Key Technologies

 

Plasma spraying – method of preparation of protective layers or free-standing shapes. Deposited material, in the form of powder or liquid, is injected into plasma jet generated by a plasma torch, where it is melted and accelerated. After the impact of numerous droplets onto the component surface and their solidification, lamellar plasma sprayed coating is formed.

 

WSP-H – so called hybrid WSP (Water Stabilized Plasma) torch. In the WSP-H torch, plasma is formed by electric arc from water steam and gas (argon). This approach combines benefits of gas stabilization (non-consumable tungsten cathode) and water stabilization (high enthalpy, feed rates up to tens of kg per hour). WSP-based plasma torches are most suitable for spraying of large areas or deposition of thick coatings, preparation of free-standing parts and materials processing (including e.g. powder spheroidization). Both dry powders as well as liquids (suspensions and solutions) may be used as feedstock. The latest generation of WSP-H torches was developed in cooperation of our institute and ProjectSoft HK a.s. company. Typical materials sprayed in our laboratory include oxides (alumina, chromia, zirconia, titania, etc.), tungsten, silicates, carbides, minerals, and many others. We can also perform plasma spraying with the previous generation of WSP torch with graphite cathode.

 

For further details visit www.wsp-h.com.

Cold spray (CS) or Cold kinetic spraying is a highly effective method for depositing pure metals and metallic alloys. Unlike its high-temperature thermal spray counterparts, CS does not melt the input powder materials. Instead, coatings and deposits are formed through kinetic energy. This approach eliminates common drawbacks of thermal spraying, including oxidation, phase changes, and selective evaporation, resulting in superior coating microstructure and properties. The deposited materials are highly homogeneous, pore-free, and exhibit excellent adhesion, cohesion, strength, and hardness. The method also offers exceptional throughputs of up to 80 kg/h with minimal material losses, and the deposits are easily machinable. As such, CS has been recently utilized also for both repairing damaged components and as an additive manufacturing (AM) process. Here, CS offers numerous advantages over fusion-based AM routes: the method allows printing of virtually unlimited component size, does not require an environmental chamber, produces no toxic waste, and poses no issues with reflective metals. Furthermore, it can deposit blends of metals with significantly different melting points and has a very low thermal input and heat-affected zone.

Spark Plasma Sintering (SPS), also called Field Assisted Sintering Technique (FAST) or Pulsed Electric Current Sintering (PECS), is a technology allowing fast compaction of both metallic and non-metallic powders. The powder is pressed in a die between two punches and heated by Joule heat generated by applied electric current. High heating rates and short sintering times allow for example elimination of undesirable grain growth during preparation of nanomaterials. Composite materials with tailored microstructure may be easily prepared by combination of two or more different powders.