Effects of Long-Term Aging at 1070°C on Microstructure and Mechanical Properties of Ni3Al-Base Alloy IC6E

The effect of long-term aging at 1070°C on microstructure and mechanical properties of Ni3Al-base equiaxed superalloy IC6E was investigated. The microstructure change during aging for periods of 100 to 1500h was examined by SEM . Results showed that alloy IC6E underwent following microstructure changes during aging: γ' phases coalesced and grew, γ phases became disconnected and coarsened, the content of Mo (the solution-hardening element of γ and γ' phases) in γ' phases decreased, Y-NiMo phases precipitated from γ phases both at grain boundaries and within grains, and γ' bands and large γ phases emerged along grain boundaries. The tensile and stress rupture properties after aging were determined. The results showed that the yield strength of alloy IC6E at room temperature decreased obviously after aging for 100 h, and reduced slowly during further aging. The stress rupture life under 1070°C, 80MPa also had no essential change during aging.

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Heat Treated Microstructure and Mechanical Properties of K492M Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.788.493 ◽

2014 ◽

Vol 788 ◽

pp. 493-497

Author(s):

Xiang Hui Li ◽

Lian Li ◽

Xin Tang ◽

Qi Dong Gai

Keyword(s):

Mechanical Properties ◽

Grain Boundary ◽

Interdendritic Region ◽

Rupture Life ◽

Stress Rupture ◽

Stress Rupture Life ◽

Stress Rupture Properties ◽

Heat Treated ◽

Columnar Grain ◽

Rupture Properties

The microstructure, tensile and stress rupture properties of K492Malloy have been investigated in the present study. The results revealed that γ matrix, γ′ phase, carbide and eutectic in the interdendritic region within grain interior and along grain boundary were observed after solidification. After heat treatment, γ' precipitates with two obviously distinct size existed in the dendrite core and interdendritic region, respectively. Meanwhile, the chain-like (W, Mo)6C and Cr23C6carbides precipitated along grain boundary. The investigation of mechanical properties suggested that the tensile strength was initially increased but then decreased with increasing the temperature from 25oC to 760oC. The stress rupture life was 68.2h and 35.8h at 760oC / 655MPa and 870oC / 365MP, respectively. The columnar grain and carbide along grain boundary resulted in intergranular brittle fracture in both test conditions. As a result, the elongation under the conditions of 760oC/655MPa and 870oC/365MP was 1.5% and 1.4%, respectively.

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Microstructure and Mechanical Properties of In718 Alloy Produced with Twin-Scanning Atomizer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.415 ◽

2007 ◽

Vol 561-565 ◽

pp. 415-418 ◽

Cited By ~ 2

Author(s):

Zheng Dong Li ◽

Guo Qing Zhang ◽

Zhou Li ◽

Wen Yong Xu ◽

Rui Ping Yao ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Tensile Strength ◽

Rupture Life ◽

Stress Rupture ◽

Spray Forming ◽

Microstructure And Mechanical Properties ◽

Stress Rupture Properties ◽

Direct Aging ◽

Rupture Properties

Sound billets were produced at BIAM with a twin-scanning spray forming facility. Microstructure and mechanical properties of In718 alloy produced with this technology were examined. Both tensile strength and stress rupture properties are excellent with the rupture life even doubled after received a direct aging heat treatment.

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NiCr-CrAl Coating for Ni3Al Base Alloy IC6AE

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.1467 ◽

2007 ◽

Vol 546-549 ◽

pp. 1467-1470

Author(s):

Shu Suo Li ◽

Chun Xiao Zhang ◽

Yong Wang Kang ◽

Ya Fang Han

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Hot Corrosion ◽

Base Alloy ◽

Rupture Life ◽

Stress Rupture ◽

Tensile Tests ◽

Stress Rupture Life ◽

Obvious Effect ◽

Resistance Tests

The effect of NiCr-CrAl coating on the microstructure, oxidation and corrosion resistance, as well as mechanical properties of Ni3Al base alloy IC6AE has been studied in the present investigation. NiCr-CrAl coating for alloy IC6AE was prepared by the powder pack cementation method. The oxidation resistance tests were carried out under the condition of 1050°C/100h, while the hot corrosion resistance tests were under 900°C/100h. The tensile tests at the room temperature and the stress rupture life tests under 1050°C/90Mpa have been also conducted. The experimental results showed that NiCr-CrAl as-coated specimens had excellent oxidation and hot corrosion resistance compared with the alloy IC6AE blank specimens, and NiCr-CrAl coating has no obvious effect on the mechanical properties of alloy IC6AE. It may be concluded that NiCr-CrAl coating is suitable for the alloy IC6AE.

