Ground-up e-waste could be used to make steel stronger
Electronic waste can be difficult to repurpose, as it often consists of two or more mixed materials. Now, however, Australian scientists have developed a method of converting so-called e-waste into a protective coating for steel.
When you look at the inner workings of a device such as a smartphone, you'll see that it consists of many tiny joined components, made of materials such as silicon, plastic and metal. Manually separating these parts from one another and then sorting them for recycling is a fiddly, time-consuming and costly process. As a result – although some alternatives are in the works – it often simply isn't done.
Working at the University of New South Wales, Veena Sahajwalla and Rumana Hossain set out to address that problem.
They started by grinding the glass and plastic from discarded computer monitors into a powder, then heating that powder to 2,732 ºF (1,500 ºC). This caused the powder to form into silicon carbide nanowires, which were subsequently mixed with particles of ground-up circuit boards. A layer of that mixture was then placed on a steel substrate and heated to 1,832 ºF (1,000 ºC). Doing so melted the copper in the circuit board particles, forming an enriched silicon-carbide hybrid layer that bonded to the steel's surface.
Lab tests showed that the addition of that layer increased the steel's hardness by 125 percent. The layer was durable, too, as microscope images showed that it remained firmly attached to the steel after being struck by a nanoscale indenter – and no cracking or chipping of the hybrid coating occurred.
A paper on the research was recently published in the journal ACS Omega.
Source: American Chemical Society