Effect of Thermal Gradient on Solidification Microstructure in the Ni-Base Single Crystal Superalloy CMSX10

2008 ◽  
Vol 273-276 ◽  
pp. 361-366 ◽  
Author(s):  
S.H. Kim ◽  
J.M. Kim ◽  
H.J. Lee ◽  
S.D. Son ◽  
J.H. Lee ◽  
...  
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Thermal Gradient ◽  
Solidification Rate ◽  
Planar Interface ◽  
Single Crystal Superalloy ◽  
Thermal Gradients ◽  
High Thermal Gradient ◽  
Cooling Media ◽  
Cold Chamber

A single crystal superalloy including 6 wt.% Re, CMSX10 was studied by directional solidification at various thermal gradients, 13 ~ 23oC/mm and solidification rates, 1~100 μm/s. A high thermal gradient could be obtained by applying the liquid metal, such as Ga-In, as a cooling media in directional solidification apparatus, and also by adjusting the cold chamber in the Bridgman system. As increasing the solidification rate, the planar interface changed to cellular and dendritic interfaces. The higher thermal gradient contributed to reducing the dendrite arm spacing effectively, which results in reducing the size of eutectic, as well as higher solidification rate. The length of the mushy zone decreased with increasing the thermal gradient and increased with increasing the solidification rate.

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’.

Interface Morphologies and Microstructure of a Single Crystal Superalloy under High Thermal Gradient Directional Solidification

2005 ◽  
Vol 475-479 ◽  
pp. 665-668 ◽  
Author(s):  
Lin Liu ◽  
Jun Zhang ◽  
Taiwen Hang ◽  
Heng Zhi Fu
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Cooling Rate ◽  
Thermal Gradient ◽  
Cellular Structure ◽  
Single Crystal Superalloy ◽  
Withdrawal Rate ◽  
High Rate ◽  
High Thermal Gradient ◽  
Withdrawal Speed

The interface morphologies single crystal superalloys CMSX-2 has been studied over a range of cooling rate with large variations in withdrawal speed in directional solidification. The superfine cellular structure was obtained under both high thermal gradient up to 1000K/cm and fast withdrawal rate up to 1mm/sec. The high rate directional solidification results in reduction in primary and secondary dendrite arm spacing, refinement of λ’ phase, reduced microsegregation of alloying elements and smaller size of γ-γ’ eutectics.

Microstructure Evolution with Solidification Rates in IN 738LC Superalloy

2006 ◽  
Vol 510-511 ◽  
pp. 450-453 ◽  
Author(s):  
H.C. Kim ◽  
Y.H. Kim ◽  
Yeon Gil Jung ◽  
Je Hyun Lee ◽  
Chang Yong Jo ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Morphological Evolution ◽  
Solidification Rate ◽  
Planar Interface ◽  
Interface Morphology ◽  
High Thermal Gradient ◽  
Solid Liquid Interface ◽  
Superalloy In738lc ◽  
Solid Liquid ◽  
Base Superalloy

The morphological evolution and growth mechanism of solidification interface with solidification rates were investigated in the Ni-base superalloy, IN738LC, by directional solidification and quenching technique under a relatively high thermal gradient of 20.5oC/mm. The planar interface of the MC-γ eutectic was found at the low solidification of 1 µm/s, and the dendritic interface formed above 5 µm/s. The dendrite lengths increased as increasing increasing solidification rate, and the dendrite tip temperature was close to the liquidus temperature at 50 µm/s. The carbide morphologies were blocky-type and rod-type in the planar interface of low solidification rates, and as the solidification rate increased, the carbide shape changed from script type to spotty type. The phase transformation temperatures from the dendrite to MC carbide and eutectic were estimated by DTA and by the solid/liquid interface morphology by directional solidification.

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

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.

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