Scientists at the Fraunhofer Institute in Bremen, Germany, are developing a manufacturing technique to allow electric sensors, actuators and components to be integrated into light metals while they are being cast. This would create ‘intelligent’ parts that could monitor components’ stability or track their movements.

Working as part of the InGuss project, researchers have created insulating ceramic and polymer materials to house the electronic components and protect them from the high temperatures of casting, which can rise above 700ºC.

The casting process used is standard, with a few adjustments, says Franz-Josef Wöstmann of Fraunhofer’s Institute for Manufacturing Technology and Applied Materials Research. ‘For our test we used a cold chamber high pressure direct casting facility with a closing force of up to 660t, but it is also possible to use facilities with higher closing forces.

‘The problems we have worked on are reducing heat induction in the electronic components, and guaranteeing the position of the component in the casting part.’

Wöstmann could not go into details on the exact changes made to the casting process or the composition of the insulating materials, as the project is yet to be completed. However, he did say the technique has been trialled on aluminium, magnesium and zinc, in which components such as piezoceramic sensors, radio-frequency identification (RFID) tags, thermocouples, light emitting diodes and batteries were successfully implanted.

At the Hannover Messe technology conference held in Germany in April, the group displayed an intelligent bicycle pedal crank that incorporates two piezo-sensors. The sensors measure the forces of the pedalling crank, and show the rider how ‘evenly’ he is pedalling (meaning how efficiently he is making his gear changes) through wirelessly transmitting this information to a PC.

Other applications for this technology could include wireless part detection, tracking and tracing using RFID, and health monitoring, says Wöstmann.

Geoff Scamans of Innoval Technology Ltd, Banbury, UK, a consultancy for manufacturers and end-users of aluminium, says the biggest concern with integrating electronics into light metals is what happens when the part is remelted. ‘With the [EU] End of Life Vehicles Directive, people in casting are worried about anything that interferes with sending scrap back. If there’s anything in the metals that has a residual impurity, that would be a problem.’

He is interested in seeing the results of the project, as he is not convinced applying a sensor to the inside of a metal, rather than to its surface, adds any value.

The InGuss team aims to publish its final report in October.

 

Author : Meagan EllisMaterials World Magazine, 01 Sep 2008