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The changes in the material properties of water turbine blades are characterized an undesirable process, which could lead to the end of usable life or to the emergency conditions of this turbine. For this reason, it is important to determine of any material quality changes and continuously monitor them. Considering that, these essential parameters are showing the ability of material to resist the operational stress. It is necessary to choose rapid methods of the material testing which are without preparation of the samples (it is inadmissible to the functional blades) able to immediately monitor the state of the materials by nondestructive methods. Due to mechanical stress and operational wear, the losses and damage occur in the water turbine blades, as the result, it leads to the deformation changes. This article is focused on the methodology of determination mechanical properties of corrosion-resistant steel, which is used on a large scale for the production of hydraulic elements and especially blades of water turbines.

Pulsed plasma transferred arc surfacing is presently used in many industrial applications to make protective layers against corrosion, temperature exposition, and excessive wear. Increasing wear resistance is especially important in areas of industry where titanium alloys are used, such as aviation and cosmonautics, because the wear resistance of titanium alloys is often weak. One way to increase the wear resistance is to deposit or form a cermet with a titanium matrix (TMC) on the surface of the part. The present study deals with the fabrication and characterization of TMC based on B4C. TMC with B4C was formed by cofeeding Ti6Al4V and B4C powder into a melting pool. It has been found that the deposited, relatively thick layers have homogeneously dispersed B4C grains in the matrix. The deposits are metallurgically connected to the substrate - Ti6Al4V. The TMCs were investigated in terms of microstructure and chemical composition. Wear resistance was determined using the linear pin test.

Interactive thermochromic coatings based on Leuco dye are most commonly used in research for building cooling applications. The coatings developed by the authors are primarily aimed at industrial applications on metal substrates, mainly for safety reasons. Thanks to a higher transition temperature associated with a significant change in shade, they have the potential to prevent burns and can be used as an element of active protection in exposed areas. Interactive thermochromic materials with different base matrices and two dispersion methods have been monitored and tested over the long term to gain an overall impression of their behaviour and applicability. The monitoring of colour characteristics helps to understand the behaviour of the thermochromic pigment in different primer matrices. The values of L*, a*, and b* and the spectral curves measured by a spectrophotometer were compared. Colour differences between the cold and heated conditions were also evaluated. ΔE* values for acrylate polyol reached up to 39. For waterborne paint, they varied according to the method of dispersion—when using a saw tooth stirrer, ΔE* was 23, and when mixing with a rotor-stator device, up to 56. Similarly, for the polyurethane matrix: ΔE* went up to 39 for stirring with a saw tooth stirrer while ΔE* was 64 for the rotor-stator. From the measurement of the behaviour of the coatings during temperature exposure, it can be concluded that most of the samples show a decrease in the transition temperature. Monitoring the behaviour of coatings during cooling is important for choosing a suitable base matrix that will ensure the long-term functionality of the coating and declare the temperature range of its use for safety applications.

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