Abstract No.:
7302

 Title:
Assessment of high entropy alloys as thermally sprayed heating elements

 Authors:
Andreas Schacht* / RWTH Aachen University, Germany
Kirsten Bobzin / Surface Engineering Institute, Germany
Hendrik Heinemann/ Surface Engineering Insitute, Germany

 Abstract:
An efficient temperature control on tool surfaces is essential in processes like injection moulding or die casting. A thermally sprayed heating coating could combine dynamic heating properties with a small assembly space as it is sprayed directly onto the cavity surface. With their intrinsically high electrical resistivity and low thermal expansion as compared with traditional alloys, High Entropy Alloys (HEA) show promising properties for the use as heating elements. Thus, the well-studied Al0.5CrCoNiFe HEA was used as a starting material for additional alloying with Zr and Si to force further lattice distortion in the solid solution. HEAs of differing compositions were melted and characterized. In the process, the potential of HEAs was assessed by characterizing their phase composition, thermal stability and electrical resistivity. The characterized HEAs show a solid solution mainly consisting of fcc and bcc structure. Moreover, the composition Al0.5CrCoFeNiZr0.2Si0.2 was determined as stable after heat treatment at 600 °C for 324 h. In addition, the electrical resistivity was raised by up to 30 % relative to the starting material. As a result, a hitherto unknown HEA composition was detected to possess superior properties to traditional alloys for the application as heating coating.

<= go back