A Study on the Formation of Serrated Grain Boundaries and its Applications in Nimonic 263

2010 ◽  
Vol 638-642 ◽  
pp. 2245-2250 ◽  
Author(s):  
Hyun Uk Hong ◽  
Hi Won Jeong ◽  
In Soo Kim ◽  
Baig Gyu Choi ◽  
Young Soo Yoo ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Creep Resistance ◽  
Solution Treatment ◽  
Interfacial Free Energy ◽  
Treatment Temperature ◽  
M23c6 Carbide ◽  
Solution Treatment Temperature ◽  
Lattice Image ◽  
Nickel Based Superalloy

The formation of serrated grain boundaries and its subsequent effect on creep resistance have been investigated in a wrought nickel based superalloy Nimonic 263. The grain boundaries were considerably serrated without the presence of γ' phases or M23C6 when a specimen was slow-cooled from the solution treatment temperature. The high resolution observation on the lattice image of the serrated grain boundary suggested that the grain boundaries tended to serrate to have specific segments approaching to one {111} low-index plane at a boundary in order to have lower interfacial free energy of grain boundary. The grain boundary serration led to a change in M23C6 carbide characteristics: the carbide morphology from granular to planar, a lowered density and their coherency pattern to two neighboring grains from consistent to zigzag. The improvement of creep resistance was noticeably observed by the introduction of GB serration without deterioration of basic mechanical properties. This improvement in creep resistance by the serration was associated with a lower rate of cavitation and crack propagation through the modification of carbide characteristics as well as grain boundary configuration.

The Potential of HAZ Property Improvement through Control of Grain Boundary Character in a Wrought Ni-Based Superalloy

2010 ◽  
Vol 654-656 ◽  
pp. 488-491 ◽  
Author(s):  
Hyun Uk Hong ◽  
In Soo Kim ◽  
Baig Gyu Choi ◽  
Hi Won Jeong ◽  
Seong Moon Seo ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Solution Treatment ◽  
Crystallographic Analysis ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Slow Cooling ◽  
Grain Coarsening ◽  
Boundary Character ◽  
Grain Boundary Character

The effects of grain boundary serration on grain coarsening and liquation behavior in simulated weld heat-affected-zone (HAZ) of a wrought Ni-based superalloy Alloy 263 have been investigated. Recently, the present authors have found that grain boundary serration occurs in the absence of adjacent coarse γ' particles or M23C6 carbides when a specimen is direct-aged with a combination of slow cooling from solution treatment temperature to aging temperature. This serration leads to a change in grain boundary character as special boundary based on the crystallographic analysis demonstrating that the grain boundaries tend to serrate to have specific segments approaching to one {111} low-index plane at a boundary. The present study was initiated to investigate the interdependence of the serration and HAZ property with a consideration of this serration as a potential for the use of a damage-tolerant microstructure. It was found that the serrated grain boundaries suppress effectively grain coarsening, and are highly resistant to liquation cracking in HAZ due to their lower tendency to be wetted and penetrated by the liquid phase. These results reflect closely a significant decrease in interfacial energy as well as grain boundary configuration by the serration.

Influence of Overburning on Microstructure and Property of 6061 Aluminum Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 118-121 ◽  
Author(s):  
Shi Xing Zhang ◽  
Shao Min Qu
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Grain Boundary ◽  
Solution Treatment ◽  
Hardness Test ◽  
Treatment Temperature ◽  
Experimental Results ◽  
Solution Treatment Temperature ◽  
6061 Aluminum Alloy ◽  
Microstructure And Mechanical Properties

Process of solution treatment of 6061 aluminum alloy was done by hardness test and microanalysis in this paper. The effects of different solution treatment temperature on the microstructure and mechanical properties of 6061 aluminum alloy were studied and the influence of overburning on the microstructure and mechanical properties of 6061 aluminum alloy were also analyzed. The experimental results show that overburning occurring while 6061 aluminum alloy is heated above 580°C . The hardness measurements and microstructure analysis results show that the hardness decreased, grain boundary becomes trigemanal and compounded –melting structure (burnt structure) appeared when overburning occuring for this alloy .

Effect of Solid Solution Treatment on Corrosion Resistance of Al-Cu-Mg-Ag Alloy

2021 ◽  
Vol 1032 ◽  
pp. 213-219
Author(s):  
Zhen Hua Cui ◽  
Xiao Yan Liu ◽  
Yan Qin Wang ◽  
Hong Ru Yang ◽  
Zhen Jie Cui ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Grain Boundary ◽  
Intergranular Corrosion ◽  
Solution Treatment ◽  
Electrochemical Corrosion ◽  
Treatment Temperature ◽  
Boundary Structure ◽  
Solution Treatment Temperature ◽  
Grain Boundary Structure ◽  
Electrochemical Corrosion Resistance

In this experiment, Al-Cu-Mg-Ag alloy was used as material and solution temperature was used as variable to investigate its effect on the corrosion properties of the alloy and Hardness test, metallographic observation, electrochemical test, intergranular corrosion and exfoliation corrosion test were carried out on three groups of samples. The results show that the intergranular corrosion resistance of the alloy decreases with the increase of solution treatment temperature, and the sample treated at 505 °C has the best performance. This is mainly because grain boundary structure plays a role in increasing PFZ and expanding corrosion channels. The exfoliation corrosion resistance of Al-Cu-Mg-Ag alloy increases first and then decreases, and the sample treated at 515 °C has the best performance. This is due to the dual effects of grain boundary structure and grain morphology. On the one hand, the solution treatment temperature increases, which widens the precipitation-free zone and reduces the electrochemical corrosion resistance of the alloy. On the other hand, the increase of recrystallized grains decreases the cohesion of corrosion products and enhances the electrochemical corrosion resistance of the alloy.

