Papers by Keyword: Thermo-Mechanical Properties

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Authors: Bruno Viana, J. Petit, R. Gaumé, Philippe Goldner, F. Druon, F. Balembois, P. Georges
Abstract: The emergence of new laser crystals has allowed progress in ultrashort-pulsed laser technology and high power lasers. Extensive researches on new Yb3+ doped crystals enable development of all-solid-state femtosecond lasers. Thermo-mechanical properties should be taken into account. The review of the state of the art on the Yb doped laser material for high power and ultrafast pulses generation is presented.
Authors: Jan Zatloukal, Jindřich Fornůsek, Petr Bezdička, Martin Gajdoš
Abstract: The civil structures of nuclear plants need to meet the most strict criteria in terms of safety and reliability not only during their design and construction, but during the duration of their life cycle. In addition, during the life-cycle of nuclear plant higher safety demands than the ones at the time of plant design may appear and the plant needs to prove meeting of such requirements. Validation of thermo-mechanical properties was required for the concrete structure of the containment building of Bohunice NPP in Slovakia. Identification of thermo-mechanical parameters of the material used in the containment structure was necessary to perform said analysis and detailed investigation on the concrete composition was performed. This paper describes the information that can be obtained using state-of-the art analytical methods – X-ray diffraction (XRD), X-ray fluorescence (XRF) and thermic analysis (TG/DTA).
Authors: Phuc Nguyen, Andrei G. Kotousov, Sook Ying Ho, Stuart Wildy
Abstract: Thermal Barrier Coatings have existed for over 40 years, and with in the last 15 years their use in industrial applications has dramatically increased. Thermal Barrier Coatings (TBCs) are currently used in gas turbines, diesel engines, throughout aerospace and nuclear power industries. The purpose of TBC is to reduce temperature and thermal stresses, and, as a result, increase the reliability and life of load-bearing components subjected to high temperature or temperature flux. However, TBCs often fail under thermal cyclic loading with reliability still being the major issue impeding their wide-spread applications. The focus of this work is on experimental investigations of zirconia/nickel graded TBC system, subject to thermal shock loading. The graded TBC systems were fabricated utilising a recently developed slurry spray manufacturing technique. This is a robust technique, and is able to cover large and curved surfaces at low cost, and provides many advantages in comparison with its alternatives. This paper describes the developed technique and presents selected results of thermo-mechanical and fracture testing of the TBCs including graded coatings fabricated using this new technique.
Authors: Gancho Genchev, Ossama Dreibati, Ralf Ossenbrink, Nikolay Doynov, Vesselin Michailov
Abstract: The paper presents a numerical and experimental approach for the quantification of the thermo-mechanical properties in multi-pass welds heat affected zone (HAZ) of low alloy steel S355J2+N. First, the characteristic temperature cycles for multi-pass welds were identified by FE temperature field simulations of welding. Based on the identified temperature cycles, the microstructure in the HAZ has been physically simulated with the simulation and testing system Gleeble 3500 to investigate the influence of multi thermal exposure on the thermo-mechanical properties. Thus, the thermo-mechanical material properties including thermal strain and temperature dependent stress strain behaviour as function of peak temperatures and cooling rates have been determined. These material properties were used to calibrate a developed model for numerical prediction of the material properties of multi-pass weld HAZ.
Authors: José San Juan, P.P. Rodríguez, M.L. Nó, Oscar A. Ruano
Authors: Xin Hong Liu, En Xia Xu, Chao Jie Zhou
Abstract: The composite specimens have been prepared using fused corundum, silicon and bauxite-based β-SiAlON powder as starting materials. The physical properties, high temperature modulus of rupture (HMOR), thermal shock resistance (TSR), phase composition and microstructure of the specimens after firing at 1500°C have been studied. The results show: (1) Al2O3-SiC-SiAlON composites are sintered well at 1500°C. (2) HMOR and TSR of the specimens increase with increase of Si content, high temperature properties are further increased with appropriate β-SiAlON addition. (3) The in-situ formed SiC and O’-SiAlON fill in the interstices of corundum skeleton structure, forming interlocking network structure, thus creating strengthening and toughening effects.
Authors: Hisaaki Tobushi, K. Okumura, M. Endo, S. Hayashi
Authors: Yu Jun Cai, Felix Stephanus Halim, Guo He Li, Yu Guang Wang
Abstract: Hot stamping is a process which simultaneously forms and quenches the hot blanks at the austenization temperature (900-1200 °C) to produce full martensitic Ultra High Strength (UHS) steel structure. Automobile manufacturers use hot stamping to produce many car frame components which can decrease the total weight of the car and increase the car safety. The aim of this paper is to simulate the thermo-mechanical process of the hot stamping which consists of FEA simulations by using Abaqus/Explicit. The process includes too steps: heating of the blank to 900°C, and simultaneous punching and quenching process to increase the tensile strength of the material. The objectives of the FEA simulation are to obtain thermo-mechanical properties of the material and to predict strength of the steel as the product of hot stamping. The results of this simulation will be the values of maximum Von Mises stress and nodal temperature of the blank, the punch reaction force, and also the prediction of the yield strength and tensile strength of the material which will be compared to the yield strength and tensile strength of the available steel alloy data.
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