Quasicrystalline materials offer outstanding properties: High thermal stability in mechanical behaviour combined with special thermal and electrical conductivity as well as excellent tribological performance. High hardness is accompanied by heavy brittleness - an undesired property when looking for possible applications. A reduction of brittleness can be achieved by embedding quasicrystalline phases into a more ductile material to form a metal-matrix-composite material keeping some quasicrystalline properties. For thermal spraying blended, agglomerated, chemical encased or attrition milled powders as well as filled wires are processable to form such a metal-matrix-composite coating. The research work included spray trials using material-input prepared by the methods described. These different inputs have been processed in different compositions each. Spray trials have been processed by following techniques: Arc-wire-spraying, APS-spraying, wire-flame-spraying and HVOF-spraying. This paper gives an overview about HVOF-sprayed coatings with blended powders. On the one hand investigation were focused on metallurgical analysis for proving the existence of quasicrystal contents as well as determining adherence and embedding behaviour of the matrix-phase. On the other hand tests were centred onto the evaluation of the sliding-wear-behaviour in respect of interdependencies to the coatings composition and microstructure.

Quasicrystalline phases improve many alloy properties such as thermomechanical stability, thermal and electrical conductivity, and tribological performance. High hardness, however, is accompanied by brittleness, an undesired property in many applications. Reduced brittleness can be achieved by embedding quasicrystalline phases in a more ductile material, forming a metal-matrix composite that retains some quasicrystalline properties. This study evaluates thermally sprayed coatings made from different compositions of such composites. The coatings assessed were produced by arc-wire, HVOF, and atmospheric plasma spraying using various forms of feed material, including blended, agglomerated, chemical encased, and attrition-milled powders and filled wires. The investigation involved metallurgical analysis, proving the existence of quasicrystal content and assessing the matrix phase, and tests showing how sliding wear is influenced by the composition of quasicrystalline phases.