Influence of Overburning on Microstructure and Property of 2024 Aluminum Alloy

2014 ◽  
Vol 941-944 ◽  
pp. 3-7 ◽  
Author(s):  
Shi Xing Zhang ◽  
Yu Ping Zhu ◽  
Gang Yi Cai
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Grain Boundary ◽  
Solution Treatment ◽  
Hardness Test ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
2024 Aluminum Alloy ◽  
Microstructure And Mechanical Properties ◽  
Hardness Tests

Process of solution treatment of 2024 aluminum alloy was done by hardness test and microanalysis in this paper. The effects of different solution treatment temperature on the microstructure and mechanical properties of 2024 aluminum alloy were studied and the influence of overburning on the microstructure and mechanical properties of 2024 aluminum alloy were also analyzed. The experimental results show that overburning occurs while 2024 aluminum alloy is heated over 490°C×50min . The hardness tests and microstructure analysis results show that the hardness decreased, grain boundary becomes trigemanal and compounded –melting structure (burnt structure) appeared when overburning occuring for this alloy .

scholarly journals Effect of Solution Temperature on the Microstructure and Properties of TB10 Titanium Alloy Bars

2021 ◽  
Vol 2076 (1) ◽  
pp. 012081
Author(s):  
Zheng Luo ◽  
Zhouming Tan ◽  
Yanguang Wei ◽  
Xuefei Cui ◽  
Haiming Tao
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Titanium Alloy ◽  
Grain Boundary ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Solution Temperature ◽  
Solution Treatment Temperature ◽  
Β Phase ◽  
Strength And Plasticity

Abstract This paper studies the effect of solution temperature on the microstructure and mechanical properties of TB10 titanium alloy bars. The results show that the microstructure is composed of β phase and primary α phase (αp) when solution treatment is below the phase transition temperature. With the increase of the solution temperature, the β phase grain size in the microstructure increases, the thickness of the grain boundary decreases, and the number and size of the αp phase decrease, so that the strength of the alloy decreases and the plasticity increases. When the solution treatment temperature is 800°C, the reticulated grain boundary αp phase causes the plasticity to drop rapidly. When the solution treatment temperature is above the phase transition point, as the solution temperature rises, the β phase re-nucleates and grows, the grain size increases, the number of αp phase decreases. The super-cooled β phase grains induce martensite phenomenon due to stress, which eventually causes the strength and plasticity to decrease.

Changes in Microstructure of Biomedical Co-Cr-Mo-C Alloys with Solution Treating and Aging

2010 ◽  
Vol 89-91 ◽  
pp. 377-382 ◽  
Author(s):  
S. Mineta ◽  
Shigenobu Namba ◽  
Takashi Yoneda ◽  
Kyosuke Ueda ◽  
Takayuki Narushima
Keyword(s):  
Solution Treatment ◽  
Heating Time ◽  
Treatment Temperature ◽  
Vacuum Furnace ◽  
Solution Treatment Temperature ◽  
Precipitate Dissolution ◽  
Heat Treated ◽  
M23c6 Type ◽  
Type Carbide ◽  
Time Required

Microstructural changes occurring in biomedical Co-Cr-Mo alloys with three carbon levels due to solution treatment and aging were investigated. Ingots of Co-Cr-Mo alloys with three different carbon levels were prepared by vacuum furnace melting; their chemical composition was Co-28Cr-6Mo-xC (x = 0.12, 0.25 and 0.35 mass%). Precipitates were electrolytically extracted from as-cast and heat-treated alloys. An M23C6 type carbide and a phase were detected as precipitates in as-cast Co-28Cr-6Mo-0.12C alloy, and an M23C6 type carbide and an  phase (M6C-M12C type carbide) were detected in as-cast Co-28Cr-6Mo-0.25C and Co-28Cr-6Mo-0.35C alloys. Only the M23C6 type carbide was detected during solution treatment. Complete precipitate dissolution occurred in all the three alloys after solution treatment. The holding time required for complete precipitate dissolution increased with increasing carbon content and decreasing solution treatment temperature. Complete precipitate dissolution occurred in the Co-Cr-Mo-C alloys solution treated at 1523 K for 43.2 ks; they were then subjected to aging from 873 to 1473 K for a heating time up to 44.1 ks after complete precipitate dissolution in solution treatment at 1523 K for 43.2 ks. The M23C6 type carbide with a grain size of 0.1–3 m was observed after aging. A time-temperature-precipitation diagram of the M23C6 type carbide formed in the Co-28Cr-6Mo-0.25C alloy was plotted.

scholarly journals Influence of Solution Treatment Temperature on Various Properties of 21-4N Steel

DENKI-SEIKO ◽  
1970 ◽  
Vol 41 (4) ◽  
pp. 294-301
Author(s):  
Shôichi Fukui ◽  
Susumu Isobe ◽  
Hiroshi Hirayama
Keyword(s):  
Solution Treatment ◽  
Treatment Temperature ◽  
Solution Treatment Temperature
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