Oxford, May 22, 2012 - Researchers in Ireland have developed a new technology using materials called bulk metallic glasses to produce high-precision molds for making tiny plastic components. The components, with detailed microscopically patterned surfaces could be used in the next generation of computer memory devices and microscale testing kits and chemical reactors.
In their article published in the latest edition of the open access journal Materials Today, Michael Gilchrist, David Browne and colleagues at University College Dublin explain how bulk metallic glasses (BMGs) were discovered about thirty years ago. These materials are a type of metal alloy, but instead of having a regular, crystalline structure like an everyday metal such as iron or an alloy like bronze, the material's atoms are arranged haphazardly. This disordered, or amorphous atomic structure is similar to the amorphous structure of the silicon and oxygen atoms in the glass we use for windows and drinking vessels.
The haphazard arrangement of atoms in BMGs means that they have some very different mechanical properties from conventional metals. They can be heated and molded like plastics and they can be machined with microscopic precision below the grain size of conventional metals. BMGs also retain the strength and durability of normal metals.
Gilchrist and his colleagues have now exploited the haphazard nature of the atoms in BMGs to allow them to machine microscopic features on to the surface of a BMG. This is not possible with conventional metals such as tool steel used in molds which cannot typically be machined with better than 10 micrometer precision because of its crystalline grain structure. They have then used the resulting strong and durable metallic devices to carry out injection molding of plastic components with microscopic surface patterns using a straightforward tool production route.
"Our technology is a new process for mass producing
|Contact: Stewart Bland|