MICROSTRUCTURAL EVOLUTION OF DIRECTIONALLY SOLIDIFIED Ni--BASED SUPERALLOY DZ125 UNDER PLANAR GROWTH

2010 ◽  
Vol 46 (9) ◽  
pp. 1075-1080 ◽  
Author(s):  
Zhixian MIN ◽  
Jun SHEN ◽  
Lingshui WANG ◽  
Zhourong FENG ◽  
Lin LIU ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Directionally Solidified ◽  
Planar Growth

Effect of Elements on Hot Tearing of Directionally Solidified Ni-Based Superalloys

2010 ◽  
Vol 150-151 ◽  
pp. 975-978
Author(s):  
Yan Li Wang ◽  
Zhao Hui Huang ◽  
Xi Hong Zhao ◽  
Jia Rong Li
Keyword(s):  
Directional Solidification ◽  
Microstructural Evolution ◽  
Hot Tearing ◽  
Directionally Solidified ◽  
Al Content ◽  
Hot Tearing Susceptibility

The effect of elements such as Ti, Al, Hf, Zr and B on hot tearing susceptibility during directional solidification was explored by tube-like samples with thickness of 1.0 mm, 1.5mm and 2.0mm in wall. Results of SEM of elements on solidification of casting Ni-based superalloys were presented. The influential extent among the investigated elements is found to be: the largest is Ti, then Zr, B and Al, and Hf is the smallest. Titanium promotes the formation of (γ+γ´) eutectic, increases sizes of the eutectic. Increasing Al content results in the size of γ+γ´ eutectic and the number of γ´. Increasing Zr content promotes γ+γ´ eutectic.Varying B content shows little microstructural evolution.

Microstructural evolution of a directionally solidified nickel-base superalloy during thermal fatigue

Rare Metals ◽  
2011 ◽  
Vol 30 (S1) ◽  
pp. 477-481 ◽  
Author(s):  
Pengcheng Xia ◽  
Lei Yang ◽  
Jinjiang Yu ◽  
Xiaofeng Sun ◽  
Hengrong Guan ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Thermal Fatigue ◽  
Nickel Base Superalloy ◽  
Directionally Solidified ◽  
Nickel Base ◽  
Base Superalloy

Influence of growth parameters on the microstructure of directionally solidified Bi2Sr2CaCu2Oy

1990 ◽  
Vol 5 (9) ◽  
pp. 1834-1849 ◽  
Author(s):  
M. J. Cima ◽  
X. P. Jiang ◽  
H. M. Chow ◽  
J. S. Haggerty ◽  
M. C. Flemings ◽  
...  
Keyword(s):  
Growth Rate ◽  
Directional Solidification ◽  
Growth Rates ◽  
Growth Parameters ◽  
Directionally Solidified ◽  
Primary Solidification Phase ◽  
Float Zone ◽  
The Matrix ◽  
Laser Heated ◽  
Planar Growth

Laser-heated float zone growth was used to study the directional solidification behavior of Bi–Sr–Ca–Cu–O superconductors. The phases that solidify from the melt, their morphology, and their composition are altered by growth rate. Highly textured microstructures are achieved by directional solidification at all growth rates. The superconducting phase is found always to have the composition Bi2.5Sr2CaCu2.2Oy when grown from boules with composition 2:2:1:2 (BiO1.5:SrO:CaO:CuO). Planar growth fronts of Bi2.5Sr2CaCu2.2Oy are observed when the temperature gradient divided by the growth rate (G/R) is larger than 3 ⊠ 1011 K-s/m2 in 2.75 atm oxygen. Thus, the 2212 compound was observed to solidify directly from the melt at the slowest growth rates used in this study. Measurement of the steady-state liquid zone composition indicates that it becomes bismuth-rich as the growth rate decreases. Dendrites of the primary solidification phase, (Sr1−xCax)14Cu24Oy, form in a matrix of Bi2.5Sr2CaCu2.2Oy when G/R is somewhat less than 3 ⊠ 1011 K-s/m2. Observed microstructures are consistent with a peritectic relationship among Bi2.5Sr2CaCu2.2Oy, (Sr1−xCax)14Cu24Oy (x = 0.4), and a liquid rich in bismuth at elevated oxygen pressure. At lower values of G/R, Sr3Ca2Cu5Oy is the primary solidification phase and negligible Bi2.5Sr2CaCu2.2Oy forms in the matrix.

Microstructural Changes during Thermal Fatigue in a Nickel-Base Directionally Solidified Superalloy

2013 ◽  
Vol 807-809 ◽  
pp. 2722-2725
Author(s):  
Kai Zhao
Keyword(s):  
Phase Transformation ◽  
Microstructural Evolution ◽  
Thermal Fatigue ◽  
Directionally Solidified ◽  
Microstructural Changes ◽  
The Matrix ◽  
Nickel Base

Microstructural evolution of a nickel-base directionally solidified superalloy during thermal fatigue was investigated. Three kinds of phase transformation have been observed: μ phase precipitated due to the relatively increasing of the concentration of forming μ phase elements as a result of the depletion of Al and Cr; Script-like carbides and γ phase dissolved into the matrix. Also, thermal fatigue was strongly influenced by oxidation.

Monotectic Al–Bi–Sn alloys directionally solidified: Effects of Bi content, growth rate and cooling rate on the microstructural evolution and hardness

2015 ◽  
Vol 653 ◽  
pp. 243-254 ◽  
Author(s):  
Thiago A. Costa ◽  
Emmanuelle S. Freitas ◽  
Marcelino Dias ◽  
Crystopher Brito ◽  
Noé Cheung ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cooling Rate ◽  
Microstructural Evolution ◽  
Directionally Solidified
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