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Effect of Long-Term Aging on the Microstructures and Stress Rupture Properties of a Ni-Based Single Crystal Superalloy at 980°C

Materials Science Forum ◽

10.4028/www.scientific.net/msf.788.560 ◽

2014 ◽

Vol 788 ◽

pp. 560-564 ◽

Cited By ~ 1

Author(s):

Jian Wei Xu ◽

Li Li Cui ◽

Hai Wen Wang

Keyword(s):

Single Crystal ◽

Rupture Life ◽

Interface Reaction ◽

Stress Rupture ◽

Stress Rupture Life ◽

Phase Coarsening ◽

Precipitated Phase ◽

Stress Rupture Properties ◽

Rupture Properties

The effect of aging time at 980°C on the microstructures and mechanic properties for a single crystal Ni-based superalloy was investigated in this paper. The results showed that γ’ size distribution portrayed a low growth rate and maintained well cubic during aging for 0~1000h at 980°C. However, γ’ phase was gradually coarsened directionally during the aging for 1000~2500h at 980°C, indicating that the γ’ phase coarsening was controlled by diffusion during aging for 0~1000h at 980°C. In addition, the γ’ phase coarsening was also susceptible to the interface reaction during aging for 1000~2500h at 980°C. Furthermore the precipitated phase was analyzed, and the results showed that only slightly Topologically Close-Packed (TCP) phase was precipitated after aging for 1500h at 980°C which indicates that the microstructures of alloy were stable during aging for up to 1500 hours. At the same time, stress rupture life decreased rapidly for 0~250h, but basically kept constant value when aged for 250~1500h, then decreased rapidly again aging for 1500~2000h.

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Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071326 ◽

1973 ◽

Vol 31 ◽

pp. 176-177

Author(s):

D. E. Fornwalt ◽

A. R. Geary ◽

B. H. Kear

Keyword(s):

Electron Microscope ◽

Grain Boundaries ◽

Volume Fraction ◽

Rupture Life ◽

Stress Rupture ◽

High Volume ◽

Precipitate Morphology ◽

Stress Rupture Life ◽

Nickel Base ◽

Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

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Effect of Microcast-X Fine Grain Casting on the Microstructure and Mechanical Properties of K492M Alloy at 760°C

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.549 ◽

2016 ◽

Vol 849 ◽

pp. 549-556

Author(s):

Pin Pin Hu ◽

Qi Dong Gai ◽

Qing Li ◽

Xin Tang

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Grain Size ◽

Rupture Life ◽

Stress Rupture ◽

Casting Alloy ◽

Stress Rupture Life ◽

Casting Technique ◽

Conventional Casting ◽

Fine Grain

The effect of Microcast-X fine grain casting on the microstructure and mechnical property K492M alloy at 760°C of was investigated. The results indicated that Microcast-X fine grain casting decreased grain size and dendrite space of γ′ phase and γ/γ′ eutectic. In addition, the element segregation decreased significantly compared to conventional casting technique. Also, the size and distribution of MC carbide were improved. By Microcast-X fine grain casting, the tensile strength increased from 934MPa of conventional casting alloy to 1089MPa and the elongation increased from 1.9% to 5.7%. In addition, the stress-rupture life increased from 28.8h of conventional casting alloy to 72.5h. And the fracture mechanism for the alloys by Microcast-X fine grain casting is trans-granular fracture toughness.

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Influence Mechanism of Silicon on Carbide Phase Precipitation of a Corrosion Resistance Nickel Based Superalloy

Materials ◽

10.3390/ma13040959 ◽

2020 ◽

Vol 13 (4) ◽

pp. 959 ◽

Cited By ~ 1

Author(s):

Tao Liu ◽

Mei Yang ◽

Fenfen Han ◽

Jiasheng Dong

Keyword(s):

Carbide Phase ◽

Silicon Content ◽

Rupture Life ◽

Stress Rupture ◽

Low Carbon ◽

Stress Rupture Life ◽

Corrosion Resistant ◽

Stress Rupture Properties ◽

Corrosion Resistant Alloy ◽

Rupture Properties

The effect of silicon on diffusion behavior of the carbide forming elements in Ni-Mo-Cr-Fe based corrosion-resistant alloy is studied by diffusion couple experiment. One group of diffusion couples are made of the alloy with a different silicon content, another group of diffusion couples are made of pure nickel and the alloy with different silicon content (0Si, 2Si). Two groups of alloys with same silicon content and different carbon content are also prepared, the microstructure of solution and aging state of these two groups alloys are analyzed, and their stress rupture properties are tested. The effect of silicon on the diffusion of alloy elements and the interaction effect of carbon and silicon on the microstructure and stress rupture properties of the alloy are analyzed. The mechanism of Si on the precipitation behavior of carbide phase in Ni-Mo-Cr-Fe corrosion resistant alloy is discussed. The results show that silicon can promote the diffusion of carbide forming elements and the formation of carbide. The precipitation behavior of the secondary phase is the result of the interaction effect of silicon and carbon, and is related to the thermal history of the alloy. Combined with the characteristic of primary carbides, it is confirmed that the precipitation of M12C type secondary carbide is caused by the relative lack of carbon element and the relative enrichment of carbide forming elements such as molybdenum. The stress rupture properties of two silicon-containing alloys with different carbon contents in solution and aging state are tested. The stress rupture life of low carbon alloy is lower compared with high carbon alloy at solution state, but after aging treatment, the stress rupture life of low carbon alloy is significantly improved, and higher than that of high carbon alloy. The main aim of this research is to reveal the influence mechanism of silicon on carbide phase precipitation of a Ni-Mo-Cr-Fe based corrosion-resistant superalloy, which provides theoretical basis and reference for later alloy design and engineering application.

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Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.849.570 ◽

2016 ◽

Vol 849 ◽

pp. 570-579

Author(s):

Qiang Huang ◽

Jin Xia Song ◽

Qing Li ◽

Wei Peng Ren ◽

Xin Guang Guan ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Cooling Rate ◽

Room Temperature ◽

Rupture Life ◽

Tensile Elongation ◽

Solution Treatment ◽

Stress Rupture ◽

Stress Rupture Life ◽

Microstructures And Mechanical Properties

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.

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