This study focuses on the investigation of fine (~0.54 μm) tungsten carbide particles effect on structural and mechanical properties of laser cladded Inconel 625-WC composite. Three powder mixtures with different Inconel 625 – WC weight ratio (10, 20 and 30 weight % of WC) were prepared. Coatings were made using following process parameters: laser beam diameter ø ≈ 500 μm, powder feeder rotation speed – 7 m/min, scanning velocity – 10 m/min, laser power – 220 W changed to 320 W, distance between tracks – 1 mm changed to 0.8 mm. Microstructure and hardness were investigated. Coatings produced by laser cladding were crack and pore free, chemically and structurally homogenous. High cooling rate during cladding process resulted in fine microstructure of material. Hardness improved with addition of WC from 396.3 ±10.5 HV for pure Inconel 625, to 469.9 ±24.9 HV for 30 weight % of WC. Tungsten carbide dissolved in Inconel 625 which allowed formation of intergranular eutectic that contains TCP phases.

In this study, the laser metal deposition (LMD) of the Inconel 625–tungsten carbide (WC) metal matrix composite was investigated. The composite coating was deposited on Inconel 625 substrate by powder method. A powder mixture containing 10 wt% of WC (5 µm) was prepared by wet mixing with dextrin binder. Coating samples obtained by low-power LMD were pore- and crack-free. Ceramic reinforcement was distributed homogenously in the whole volume of the material. Topologically close-packed (TCP) phases were formed at grain boundaries between WC and Inconel 625 matrix as a result of partial dissolution of WC in a nickel-based alloy. Line analysis of the elements revealed very small interference of the coating in the substrate material when compared to conventional coating methods. The average Vickers hardness of the coating was about 25% higher than the hardness of pure Inconel 625 reference samples.

The study focuses on obtaining Inconel 625-NbC composites for high-temperature applications, e.g., jet engines, waste-to-energy combusting systems or gas engine turbines, and characterizing them in terms of their microstructure and hardness improvement. Synthesis was performed utilizing Spark Plasma Sintering (SPS) at 1150 °C under the load of 45 MPa in medium vacuum (under 10⁻³ MPa) for a total time of 60 min. Four sets of samples with different Inconel 625 to NbC weight ratios were prepared (5, 10, 20, and 30 wt.%), followed by a reference sample containing no ceramic reinforcement. Obtained materials were hot-rolled at 1150 °C with a 10% reduction step and later cut and polished to perform characterization utilizing scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) module and microhardness testing device equipped with Vickers indenter. Hardness was improved proportionally to NbC addition achieving an increase of up to 20% of reference values. Additional heat treatment was conducted on the hot-rolled samples at 1200 °C in an argon atmosphere to further observe the interaction between reinforcement and alloy. Their microstructure revealed the coarsening of precipitates within the metal matrix and partial reinforcement dissolution, which proved to be crucial to obtaining the highest quality composites with homogenous hardness improvement.

Energy harvesting from mechanical vibration of buildings is usually realized by the use of devices, in which the main element is a prismatic beam with a rectangular cross-section. The beam has been the subject of scientific research; it is usually constructed with a carrying substrate that does not have piezoelectric characteristics and from piezoelectric material. In contrast, this investigation sought to create a beam structure with a piezoelectric composite only. The entire beam structure was made of a prototype piezoelectric particulate composite. Based on courses of voltage obtained in laboratory experiments and known geometry of the specimens, a series of finite element method (FEM) simulations was performed, aiming to estimate the piezoelectric coefficient d₃₁ value at which the mentioned voltage could be achieved. In each specimen, sedimentation caused the formation of two distinct layers: top and bottom. The experiments revealed that the presented prototype piezoelectric particulate composite converts mechanical stress to electric energy in bending mode, which is used in energy harvesting from mechanical vibration. It is self-supporting and thus a carrying substrate is not required in the harvester structure.