A technique similar to plastic injection moulding is adding an extra spur to the already buoyant powder metallurgy market.
Known as metal injection moulding, it can achieve densities of 95% or more, resulting in parts with mechanical properties superior to standard powder metallurgy ones. In the UK it has been pioneered by Cheshire-based Metal Injection Mouldings.
The process involves mixing the metal powder with a plastic binder and injecting it into the mould. The resulting part then goes through a debinding process and sintering.
Like plastic injection moulding, the process is ideal for the high-volume production of complex 3D shapes. It is often the best alternative to investment casting where fine detail and close tolerances are involved. It is best suited to making parts smaller than 150mm in any dimension, weighing less than 100g, in 10,000-a-year-plus volumes.
The technology can only be used with certain metals, such as low alloy and stainless steels, nickel and cobalt alloys, magnetic alloys, tool steels and bronze. But it has a wide range of applications, from stainless steel gears for electric toothbrushes to small parts for weapons, computers and automotive transmissions.