Grain Competition Mechanism of a Ni3Al-Based Single Crystal Superalloy IC6SX

2013 ◽  
Vol 747-748 ◽  
pp. 797-803 ◽  
Author(s):  
Li Wu Jiang ◽  
Shu Suo Li ◽  
Mei Ling Wu ◽  
Ya Fang Han
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Processing Parameters ◽  
Growth Direction ◽  
Selection Method ◽  
Single Crystal Superalloy ◽  
Competitive Growth ◽  
Deviation Angle ◽  
Spiral Grain ◽  
Competition Mechanism

The grain competitive growth and elimination during the directional solidification of a Ni3Al-base single crystal superalloy IC6SX prepared by spiral grain selection method was studied systematically. The experimental results revealed that there were 5 kinds of mechanism during the grain competitive growth and elimination. The grains with preferred growth direction and smaller deviation angle to growth direction have stronger competitiveness, and the mutual thwarting of dendrites played an important role in the processing of grains competitive growth. The results can explain the competitive growth mechanism during the directional solidification and can be used to optimize processing parameters to lay an important foundation for improving preparation processes of single crystal superalloys.

Prediction of Grain Formation and Defects during Solidification in Single Crystal Superalloy Castings

2021 ◽  
Vol 1035 ◽  
pp. 819-826
Author(s):  
Hai Peng Jin ◽  
Shi Zhong Liu ◽  
Hong Ji Xie ◽  
Jia Rong Li
Keyword(s):  
Single Crystal ◽  
Large Deviation ◽  
Solidification Process ◽  
Orientation Distribution ◽  
Single Crystal Superalloy ◽  
Competitive Growth ◽  
Initial Nucleation ◽  
Grain Formation ◽  
Orientation Deviation ◽  
Stray Grains

Numerical simulation and prediction of grain formation and defects, including the stray grain and high angle orientation deviation during directional solidification process of a single crystal superalloy hollow turbine blade are experimentally conducted by means of commercial software ProCAST and backscattering scanning electron microscope. The results show that the initial nucleation amount at the beginning section of the starter block is 104 of magnitude, and the number of grains decreases gradually with the competitive growth, and the number is about 100 at the spiral of the selector. And the orientation distribution of grains is close to <001> direction, with the orientation deviation between 10° and 15°. Moreover, with the increase of withdrawal rate, the curvature of isoline of liquidus of single crystal blade increases, and the tendency to form stray grains defects increases. The grain with a large deviation from orientation blocks the growth of other grains at the first rotating transition site of the selector, and then gradually grows and solidifies to form the final blade.

Modeling of grain selection during directional solidification of single crystal superalloy turbine blade castings

JOM ◽  
2010 ◽  
Vol 62 (5) ◽  
pp. 30-34 ◽  
Author(s):  
Dong Pan ◽  
Qingyan Xu ◽  
Baicheng Liu ◽  
Jiarong Li ◽  
Hailong Yuan ◽  
...  
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Turbine Blade ◽  
Single Crystal Superalloy ◽  
Superalloy Turbine Blade

Directional Solidification Behavior of CMSX-6 Superalloy

2014 ◽  
Vol 788 ◽  
pp. 554-559
Author(s):  
Shuai Zheng ◽  
Yu Liang Jia ◽  
Jiao Tang
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Thermal Gradient ◽  
First Generation ◽  
Primary Dendrite ◽  
Solidification Rate ◽  
Experimental Results ◽  
Single Crystal Superalloy ◽  
Solidification Behavior ◽  
Rate Range

The directional solidification behavior of a first generation single crystal superalloy CMSX-6 was investigated. The solidification rate range in 25μm/s to 100μm/s and a thermal gradient G of 30K/cm were used for the present study. The experimental results show that the primary dendrite arm space (PDAS) decreased from (432±8) μm to (369±4) μm as the solidification rate increased, and the sizes of the eutectic pools also decreased as the solidification rate increased. And the volume fractions of eutectic γ/γ' were about 7% to 9% with different solidification rate. The γ/γ'- eutectic was comprised with coarse γ' phase and fine γ/γ' network. The morphology of the γ/γ’ eutectic supported the possibility that the solidification of γ/γ’ eutectic initiates with the formation of fine γ/γ’.

Grain Competitive Growth Prediction during Solidification in Single Crystal Superalloy DD6 Castings

2014 ◽  
Vol 783-786 ◽  
pp. 2148-2153
Author(s):  
Hai Peng Jin ◽  
Jia Rong Li
Keyword(s):  
Single Crystal ◽  
Cross Sections ◽  
Three Dimensional ◽  
Single Crystal Superalloy ◽  
Competitive Growth ◽  
Chill Surface ◽  
Stress Orientation ◽  
Ca Model ◽  
Ebsd Method ◽  
Competition Growth

Competitive growth and grain selection were simulated and analyzed during the directional solidification with the conditions for single crystal superalloy DD6 castings using Commercial software, ProCAST. A three dimensional cellular automaton (CA) model coupled with finite-element (FE) heat flow calculation was applied. Measurements at the grain scale were made using the EBSD method at the cross sections in the starter block and grain selector at an interval of 4 mm from the chill surface. The grain characteristics and the rules of competition growth were obtained. The validity of the simulation results were compared with those of the experiment. It concluded that the model-predicted tendency shows satisfactory agreement with the experiment. Increasing the distance from the chill decreases the number of grains, increases the radius of grains and drives the crystallization orientation of grains to principal stress orientation.

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