TY - JOUR A1 - Frunzaverde, Doina A1 - Marginean, Gabriela A1 - Ciubotariu, Costel-Relu T1 - Corrosion and Cavitation Performance of Flame-Sprayed NiCrBSi Composite Coatings Reinforced with Hard Particles JF - Crystals (Special Issue Modern Technologies in the Manufacturing of Metal Matrix Composites) N2 - To enhance the operational life of hydraulic machinery, protective coatings against wear, particularly cavitation erosion, and corrosion might be applied on the surfaces of components. The experiments conducted in this study aimed to assess the suitability of 80/20 NiCrBSi/WC-Co composite coatings for this purpose. A coating of NiCrBSi self-fluxing alloy, which served as the reference material, was deposited alongside a NiCrBSi coating reinforced with 20% WC-Co, both applied by flame spraying onto X3CrNiMo13-4 substrates, the martensitic stainless steel type frequently utilized in turbine blade manufacturing. The improved density of the coatings and adhesion to the substrate was achieved by remelting with an oxyacetylene flame. The cavitation and corrosion performance of both the reference and composite coating were evaluated through cavitation tests and electrochemical measurements conducted in the laboratory. The results demonstrate that the addition of 20% WC-Co significantly enhances the cavitation resistance of the composite material, as evidenced by the reduction to 3.76 times of the cumulative erosion (CE), while the stabilization rate remained at half the value observed for the reference self-fluxing alloy coating. Conversely, the addition of WC-Co into the NiCrBSi coating resulted in a slight decrease in the corrosion resistance of the self-fluxing alloy. Nevertheless, the corrosion rate of the composite coating (124.80 µm/year) did not significantly exceed the upper limit for excellent corrosion resistance (100 µm/year). KW - cavitation resistance KW - corrosion resistance KW - coatings KW - hydraulic machinery KW - self-fluxing alloys KW - NiCrBSi KW - WC-12Co KW - NiCrBSi/WC-Co composites Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1010-opus4-47740 SN - 2073-4352 VL - 2024 IS - 14 (12) SP - 1 EP - 12 PB - MDPI ER - TY - JOUR A1 - Cojocaru, Vasile A1 - Turiac, Raul-Rusalin A1 - Frunzaverde, Doina A1 - Trisca, Gelu A1 - Bacescu, Nicoleta A1 - Marginean, Gabriela T1 - Effect of the Printing Scenario on the Dimensional Accuracy and the Tensile Strength of Different Colored PLA Specimens Produced by Fused Deposition Modeling JF - Applied Sciences N2 - Dimensional accuracy and mechanical properties of components printed by fused deposition modeling (FDM) are influenced by several process parameters. In this paper, the authors targeted the effect of the printing scenario and the PLA (polylactic acid) color on parts’ quality. Three scenarios were analyzed: individually printing, simultaneously printing of three, respective five specimens of natural (transparent), red, grey, and black PLA. The temperature variations of successive deposited layers were recorded for the black PLA. The dimensional accuracy of tensile specimens was evaluated, tensile tests were performed, and the results were correlated with the mesostructure of the prints. The effect of the independent variables on the measured parameters was analyzed by ANOVA. The experiments revealed differences for the same printing scenario regarding cross-section area (up to 5.71%) and tensile strength (up to 10.45%) determined by the material color. The number of specimens printed simultaneously and the position of the pecimens on the build plate were found to influence too, but less than the color. Thus, increasing from one to five the number of specimens printed at a time altered both the dimensional accuracy (up to 3.93% increase of the cross-section area) and the tensile strength (up to 3.63% reduction). KW - fused deposition modeling (FDM) KW - polylactic acid (PLA) KW - printing scenario KW - filament color KW - dimensional accuracy KW - tensile strength (UTS) Y1 - 2024 U6 - https://doi.org/10.3390/app14177642 VL - 14 (2024) IS - 17, Artikel 7642 ER -