scholarly journals Numerical Simulation of Directional Solidification Process of Single Crystal Ni- Based Superalloy Casting

2017 ◽  
Vol 17 (2) ◽  
pp. 111-118 ◽  
Author(s):  
D. Szeliga ◽  
K. Kubiak ◽  
J. Sieniawski
Keyword(s):  
Temperature Gradient ◽  
Single Crystal ◽  
Cooling Rate ◽  
Solidification Rate ◽  
Solidification Process ◽  
Longitudinal Section ◽  
Withdrawal Rate ◽  
Bottom Part ◽  
Rate Maximum ◽  
Predicted Values

Abstract The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould (3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5 and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

scholarly journals Study on the Solidification Behavior of Inconel617 Electron Beam Cladding NiCoCrAlY: Numerical and Experimental Simulation

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Jian Chen ◽  
Hailang Liu ◽  
Zhiguo Peng ◽  
Jie Tang
Keyword(s):  
Electron Beam ◽  
Temperature Gradient ◽  
Cooling Rate ◽  
Molten Pool ◽  
Solidification Rate ◽  
Solidification Process ◽  
The Self ◽  
Cooling Effect ◽  
Tissue Structure ◽  
Solidification Behavior

To better control the Inconel617 electron beam cladding solidification process, a three-dimensional temperature field model was built to simulate the temperature gradient, cooling rate, and solidification rate in the solidification process and take a deep dive into the solidification behavior, as well as the calculation of the solidification characteristic parameters at the edge of the molten pool and then predict the solidification tissue structure. The study shows that the largest temperature gradient occurred in the material thickness direction. The self-cooling effect of the material dominated the solidification of the alloy layer; the cooling rate depended on the high-temperature thermal conductivity of the material and the self-cooling effect of the matrix, and the maximum cooling rate in the bonding zone was 1380 °C/s. The steady-state solidification rate was equal to the moving speed of the heat source; the solidification characteristics of the solidification process at the edge of the molten pool increased with the distance from the surface: the cooling rate decreased from 1421.61 to 623 °C/s, the temperature gradient increased from 0.0723 × 106 to 0.417 × 106, and the solidification rate decreased from 0.01 to 0 m/s. The prediction was made that the small and thin equiaxed crystals are on the top, a thin and short dendritic transition structure in the middle, and relatively coarse dendrites at the bottom. Experiments confirmed that the solidification tissue structure is basically consistent with the simulation law.

scholarly journals The Effect of Withdrawal Rate on Crystal Structure Perfection, Microstructure and Creep Resistance of Single Crystal Castings Made of CMSX-4 Nickel-Based Superalloy

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3422 ◽  
Author(s):  
Kamil Gancarczyk ◽  
Maciej Zubko ◽  
Aneta Hanc-Kuczkowska ◽  
Barbara Kościelniak ◽  
Robert Albrecht ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Creep Resistance ◽  
Solidification Process ◽  
Nickel Superalloy ◽  
Withdrawal Rate ◽  
X Ray Diffraction ◽  
Creep Tests ◽  
Nickel Based Superalloy ◽  
Tem Microscopy

This study focuses on the evaluation of the crystal structure perfection in the single crystal made of CMSX-4 nickel superalloy and its effect on creep resistance. Single crystal castings were manufactured by directional solidification process at the withdrawal rate of 1, 3, 5 and 7 mm/min. Light (LM) and electron (SEM, TEM) microscopy, X-ray diffraction and Mossbauer spectroscopy were used for evaluation of the microstructure and crystal structure perfection. Castings were also subjected to creep tests. The best creep resistance was obtained for the casting manufactured at the withdrawal rate of 3 mm/min, characterized by the highest crystal structure perfection compared to the other castings examined.

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.

Effect of Ta on the Solidification Behavior of Ni3Al-Base Single-Crystal Superalloys

2014 ◽  
Vol 788 ◽  
pp. 426-432 ◽  
Author(s):  
Tian Tian Zheng ◽  
Shu Suo Li ◽  
Yan Ling Pei ◽  
Cheng Ai ◽  
Sheng Kai Gong
Keyword(s):  
Differential Scanning Calorimetry ◽  
Single Crystal ◽  
Early Stage ◽  
Solidification Rate ◽  
Solidification Process ◽  
Primary Phase ◽  
Isothermal Quenching ◽  
Solidification Behavior ◽  
Scanning Calorimetry

Two kinds of Ni3Al-base SC superalloys, including IC31A (3wt.%Ta) and IC31B (6wt.%Ta) were investigated in the present study by using the differential scanning calorimetry (DSC) and isothermal quenching technology. The results showed that the larger amount of blocky γ′ phases existed in IC31B than that in IC31A. In the solidification process, the primary phase in IC31B was γ′ phases while in alloy IC31A the primary phase was γ phases. Besides, the solidification rate of IC31B in the early stage was lower than that in IC31A.

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.

Influence of withdrawal rate on the microstructure of Ni-base single-crystal superalloys containing Re and Ru

2011 ◽  
Vol 509 (19) ◽  
pp. 5866-5872 ◽  
Author(s):  
Gang Liu ◽  
Lin Liu ◽  
Cheng Ai ◽  
Bingming Ge ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Withdrawal Rate

scholarly journals Study of the Effect of Carbon on the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 982 ◽  
Author(s):  
Dazhi Pu ◽  
Guanghua Wen ◽  
Dachao Fu ◽  
Ping Tang ◽  
Junli Guo
Keyword(s):  
Surface Roughness ◽  
Cooling Rate ◽  
Solidification Process ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Peritectic Steel ◽  
Laser Confocal Microscope ◽  
Initial Solidification

In the continuous casting process, the shrinkage of the peritectic phase transition during the initial solidification process has an important influence on the surface quality of peritectic steel. The initial solidification process of 0.10C%, 0.14C%, and 0.16C% peritectic steels was observed in situ by a high temperature laser confocal microscope, and the contraction degree during initial solidification was characterized by surface roughness. The results showed that under the cooling rate of 20 °C/s, the surface roughness value Ra(δ/γ) of 0.10C% peritectic steel was 32 μm, the Ra(δ/γ) value of 0.14C% peritectic steel was 25 μm, and the Ra(δ/γ) value of 0.16C% peritectic steel was 17 μm. With increasing carbon content, the contraction degree of the δ→γ transformation decreased, and the value of the surface roughness Ra(δ/γ) declined. Therefore, surface roughness can characterize the contraction degree of the δ→γ transformation in the initial solidification process of peritectic steel under the condition of a large cooling rate.

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