Braking Methods

Modern brakes were invented in the late 19th century, around the same time as the tyre. Up until then, vehicles had wooden wheels that were stopped by large wooden blocks, lowered into position by the driver using a simple lever system. When tyres were invented, the wooden block system wasn't good enough to stop them at the higher speeds they could achieve, which meant that a new braking system had to be invented.

To see the basic principles of modern braking, it is easiest to look at a bicycle. Basically, when you put pressure on the brakes, the pressure is transferred through cables to pull small pads onto the side of the tyres, and the force of the friction against the tyres causes them to stop.

In fact, cars originally used this very same cable system, but it was found not to work so well at high speeds. Instead, the cables were replaced with hydraulic fluid, which works to transfer the pressure the driver puts on the pedal to the brakes. This works because the fluid cannot get much smaller when pressure is put on it, meaning that pressure at one end is transferred to the other - much like water flowing through a pipe. However, if this brake fluid leaks even a little, then the brakes may not work properly any more, which is why it's very important to check your brake fluid regularly.

Of course, in modern cars, there are other mechanisms apart from pure pressure to help you brake. Most cars now have a vacuum system to create more friction in the brakes, and a servo system that uses the car's own speed to help your pressure have more of an impact.

One word of warning, though: some cars now have fully computerised brakes, where pushing on the pedal sends an electrical signal to turn on electrically-powered brakes. While this makes it much easier to brake, it is also more prone to failure, meaning that if your car's computer breaks you might find it impossible to stop. Until this technology has been around a little longer, it's probably best to stick to traditional mechanical braking methods.

Magnesium Forming Methods

After magnesium is extracted, refined, and made into an alloy, it is time to form the magnesium alloy into materials used in structural engineering. Today, there are many advances in alloy forming, in the area of magnesium sheet technology. The sheets are used increasingly to replace other metals like iron and aluminum. The new sheets are formed using heat, but other magnesium alloy materials are formed using one of five methods: hot, cold, press brake, stretch, and drop hammer.

Hot Forming

Heat is the optimum tool for forming magnesium alloys. Magnesium sheeting especially requires high heat. The sheets are formed at various thicknesses without sacrificing strength. The process is performed by applying heat to the lump of metal while applying pressure to shape the hot metal. Only light pressure is required compared to other processes. Alloys are often produced from hot forming. Hot forming processes allow magnesium sheeting and other manufacturers the opportunity to create a high volume without sacrificing product quality. The Innovative Thixomolding technique used to make magnesium alloy sheet is a heat forming process.

Stretch Forming

This is another hot forming technique. The metal is stretched at very high temperatures over forms to shape it. In some cases, the tools used to shape the metal alloy are heated using radiant heat. This is a way make metal products without the wrinkles.

Drop Hammer Forming

To make asymmetrical shapes, shallow forms, and other custom shapes, drop-hammer forming is used. This also is a hot formed die shaping technique. It uses high heat and is a way to reduce shrinking after the metal is shaped.

Cold Forming

This category of forming processes is not used on magnesium often. It is reserved for making slight adjustments in shaping the metal, as it does not form well at all without heat. The metal in wire form is bent and pulled at high speeds. Magnesium alloys shorten during cold forming; so slight bends and alterations are made.

Press Brake Forming

Magnesium sheets can be formed into cones, cylinders, rings and into angles and other custom shapes. The alloy is placed in a machine where it is pressed with a die to make the wanted shapes. The dies are made of steel or rubber (if it is to be cold formed). A gas torch is used to heat the metal as needed. The press used can be hydraulic in forming magnesium alloys with rubber dies. This method is more of a shaping process for the material.

This is a general overview of the categories of processes used to shape magnesium alloy, especially magnesium sheets. The primary difference between the use of these processes on magnesium and other alloys is the need for heat in order to significantly form the magnesium alloys.