scholarly journals Effect of secondary crystal orientations on the deformation anisotropy for nickel-based single-crystal plate with notch feature

2019 ◽  
Vol 54 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Yu Zhai ◽  
Muhammad Kashif Khan ◽  
José Correia ◽  
Abílio MP de Jesus ◽  
Zhiyong Huang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Deformation Process ◽  
Crystal Orientation ◽  
Turbine Blades ◽  
Von Mises Stress ◽  
Slip Systems ◽  
Nickel Based Superalloy ◽  
Crystal Orientations ◽  
Single Crystal Plate ◽  
Von Mises

The effects of the secondary crystal orientations on the nickel-based single-crystal superalloy turbine blades were investigated. The stress concentration features were used for investigation of the optimal secondary crystal orientation leading to the higher strength of the single-crystal turbine blades. The crystal plastic finite element method coupled with micromechanics constitutive model is applied to study the effect of secondary crystal orientation on plastic deformation and mechanical behavior around the cooling holes and notches with the primary (load) orientation fixed at [001] direction. For nickel-based superalloy plates with holes or notches, the secondary crystal orientation effect on the strength needs to be clarified at various load levels. The maximum von Mises stress in the single-crystal alloy varies significantly with variation in the secondary crystal orientations. It was found that only two slip systems dominate the deformation process of the material owing to their favorable orientation with loading. The secondary orientation of 45° was identified with lowest resolved shear stress in the dominating slip systems and potential of producing higher strength for single-crystal turbine blades.

IMPROVEMENT OF THE CHEMICAL COMPOSITION AND STRUCTURE OF CASTABLE NICKEL-BASED SUPERALLOY WITH LOW DENSITY. Part 2

2021 ◽  
pp. 3-15
Author(s):  
N.V. Petrushin ◽  
◽  
E.M. Visik ◽  
E.S. Elyutin ◽  
◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Turbine Blades ◽  
Experimental Studies ◽  
Single Crystal Structure ◽  
Term Strength ◽  
Nickel Based Superalloy ◽  
Heat Treated ◽  
Composition And Structure ◽  
Short Term Strength

Results of design and experimental studies of a nickel-based superalloy VZhL20 with a density of 8.04 g/cm3 for the manufacture of turbine blades with a columnar granular structure and a single-crystal structure are presented. It is shown that alloy VZHL20 with a single-crystal structure of the crystallographic orientation [001] in the heat-treated state possesses high phase stability, and enhanced short-term strength ( = 950 MPa, = 1130 MPa), and long-term strength ( = 340 MPa, = 185 MPa).

Two Methods of Studying Structure Perfection of Single Crystal Nickel-Based Superalloys

2013 ◽  
Vol 203-204 ◽  
pp. 177-180 ◽  
Author(s):  
Arkadiusz Onyszko ◽  
Jan Sieniawski ◽  
Włodzimierz Bogdanowicz ◽  
Hans Berger
Keyword(s):  
Single Crystal ◽  
Crystal Orientation ◽  
Turbine Blades ◽  
Vacuum Furnace ◽  
Aerospace Materials ◽  
X Ray ◽  
University Of Technology ◽  
Assembly Structure ◽  
Development Laboratory ◽  
Laue Method

The article presents the comparison of two methods: classical X-ray topography and the modern automatic X-ray OD-EFG diffractometer. Both methods were applied to study the crystal orientation of turbine blades of single crystal nickel-based superalloys. The solidification of a hollow assembly structure for 5 various blades was carried out by the Bridgman method at the Research and Development Laboratory for Aerospace Materials at Rzeszow University of Technology using an ALD Vacuum Technologies vacuum furnace. Ceramic moulds made of Al2O3 were used. The alloy temperature during casting into the mould amounted to 1550°C. The specimens for Laue method tests were cut out from the blades at withdrawal rates of 1, 2, 3, 4, and 5 mm/min.

scholarly journals Dendritic Structure Analysis of CMSX-4 Cored Turbine Blades Roots

2016 ◽  
Vol 61 (2) ◽  
pp. 1129-1134 ◽  
Author(s):  
J. Krawczyk
Keyword(s):  
Single Crystal ◽  
Cross Sections ◽  
Induction Furnace ◽  
Turbine Blades ◽  
Dendritic Structure ◽  
Root Structure ◽  
Sem Images ◽  
X Ray ◽  
Nickel Based Superalloy

Abstract The microstructure of as-cast cored turbine blades roots, made of the single-crystal CMSX-4 nickel-based superalloy was investigated. Analysed blades were obtained by directional solidification technique in the industrial ALD Bridgman induction furnace. The investigations of the microstructure of blades roots were performed using SEM and X-ray techniques including diffraction topography with the use of Auleytner method. Characteristic shapes of dendrites with various arrangement were observed on the SEM images taken from the cross-sections, made transversely to the main blades axis. The differences in quality of the structure in particular areas of blades roots were revealed. Based on the results, the influence of cooling bores on blades root structure was analysed and the changes in the distribution and geometry of cooling bores were proposed.

