Scientists develop anchorless selective laser melting process

Scientists at Sheffield University believe they can eliminate the need for ‘anchors’ used in additive manufacturing.

Additive manufacturing is a process that is used to build up 3D objects, layer by layer, from 3D computer-aided design (CAD) files using a laser to melt fine metal powder to create parts.

‘One of the difficulties when you build parts layer by layer like this is that you need to have a supporting, or anchor, structure around the part, so that if you build any overhanging features they can be held in place,’ principal investigator Neil Hopkinson told The Engineer.

The anchor has traditionally restricted geometric freedom when designing products and also added further costs and labour time to projects.

Hopkinson and his team have developed a process called anchorless selective laser melting (ASLM) that allows them to create parts without the need for anchors.

‘The process involves melting dissimilar materials to form a eutectic system alloy, which allows the traditional stresses to be reduced when building parts,’ said Hopkinson. ‘We believe that, in some cases, the stresses are completely eliminated and this eliminates the need for an anchor.’

The team has already manufactured hitherto impossible geometries with ASLM using low-melt-temperature metals, which have limited uses and value. Now the scientists are aiming to replicate the process with metals that have a higher melt temperature, with a particular emphasis on making parts out of aluminium.

Hopkinson claimed that the process could be particularly relevant to the aerospace and automotive industries that already use eutectic system alloys.

The work being done by the Sheffield team has been backed with £184,729 in funding from the EPSRC.