Prohlížení Acta Polytechnica CTU Proceedings. 2020, vol. 27 dle názvu

Zobrazují se záznamy 1-20 z 31

    • APPLICATION OF STEEL FIBRES IN ALKALI-ACTIVATED MORTARS 

      Autor: Hüsken, Götz; Wagner, Lars-Christian; Gluth, Gregor J. G.; Pirskawetz, Stephan; Kühne, Hans-Carsten
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Alkali-activated materials are ideal for the repair of concrete structures in harsh environmental conditions due to their high durability in chemically aggressive environments. However, slag-based mortars, in particular, ...

    • BENEFITS OF USE OF ACOUSTIC EMISSION IN SCRATCH TESTING 

      Autor: Václavek, Lukáš; Tomáštík, Jan; Chmelíčková, Hana; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Scratch test is regularly used for assessment of cohesive and adhesive strength of thin films and coatings. By default, its evaluation is based on analysis of depth-load-time record and microscopic observation of residual ...

    • CHARACTERIZATION OF TITANIUM LASER WELDS 

      Autor: Chmelíčková, Hana; Hiklová, Helena; Václavek, Lukáš; Tomáštík, Jan; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Butt welding of commercially pure titanium Grade 1 and Ti6Al4V alloy sheets using a pulsed Nd:YAG laser KLS 246 - 102 LASAG were carried out to determine optimal values of pulse energy and pulse length to create completely ...

    • COMPARISON OF Mo COATING DEPOSITED BY TWAS AND APS SinplexPro THERMAL SPRAY TECHNIQUES 

      Autor: Houdková, Šárka; Antoš, Jakub; Šulcová, Petra; Lencová, Kateřina; Hajšman, Jan; Burdová, Karolína; Duliškovic, Josef
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The wear resistant Mo coatings were deposited using SmartArc Electric Arc Wire Spray System and advanced SinplexPro high throughput atmospheric plasma spray gun. The coatings were analyzed in terms of microstructure, ...

    • COMPARISON OF TWO TECHNIQUES FOR EVALUATING SPHERICAL INDENTATION DATA 

      Autor: Materna, Aleš; Haušild, Petr; Ondráček, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Flow curves of 15Kh2MFA, Sv 08Kh19N10G2B and 08Kh18N10T steels used for fabrication of WWER-440 nuclear reactor pressure vessel and core internals were obtained using the automated ball indentation (ABI) test technique and ...

    • COMPRESSION OF ECAPED TITANIUM MICRO-PILLARS FOR TWO PRINCIPAL ORIENTATIONS 

      Autor: Vokoun, David; Maňák, Jan; Tesař, Karel; Habr, Stanislav
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The thermomechanical processing by equal-channel angular pressing (ECAP) is used for certain metals and alloys in order to make their structure fine and to increase material strength. In the previous study done at our ...

    • DISTRIBUTION OF HYDRATION PRODUCTS IN THE MICROSTRUCTURE OF CEMENT PASTES 

      Autor: Hlobil, Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This case study focuses on the quantification of the amorphous hydrate distribution in the microstructure of hardened cement paste. Microtomographic scans of the hardenend cement paste were thresholded based on histogram ...

    • DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS 

      Autor: Daniel, Josef; Grossman, Jan; Buršíková, Vilma; Zábranský, Lukáš; Souček, Pavel; Mirzaei, Saeed; Vašina, Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to ...

    • ELECTRON RADIATION EFFECT ON INDENTATION CREEP OF CONSTRUCTION POLYMERS 

      Autor: Ovsík, Martin; Staněk, Michal; Dočkal, Adam; Fluxa, Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Cross-linking is a process in which polymer chains are associated through chemical bonds. Radiation, which penetrated through specimens and reacted with the cross-linking agent, gradually formed cross-linking (3D net), ...

    • ESTIMATION OF ANISOTROPIC ELASTIC PROPERTIES OF CARBON FIBERS USING NANOINDENTATION 

      Autor: Guruprasad, Thimmappa Shetty; Keryvin, Vincent; Bourmaud, Alain
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Understanding the mechanical behavior of carbon fiber reinforced polymers requires knowledge on the deformation behavior of carbon fibers, they are highly anisotropic and heterogeneous. Nanoindentation is an efficient ...

