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This paper presents a short overview of the high flexibility and potential of inductively coupled thermal plasmas for the synthesis of nanoparticles and especially high refractory carbide nanopowders. The high energy and temperature of theses plasmas enable the evaporation of all materials allowing the use of solid precursors that are cheap and commercially available. By controlling the temperature history of each particle, the growth mechanisms can be stopped at the requested particle size. Therefore in‐situ monitoring and process modelling are proved to be powerful tools.

The process parameters of an inductively coupled thermal plasma used for nanopowder synthesis are experimentally investigated using various plasma diagnostics and in situ powder monitoring methods. An enthalpy probe technique is applied to characterize the plasma properties under particle-free conditions. The nanoparticle synthesis from microscale alumina precursors is monitored in situ by optical emission spectroscopy and laser light extinction measurements to investigate the powder evaporation. The synthesized powders are collected in a sampling unit and characterized ex situ by particle size analysis as well as by electron microscopy. At low flow rates of the torch central gas, higher plasma enthalpy, a laminar powder flow and increased evaporation of the precursor have been observed. A precursor-and an energy-deficient regime related to the precursor feed rate and plasma enthalpy are found from the emission line intensities of aluminium metal vapour. The number fraction of plasma-treated precursors, which is an important process parameter, is calculated from the precursor number density obtained from laser extinction measurements.

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In this paper, experiments for determining the adhesion properties have been performed using two test methods; tensile adhesive test which is widely used in industry and interfacial indentation test still under development in research laboratories. Therefore, only few experimental data on the accuracy of the methods and on the potential in an industrial context are available. For that reason, dissimilar coating-substrate combinations covering different ranges of type of thermal spray coating-substrate systems were tested. Ceramic (Al 2 O 3 ) and metallic (80Ni-20Cr) coatings were deposited by flame spraying system with two different thicknesses on titanium alloy and steel substrates exhibiting each two distinct roughness levels. The distinguished coating properties include the interfacial toughness and adhesive strength. The impacts of interfacial roughness and the thickness of the coating on the adhesion were conducted, and some adhesion tendency was also observed. Typical bond strength values measured were from 40 up to 100 MPa, and the interfacial toughness obtained from 1 to 4 MPa m 0?5 . The correlation of tensile adhesive strength and interfacial toughness has been discussed.