Development of tungsten-based functional gradient materials prepared using powder laser deposition
Project ID:WP08-09-MAT-WWALLOY
Provider:Euratom under European Fusion Development Agreement
Period:Nov 01, 2008 - Dec 31, 2011
Principal Investigator:Ing. Jiří Matějíček, PhD.
Co-investigatorsH. Boldyryeva

Aims of the project: Development of functional gradient materials for the transition from W to Eurofer steel, using laser deposition from powders. Previous experiments with laser deposition of W powders onto steel indicated the formation of dense, fully remelted W layer and the formation of intermediate composite layer W/steel. Development will consist of testing various deposition parameter combinations, compositional profiles and thermal conductivity of the processed layer. The properties will be compared to alternative technologies.

Progress/Results: (annual report for 2011) Two alternative processing techniques were pursued: hot pressing and plasma spraying with hybrid argon-water torch. Hot pressing from powders was used to form homogeneous stainless steel/tungsten composites as well as FGMs. Essentially full density composites with homogeneous distribution of the phases and good bonding were produced. Formation of Fe7W6 phase at the interface was found. Complex characterization of the structure, thermal and mechanical properties was performed. Extensive plasma spraying with hybrid torch and inert gas shrouding was performed, with separate optimization of spraying parameters for tungsten and steel. W/steel composites were produced at conditions chosen as optimal from the previous experiments.