scholarly journals Characterization of Microstructure, Precipitations and Microsegregation in Laser Additive Manufactured Nickel-Based Single-Crystal Superalloy

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2300 ◽  
Author(s):  
Zhaoyang Liu ◽  
Jiayang Shu
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Treatment Process ◽  
Three Dimensional ◽  
Subsequent Heat Treatment ◽  
Single Crystal Superalloy ◽  
Wall Structure ◽  
Thin Wall ◽  
Heat Treatment Process ◽  
Dimensional Network

In this study, the microstructure, precipitations, and microsegregation in the laser additive manufactured thin-wall structure of a single-crystal superalloy are synthetically characterized. The influence of a subsequent heat treatment on the microstructure and precipitations is discussed. The results show that under the given processing conditions, the single-crystal microstructure is regenerated perfectly with small misorientation angles in the thin-wall structure. The crystal morphology shows obvious diversity and instability with the incremental height of thin-wall structure. With the increase of manufacturing height, both the primary and secondary dendritic arm spacings of epitaxial columnar dendrites first increase rapidly and then reach a dynamic balanced state. The distribution of precipitations and pores keeps symbiosis in the interdendritic region and shows periodic band characteristic with high density in the band region and low density in the inner region of plate layers. The microsegregation of element atoms in the microstructure shows a three-dimensional network distribution. The concentration of element atoms keeps good consistency with high value in the three-dimensional network and nearly standard value in the outside region. The subsequent heat treatment process contributes to the occupation of as-processed pores by the expanded mature precipitations with good blocky shape. Further optimization of the heat treatment process for improving the lattice coherency of precipitated γ’ phase and γ matrix in the laser additive manufactured single-crystal superalloy is needed and valuable.

Numberical Simulation of Welding Deformation under Different Conditions

2012 ◽  
Vol 538-541 ◽  
pp. 1439-1442
Author(s):  
Qing Yang ◽  
Shu Jun Xie ◽  
Hai Tao Gao
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Treatment Process ◽  
Three Dimensional ◽  
Angular Distortion ◽  
Solid Model ◽  
Heat Treatment Process ◽  
Cooling Process ◽  
Finite Element Software ◽  
Set Up

To simulate the welding and heat treatment process of the Q345 plate with V-groove, Finite element software ANSYS was employed. A reasonable three-dimensional solid model was set up by using element birth and death technology to simulate the formation of the weld. Constraint was applied on both sides of the base metal in the welding and cooling process. Then constraint was removed when the specimen was cooled to room temperature, the angular distortion of welding increases by 75.03% after the constraint is removed. Then heat treatment was conducted on the plate of which the constraint was removed. The deformation results show that after heat treatment the angular distortion is reduced to 30.37% of the value before heat treatment.

Optimization of Heat Treatment Process of ZE41A Magnesium Alloy Using Grey- Based Taguchi Method

2008 ◽  
Vol 3 (2) ◽  
pp. 63-69
Author(s):  
M. Sivapragash ◽  
◽  
V. Sateeshkumar ◽  
P.R. Lakshminarayanan ◽  
R. Karthikeyan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Taguchi Method ◽  
Treatment Process ◽  
Heat Treatment Process

EFFECT ON HARDNESS and MICRO STRUCTURAL BEHAVIOUR OF TOOL STEEL AFTER HEAT TREATMENT PROCESS

2017 ◽  
Vol 4 (24) ◽  
Author(s):  
Karanbir Singh ◽  
Aditya Chhabra ◽  
Vaibhav Kapoor ◽  
Vaibhav Kapoor
Keyword(s):  
Heat Treatment ◽  
Empirical Study ◽  
Tool Steel ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Structural Behaviour ◽  
Treatment Processes ◽  
En 31

This study is conducted to analyze the effect on the Hardness and Micro Structural Behaviour of three Sample Grades of Tool Steel i.e. EN-31, EN-8, and D3 after Heat Treatment Processes Such As Annealing, Normalizing, and Hardening and Tempering. The purpose of Selecting Tool Steel is Because Tool Steel is Mostly Used in the Manufacturing Industry.This study is based upon the empirical study which means it is derived from experiment and observation rather than theory.

scholarly journals Creep Damage Repair of a Nickel-Based Single Crystal Superalloy Based on Heat Treatment

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 623
Author(s):  
Xiaoyan Wang ◽  
Meng Li ◽  
Yuansheng Wang ◽  
Chengjiang Zhang ◽  
Zhixun Wen
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Creep Damage ◽  
Primary Creep ◽  
Single Crystal Superalloy ◽  
Secondary Creep ◽  
Creep Life ◽  
Phase Coarsening ◽  
Damage Repair ◽  
Creep Time

Taking nickel-based single crystal superalloy DD6 as the research object, different degrees of creep damage were prefabricated by creep interruption tests, and then the creep damage was repaired by the restoration heat treatment system of solid solution heat treatment and two-stage aging heat treatment. The results show that with the creep time increasing, the alloy underwent microstructure evolution including γ′ phase coarsening, N-type rafting and de-rafting. After the restoration heat treatment, the coarse rafted γ′ phase of creep damaged specimens dissolved, precipitated, grew up, and became cubic again. Except for the specimens with creep interruption of 100 h, the γ′ phase can basically achieve the same arrangement as the γ′ phase of the original sample. The comparison of the secondary creep test shows that the steady-state creep stage of the test piece after the restoration heat treatment is relatively increased, and the total creep life can reach the same level as the primary creep life. The high temperature creep properties of the tested alloy are basically recovered, and the restoration heat treatment effect is good.

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