Research Topics

The interactions of hot plasma with components of the first wall in fusion reactors (e.g., tokamaks) often lead to undesirable microstructural changes that affect their functional properties and long-term durability. As no conventional material is suitable for these conditions, we focus on the development of special alloys and composite structures that combine the functional advantages of their individual constituents. Our research in fusion-relevant materials includes primarily tungsten-based materials and their alloys, as well as low-Z materials in the form of surface coatings applied by various thermal spraying techniques or as bulk materials fabricated by spark plasma sintering (SPS).

 

Protective or functional surface coatings are essential in many industrial sectors. They are applied to enhance properties such as wear resistance, corrosion resistance, thermal or electrical conductivity and insulation. We focus on thick surface coatings preparation using various thermal spray techniques, including plasma spraying and cold spray. Our lab operates two plasma spray systems and flame spray as complementary method. Our Laboratory of Plasma Technologies (LPT)  in Prague–Letňany utilizes a world‑unique hybrid water/argon-stabilized plasma torch (WSP-H). We also conduct R&D using a radiofrequency inductively coupled plasma torch (RF-ICP) in a controlled atmosphere. In addition to conventional powder plasma spraying, we explore suspension and solution plasma spraying, as well as hybrid plasma spraying where powder and liquid feedstocks are deposited simultaneously. Our specialties include functionally graded materials, layered composites, and free-standing ceramic coatings (shells). Commonly deposited materials include oxide ceramics (Al₂O₃, TiO₂, ZrO₂, YSZ), natural minerals (silicates, garnets), and special materials (carbides, titanates, aluminides). In the field of cold spray, we prepare thick coatings from pure metals (e.g., Al, Cu, Fe, Nb, Ni, Ta, Ti, W, Zn, Zr) and their alloys.

 

Our dedicated ColdSprayPrague laboratory specializes in the development and deposition of pure metals, alloys, and their composites with ceramics. Unlike conventional thermal spray techniques, cold spray enables deposition without oxidation or thermal degradation. It operates in open atmosphere, eliminating the need for a deposition chamber and allowing handling of large components. This method is increasingly used not only for thick coatings, but also for economical and rapid repair of damaged mechanical parts. Additionally, cold spray enables additive manufacturing (Cold Spray Additive Manufacturing, CSAM).

 

To produce bulk materials, we use an advanced method of powder consolidation known as spark plasma sintering (SPS) or field-assisted sintering technique (FAST). This process combines high pressure with pulsed electrical current, significantly reducing sintering time compared to the conventional methods. It is especially suitable for the fabrication of ultra-fine-grained materials and complex composites. We are also actively developing its advanced variant – flash sintering or ultrafast high-temperature sintering (UHS).

 

Using techniques such as mechanical alloying, powder heat treatment in controlled atmosphere, and plasma spheroidization, we produce tailored powder precursors for further use in thermal spraying, additive manufacturing, or sintering. Our research includes alloy preparation through high-energy powder milling, powder spheroidization and homogenization via plasma treatment, and controlled microstructural modification through heat treatment.

 

Our department is equipped with a comprehensive set of tools for complex analysis of materials microstructure, properties, and failure mechanisms. We focus on internal structural characterization, chemical and phase analysis, as well as mechanical (strength, hardness, wear resistance, internal stress), thermal (stability, oxidation, conductivity), and physical properties (surface characteristics, dielectric behavior, dielectric strength, photocatalysis). For failure analysis, we combine methods of nonlinear fracture mechanics with fractography and conduct fatigue resistance and fracture toughness testing. We also collaborate with our partners on the development of specialized testing methodologies.

 

We develop materials for specific advanced applications. In the field of dielectric materials, we study behavior under variable AC frequencies and temperature conditions, and analyze how microstructure, crystallinity, and purity affect materials behavior. Our focus includes CaTiO₃, BaTiO₃, MgTiO₃, PbTiO₃–ZrTiO₃, Al₂O₃–TiO₂, and various natural and synthetic silicates. In photocatalytic materials, we investigate plasma-sprayed titanium dioxide-based coatings with dopants engineered to tailor the bandgap. We are also developing materials for fuel cells and high-temperature electrolysis (SOFC/SOEC – solid oxide fuel/electrolyzer cells), where plasma spraying enables scalable deposition even on complex-shaped surfaces.