Simultaneous neutron transmission and diffraction imaging investigations of single crystal nickel-based superalloy turbine blades

2016 ◽  
Vol 79 ◽  
pp. 109-113 ◽  
Author(s):  
S. Peetermans ◽  
E.H. Lehmann
Keyword(s):  
Single Crystal ◽  
Turbine Blades ◽  
Neutron Transmission ◽  
Nickel Based Superalloy ◽  
Diffraction Imaging

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).

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.

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.

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.

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

1999 ◽  
Vol 121 (4) ◽  
pp. 687-690 ◽  
Author(s):  
E. 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 deg) that 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 temperatures below 600°C but quantitative correlation with the TMF test results failed.

Optimization of x-ray Techniques for Nondestructive Characterization of Single Crystal Turbine Blades

1999 ◽  
Vol 591 ◽  
Author(s):  
J.M. Winter ◽  
K.G. Lipetzky ◽  
R.E. Green
Keyword(s):  
Single Crystal ◽  
Turbine Blades ◽  
Crystalline Perfection ◽  
X Ray ◽  
Diffraction Imaging ◽  
Nickel Based Alloy ◽  
Beam Transmission ◽  
Nondestructive Characterization

ABSTRACTThis paper describes nondestructive x-ray characterization techniques which detect macroscopic and microscopic defects, determine the overall crystallographic perfection, and detect any unwanted secondary crystals both on the external surface as well as in the interior of single crystal blades. The method of Asymmetric Crystal Topography for diffraction imaging the surfaces of single crystal turbine blades and the method of White Beam Transmission Topography for diffraction imaging through the thickness of single crystal turbine blades are both discussed and illustrated with representive diffraction images (topographs). It is clear that the images gained from these methods have a capability for providing information about the details of crystalline perfection (or lack thereof) in nickel-based alloy single crystal turbine blades. Such information can provide considerable leverage for the crystal grower to help in adjusting processing variables to enhance quality of a critical product. And the same methods of topography can conceiveably provide tools for evaluating the finished product in a way which has not been available to date.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

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