Influence of an Aluminide Coating on the TMF Life of a Single Crystal Nickel-Base Superalloy

1998 ◽  
Author(s):  
Ernst E. Affeldt
Keyword(s):  
Single Crystal ◽  
Aluminide Coating ◽  
Turbine Blades ◽  
Temperature Cycling ◽  
Nickel Base Superalloy ◽  
Test Results ◽  
Bending Tests ◽  
Quantitative Correlation ◽  
Nickel Based Superalloy ◽  
Nickel Base

TMF tests were conducted with bare and aluminide coated single crystal nickel-based superalloy specimens. Temperature cycling was between 400°C and 1100°C with a phase shift (135°) which is typical for damaged locations on turbine blades. Stress response is characterized by a constant range and the formation of a tensile mean stress as a result of relaxation in the high temperature part of the cycle which is in compression. Bare specimens showed crack initiation from typical oxide hillocks. Coated specimens showed life reduction with respect to the bare ones caused by brittle cracking of the coating in the low temperature part of the cycle. Isothermal bending tests of coated specimens confirmed the low ductility of the coating at tempeatures below 600°C but quantitative correlation with the TMF test results failed.

GA Wavelet Transform Direction for γ-Phase Shaped Finite Element Analysis

2013 ◽  
Vol 791-793 ◽  
pp. 573-576
Author(s):  
Lei Meng
Keyword(s):  
Finite Element ◽  
Single Crystal ◽  
Phase Distribution ◽  
Tensile Creep ◽  
Von Mises Stress ◽  
Initial Population ◽  
Two Phase ◽  
Element Analysis ◽  
Multimodal Function ◽  
Von Mises

1040 °C was studied during the period imposed 137MPa tensile creep nickel-base single crystal superalloys γ/γ the evolution of two-phase approach. ANSYS finite element method is using a single crystal alloy with / without external load when the Von Mises stress in the gand γ two phase distribution. The comprehensive analysis of the formula, the coefficient values usually experience, not very accurate, this article dealing with GA coefficient. This algorithm uses orthogonal crossover to generate initial population and uses elitist-crossover to increase the good patterns of the population and uses hybrid mutation to increase the ability of local and global optimization. It has shown fascinating results when being used in the optimization of multimodal function. The results showed that: In the creep period, the corresponding cubic γ along the von Mises stress and strain energy density of the crystal face to form raft-like organizations.

Numerical Study on Elastic-Plastic Stress Field Near the Cooling Holes of Nickel-Based Single Crystal Air-Cooled Blades

2006 ◽  
Vol 324-325 ◽  
pp. 563-566 ◽  
Author(s):  
Qing Min Yu ◽  
Zhu Feng Yue ◽  
Yong Shou Liu
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Numerical Study ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Slip Systems ◽  
Stress Distributions ◽  
Elastic Plastic ◽  
Von Mises ◽  
Plastic Stress

In this paper, a plate containing a central hole was used to simulate gas turbine blade with cooling hole. Numerical calculations based on crystal plasticity theory have been performed to study the elastic-plastic stress field near the hole under tension. Two crystallographic orientations [001] and [111] were considered. The distributions of resolved shear stresses and strains of the octahedral slip systems {110}<112> were calculated. The results show that the crystallographic orientation has remarkable influence on both von Mises stress and resolved shear stress distributions. The resolved shear stress distributions around the hole are different between the two orientations, which lead to the different activated slip systems. So the deformed shape of the hole in [001] orientation differs from that in [111] orientation.

scholarly journals Effects of Crystal Orientations on the Low-Cycle Fatigue of a Single-Crystal Nickel-Based Superalloy at 980 °C

2018 ◽  
Vol 32 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Liu Liu ◽  
Jie Meng ◽  
Jin-Lai Liu ◽  
Hai-Feng Zhang ◽  
Xu-Dong Sun ◽  
...  
Keyword(s):  
Single Crystal ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Nickel Based Superalloy ◽  
Crystal Orientations

scholarly journals Impact of Shot-Peening on a Single Crystal Nickel-Based Superalloy

2014 ◽  
Vol 996 ◽  
pp. 70-75 ◽  
Author(s):  
Amélie Morancais ◽  
Mathieu Fevre ◽  
Manuel François ◽  
Pascale Kanoute ◽  
Serge Kruch ◽  
...  
Keyword(s):  
Single Crystal ◽  
Shot Peening ◽  
Turbine Blades ◽  
High Pressure Turbine ◽  
X Ray ◽  
Depth Profiles ◽  
Nickel Based Superalloy ◽  
Alloy Microstructure ◽  
The Impact ◽  
Compressive Residual Stresses

Shot-peening is used to improve the lifetime of mechanical components through the introduction of compressive residual stresses (RS) in a surface layer. In this study, we investigate the impact of such a pre-stressing treatment on a single crystal nickel-based superalloy for high pressure turbine blades of engine aircrafts. In addition to conventional metallographic tools used to characterize the alloy microstructure and the zone affected by shot-peening, X-ray measurements have been performed in order to determine residual stress depth profiles.

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