Domestic appliances, such as televisions, washing machines and fridges, all use circuit boards to control the components needed to complete their various functions, eg timers or alarms. To increase functionality, these products may also have microcontrollers that make decisions based on the input. For example, some washing machines sense the weight of wet clothes and adjust the speed it spins the clothes at.
Domestic white goods, such as washing machines and freezers, are usually encased with a steel shell that is dip coated in a plastic coating, which protects it from wear and rust, insulates it and makes it easy to keep clean. Drive belts, which turn washing machine drums and oven fans, are made from rubber or polyurethane plastic as it is hardwearing and flexible.
Mechanical products are generally made of metal for strength and resistance to abrasion. The repetitive movement from engine pistons is a good example, where the piston must be resilient enough to withstand the friction and the buildup of heat produced by constant motion.
High-carbon steel is often used for the housing of moving parts in mechanical products as it is hardwearing, smooth and resistant to rust. It is used in car brakes and wheels. To cut down on weight, some components, such as engine blocks in sports cars, are made from aluminium, which can improve the performance of the car but is expensive.
Car engines can get very hot, so the metals used in their production need to be able to withstand high temperatures. Alloys of metals, such as stainless steel, which is a mixture of low-carbon steel and chromium, can be made to maximize their efficiency and produce certain properties. Stainless steel is resistant to rust, smooth, hardwearing and can be polished to a high shine.