PSI - Issue 13

ScienceDirect Available online at www.sciencedirect.com Available online at www.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Structural Integrity 13 (2018) 1834–1839 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2018) 000 – 000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. ECF22 - Loading and Environmental effects on Structural Integrity The corrosion resistance in artificial saliva of titanium and Ti-13Nb 13Zr alloy processed by high pressure torsion Dragana Barjaktarević 1* , Jelena Bajat 1 , Ivana Cvijović - Alagić 2 , Ivana Dimić 1 , Anton Hohenwarter 3 ,Veljko Đokić 1 and Marko Rakin 1 1 Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia 2 Institute of Nuclear Sciences ‘‘Vinča’’, University of Belgrade, Belgrade, Serbia 3 Department of Materials Physics, Montanuniversität Leoben, Leoben, Austria Abstract In order to optimize and enhance the implant material properties, metallic materials may be modified by severe plastic deformation (SPD) procedures. One of the most attracting SPD methods is high-pressure torsion (HPT), which is method where deformation is obtained mainly by simple shear. In the present study ultrafine-grained titanium (UFG cpTi) and ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy were obtained by high pressure torsion (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. In order to analyse microstructure of materials before and after HPT process, scanning electron microscope (SEM) was used. The aim of this study was to determine the corrosion resistance of titanium and its alloy after HPT process. Electrochemical measurements were performed in artificial saliva with a pH value of 5.5 at 37°C, in order to simulate the oral environment. The materials were analysed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. All examined materials showed good corrosion resistance, but results indicate that HPT process can improves corrosion resistance. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: corrosion resistance, biomaterials, high pressure torsion, titanium alloy 1. Introduction The good corrosion resistance is important properties for metallic biomaterials, because the ion release from the implant to the surroundi g tissue may give rise t probl ms in the human body [1]. Titanium and its alloy show very good corrosion resistance in many media due to the formation of passive TiO 2 thin film on its surface [2]. The cpTi is one of the best metallic biomaterial for dental application due to corrosion resistance, but it does not have high enough strength for more applications. The mechanical properties of metallic biomaterials may be improved by severe plastic deformation (SPD) procedures, which lead to the formation of ultra fine microstructures. © 2018 The Authors. P blished by Elsevier B.V. Peer-review und responsibility of the ECF22 organiz rs. ECF22 - Loading and Environmental effects on Structural Integrity The corrosion resistance in artificial saliva of titanium and Ti-13Nb 13Zr alloy processed by high pr ss e torsion Dragana Barjaktarević 1* , Jelena Bajat 1 , Ivana Cvijović - Alagić 2 , Ivana Dimić 1 , Anton Hohenwarter 3 ,Veljko Đokić 1 and Marko Rakin 1 1 Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia 2 Institute of Nuclear Scie ces ‘‘Vinča’’ 3 Department of Mater als Physics, Monta universität L oben, Leoben, Aust ia Abstract In order to optimize and enhance the implant material properties, metallic materials may be modified by severe plastic deformation (SPD) pr cedures. One of t e most attracti g SPD meth ds is high-pressure o sion (HPT), which is method where deformation is obtained mainly by simple sh ar. In the present study ultrafine-gra ned titanium (UFG cpTi) and ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy were obtained by high pressur torsion (HPT) under a pressure of 4.1 GPa with a rotational sp ed of 0.2 rpm up to 5 rotations at room temp rature. In order to analyse microstructure of mat rials before and after HPT proc ss, scanning elec ron microscope (SEM) was used. The aim of this study was to determine the corrosion r sistance of titanium and it lloy aft r HPT proce s. El ctrochemical m asurements were performed in artificial saliva with a pH value of 5.5 at 37°C, in order to simulate the oral environment. The aterials wer analysed by lectrochemical mped nce spectroscopy (EIS) and potentiodynamic polarization. All xamined materials showed good corrosion resistance, but results indicat that HPT process can improves corrosion resistance. © 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. Keywords: corrosion resistance, biomaterials, high pressure torsion, titanium alloy 1. Introdu tion The good corrosion resistance is important properties for metallic biomaterials, because the ion release from the implant to the s rr unding tissue may give rise to problems in the human body [1]. Titanium and its alloy show very good corrosion resistance n many media due to the formation of passive TiO 2 thin film on its surface [2]. The cpTi is one of the best metallic biomaterial for dental application due to corrosion resistance, but it does not have high enough strength for more applications. The mechanical properties of metallic biomaterials may be improved by severe plastic deformation (SPD) procedures, which lead to the formation of ultra fine icrostructures. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Dragana R. Barjaktarevi ć . Tel.: +381-63-546-596. E-mail address: dbarjaktarevic@tmf.bg.ac.rs. * Dragana R. Barjaktarevi ć . Tel.: +381-63-546-596. E-m il address: db rj ktarevic@tmf.bg.ac.rs.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216© 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 2452-3216© 2018 The Authors. Published by Elsevier B.V. Peer review under responsibility of the ECF22 organizers.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

2452-3216  2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ECF22 organizers. 10.1016/j.prostr.2018.12.332