    • EVALUATION OF INTERNAL COHESION OF MULTIPHASE PLASMA-SPRAYED COATINGS BY CAVITATION TEST: FEASIBILITY STUDY 

      Autor: Mušálek, Radek; Nardozza, Emanuele; Tesař, Tomáš; Medřický, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Mechanical characterization of plasma-sprayed coatings at microscopic level represents a major challenge due to the presence of numerous inherent microstructural features such as cracks, pores, or splat boundaries, which ...

    • FRACTURE BEHAVIOR OF FeAlSi INTERMETALLICS 

      Autor: Čech, Jaroslav; Haušild, Petr; Karlík, Miroslav; Nová, Kateřina; Průša, Filip; Novák, Pavel; Kopeček, Jaromír
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The study is devoted to the intermetallic alloy FeAl20Si20 (wt.%) with the potential applications in high temperature aggressive environments. The samples of the same chemical composition were prepared by spark plasma ...

    • HARDNESS OF HYBRID PVD-PECVD W-C:H COATINGS VS. SUBSTRATE TYPE 

      Autor: Lofaj, František; Kabátová, Margita
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The effects of substrate on the measurement of hardness (and indentation modulus) - penetration depth profiles were investigated on hybrid PVD-PECVD W-C:H coatings made with the additions of C2H2 or CH4 using High Power ...

    • HARDNESS OF NITRIDED LAYERS TREATED BY PLASMA NITRIDING 

      Autor: Joska, Zdeněk; Pokorný, Zdeněk; Kadlec, Jaromír; Studený, Zbyněk; Svoboda, Emil
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Stainless steels, particularly the austenitic stainless grades are widely used in many industries due to good corrosion resistance, but very poor mechanical properties as surface hardness and wear resistance limit its ...

    • HOT HARDNESS MEASUREMENTS ON MATERIALS UP TO 600 °C DURING THE FIRST HOUR OF USING 

      Autor: Passilly, Bruno; Molenda, Lara
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In the aeronautical field, materials are used in severe environmental conditions (temperature, atmosphere, exposure time ...), particularly for engine applications. In order to characterize the use of these materials in ...

    • INDENTATION SIZE EFFECT IN HIGH PRESSURE TORSION PROCESSED HIGH ENTROPY ALLOY 

      Autor: Haušild, Petr; Čížek, Jakub; Čech, Jaroslav; Zýka, Jiří; Kim, Hyoung Seop
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      High entropy alloy HfNbTaTiZr in as cast conditions and after high pressure torsion straining was characterized by nanoindentation. The length-scale dependent material response (indentation size effect) was characterized ...

    • INFLUENCING THE INDENTATION CURVES BY THE BLUNTNESS OF THE BERKOVICH INDENTER AT THE FEM MODELLING 

      Autor: Kovář, Jaroslav; Fuis, Vladimír; Tomáštík, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The influence of the Berkovich indenter bluntness on the indentation curves at nanoindentation test of fused silica is determined by the FEM (finite element method) in this paper. The Berkovich indenter, which is mostly ...

    • LASER-INDUCED SURFACE ACOUSTIC WAVES FOR THIN FILM CHARACTERIZATION 

      Autor: Kudělka, Radim; Václavek, Lukáš; Tomáštík, Jan; Malecová, Sabina; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Knowledge of mechanical properties of thin films is essential for most of their applications. However, their determination can be problematic for very thin films. LAW (Laser-induced acoustic waves) is a combined acousto-optic ...

    • LOCAL MECHANICAL PROPERTIES OF ATMOSPHERIC SPRAYED MOLYBDENUM COATINGS DEPOSITED WITH CASCADED PLASMA TORCH 

      Autor: Antoš, Jakub; Šulcová, Petra; Lencová, Kateřina; Houdková, Šárka; Duliškovic, Josef; Hajšman, Jan; Burdová, Karolína; Račický, Antonín
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Increasing interest for industrial use of thermally sprayed coatings leads to development in most thermal spraying technologies, including atmospheric plasma spraying (APS). The latest cascaded torch SinplexPro from Oerlikon ...

    • LOCAL NANO-MECHANICAL PROPERTIES OF CROSS-LINKED POLYBUTYLENE 

      Autor: Ovsík, Martin; Staněk, Michal; Dočkal, Adam; Fluxa, Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Cross-linking is a process in which polymer chains are associated through chemical bonds. The cross-linking level can be adjusted by the irradiation dosage and often by means of a cross-linking booster. The polymer additional ...