relieve stress and refine grain structure.

Tension

A pulling or stretching force.

Compression

A squashing or pushing force.

Shear

A sliding or cutting force where two opposite forces act on the same plane.

Torsion

A twisting force.

Bending

A combination of tension and compression forces.

Rack and pinion

A mechanism that converts rotary motion to linear motion.

Crank and slider

A mechanism that converts rotary motion to reciprocating (back and forth) motion.

Worm and worm wheel

A self-locking mechanism used for large speed reduction in a compact space.

Ratchet and pawl

A mechanism that allows motion in one direction only.

4-Stroke Engine Order

1. Intake/Induction, 2. Compression, 3. Power/Combustion, 4. Exhaust.

Crankshaft

A component that converts the reciprocating motion of the piston to rotary motion.

LED Polarity

The longer leg is the positive (anode) and the shorter leg/flat side is the negative (cathode).

Flux

A chemical agent that cleans oxide layers from metal and prevents re-oxidation during soldering.

AND gate

A logic gate where the output is 1 only when BOTH inputs are 1.

OR gate

A logic gate where the output is 1 when AT LEAST ONE input is 1.

Ohm's Law

$V = I \times R$ (Voltage = Current $\times$ Resistance).

Servo motor

A motor with built-in position feedback that moves to and holds a precise angle.

DPDT switch

Double Pole Double Throw switch; allows two separate circuits to be switched simultaneously.

Ergonomics

The design of products to fit human use, focusing on comfort, usability, and safety.

Gantt Chart

A project management bar chart used to plan, schedule, and track tasks against time.

CNC

Computer Numerical Control; computer-controlled machining for precision and repeatability.

Upcycling

Reusing or repurposing an old product into something of equal or higher value.

Facing

A lathe process involving cutting the end face of a workpiece flat.

Knurling

A lathe process of pressing a pattern into a surface to create grip.