Anisotropic creep fracture mechanism and microstructural evolution in nickel-based single crystal specimen with a center film hole

By means of creep properties measurement and microstructure observation, an investigation has been made into the damage and fracture mechanism of a nickel-based single crystal superalloy during creep at moderate temperature. Results show that the deformation mechanism of the alloy in the latter stage of creep is that the primary-secondary slipping systems are alternately activated, and the micro-crack is firstly initiated on the γ′/γ phases interface in the intersection regions of two slip systems. As creep goes on, the micro-crack is propagated along the γ′/γ interface, which is perpendicular to stress axis, to form the square-like cleavage plane on the (001) plane. Thereinto, the propagation of the cracks on (001) plane is intersected with {111} cleavage plane which is secondly activated, which may terminate the propagation of the crack to form the cleavage plane with square-like feature on (001) plane along the <110> directions. Due to the multi-cracks may be propagated on different cross-section of the alloy during creep, and the tearing edge or secondary cleavage plane are formed along the direction with bigger shearing stress at the crack tip, which makes the multi-cracks connected each other until the occurrence of creep fracture, this is thought to be the main reason of the creep fracture having the uneven and multi-level cleavage characteristics.

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EFFECTS OF Ru AND Cr ON γ/γ' MICROSTRUCTURAL EVOLUTION OF Ni--BASED SINGLE CRYSTAL SUPERALLOYS DURING HEAT TREATMENT

ACTA METALLURGICA SINICA ◽

10.3724/sp.j.1037.2010.00108 ◽

2010 ◽

Vol 46 (8) ◽

pp. 897-906 ◽

Cited By ~ 18

Author(s):

Jingyang CHEN ◽

Bin ZHAO ◽

Qiang FENG ◽

Lamei CAO ◽

Zuqing SUN

Keyword(s):

Heat Treatment ◽

Single Crystal ◽

Microstructural Evolution

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Microstructural evolution of a single crystal nickel-base superalloy during thermal exposure

Materials Letters ◽

10.1016/s0167-577x(03)00359-8 ◽

2003 ◽

Vol 57 (29) ◽

pp. 4540-4546 ◽

Cited By ~ 38

Author(s):

L.R. Liu ◽

T. Jin ◽

N.R. Zhao ◽

Z.H. Wang ◽

X.F. Sun ◽

...

Keyword(s):

Single Crystal ◽

Microstructural Evolution ◽

Thermal Exposure ◽

Nickel Base Superalloy ◽

Nickel Base ◽

Base Superalloy

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Atomistic simulations of shock induced microstructural evolution and spallation in single crystal nickel

Journal of Applied Physics ◽

10.1063/1.2423084 ◽

2007 ◽

Vol 101 (4) ◽

pp. 043504 ◽

Cited By ~ 48

Author(s):

S. G. Srinivasan ◽

M. I. Baskes ◽

G. J. Wagner

Keyword(s):

Single Crystal ◽

Microstructural Evolution ◽

Atomistic Simulations

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Simulation of the External Pressure Influence on the Micro-Structural Evolution of a Single Crystal Ni-Based Superalloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.278.247 ◽

2011 ◽

Vol 278 ◽

pp. 247-252

Author(s):

Inmaculada Lopez-Galilea ◽

Stephan Huth ◽

Suzana Gomes Fries ◽

Ingo Steinbach ◽

Werner Theisen

Keyword(s):

Single Crystal ◽

Microstructural Evolution ◽

Phase Field ◽

Structural Evolution ◽

Field Method ◽

External Pressure ◽

Experimental Results ◽

Alloying Elements ◽

Phase Field Method

The phase field method has been applied to simulate the microstructural evolution of a commercial single crystal Ni-based superalloy during both, HIP and annealing treatments. The effects of applying high isostatic pressure on the microstructural evolution, which mainly retards the diffusion of the alloying elements causing the loss of the orientational coherency between the phases is demonstrated by the simulation and experimental results

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