scholarly journals Effect of Dissolution of η′ Precipitates on Mechanical Properties of A7075-T6 Alloy

2022 ◽  
Vol 60 (1) ◽  
pp. 83-93
Author(s):  
Young-We Kim ◽  
Yong-Hee Jo ◽  
Yun-Soo Lee ◽  
Hyoung-Wook Kim ◽  
Je-In Lee
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Solution Treatment ◽  
Aluminum Matrix ◽  
Natural Aging ◽  
Aging Treatment ◽  
Nucleation Site ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Bake Hardening

The effects of dissolution of the η′ phase by solution treatment on the mechanical properties of A7075-T6 alloy were investigated. Immediately after solution treatment of the T6 sheet at 450 oC or higher, elongation significantly increased and dissolution of the η′ phase occurred. η′ is the main hardening phase. After natural-aging, GPI, which is coherent with the aluminum matrix, was formed and strength increased. When bake hardening after natural-aging was performed, the yield strength slightly increased due to partial dissolution of the GPI and re-precipitation of the η′ phase. In contrast, after solution treatment at 400 oC, there was less elongation increase due to the precipitation of the coarse η phase at grain boundaries and low dissolution of the η′ phase. In addition, when bake hardening after natural-aging was performed, the yield strength decreased due to insufficient GPI, which is the nucleation site of the η′ phase. To promote reprecipitation of the η′ phase, the solution treatment temperature was set to a level that would increase solubility. As a result, the yield strength was significantly increased through re-precipitation of a large number of fine and uniform η′ phase. In addition, to increase the effect of dissolution, a pre-aging treatment was introduced and the bake hardenability can be improved after dissolution.

scholarly journals Correlation between Solution Treatment Temperature, MicroStructure, and Yield Strength of Forged Ti-17 Alloys

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Yoko Yamabe-Mitarai ◽  
Syuji Kuroda ◽  
Norie Motohashi ◽  
Takanobu Hiroto ◽  
Akira Ishida ◽  
...  
Keyword(s):  
Yield Strength ◽  
Room Temperature ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Jet Engines ◽  
Solution Treated ◽  
Α Phase

The Ti compressor disks of aviation jet engines are produced by forging. Their microstructure, which depends on the forging conditions, strongly affects their mechanical properties. In this study, changes in the microstructure of Ti-17 alloy as a result of different solution-treatment (ST) temperatures and the related tensile yield strengths were investigated to elucidate the correlation between the ST temperature, microstructure, and yield strength. Ti-17 alloys ingots were isothermally forged at 800 °C and solution-treated at 750, 800, and 850 °C. The microstructure and yield strength were investigated for samples subjected to different ST temperatures. The primary α phase formed during the ST, and the secondary α phase formed during the aging treatment at 620 °C. The yield strength increased with increasing volume fraction of the primary α phase and increased further upon formation of the secondary α phase during the tensile test at room temperature. The correlation of the primary and secondary α phases with yield strength was clarified for tensile properties at room temperature, 450, and 600 °C. An equation to predict the yield strength was constructed using the volume fraction of the primary and secondary α phases.

Effect of Boron Addition on Microstructure and Mechanical Properties of AZ84 Mg Alloy

2016 ◽  
Vol 879 ◽  
pp. 653-658
Author(s):  
Ju Hyun Won ◽  
Seok Hong Min ◽  
Tae Kwon Ha
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Mg Alloy ◽  
Solution Treatment Temperature ◽  
Solid Solution Treatment ◽  
Microstructure And Mechanical Properties ◽  
Peak Aging ◽  
Aging Kinetics

Effect of B addition on the microstructure and mechanical properties of AZ84 Mg alloy was investigated in this study. Through calculation of phase equilibria of AZ84 Mg alloy, carried out by using FactSage® and FTLite database, solution treatment temperature was decided as temperature of 330oC, where supersaturated solid solution can be obtained. Solid solution treatment of AZ84 Mg alloy was successfully conducted at 330oC and supersaturated microstructure with all almost all phases resolved into matrix was obtained. After solution treatment, hot rolling was successfully conducted by reduction of 60%. Compression and tension tests were carried out at room temperature on the samples in as-cast, solution treated, hot-rolled and subsequently recrystallized states. After solid solution treatment, each alloy was soaked at temperatures of 180 and 200oC for time intervals from 1 min to 48 hrs and hardness of each condition was measured by micro-Vickers method. Peak aging conditions were deduced as at the temperature of 200 oC for 10 hrs for ZA84 Mg alloy. By addition of boron, aging kinetics was expedited and strength was enhanced.

scholarly journals Recovery of Microstructure and Mechanical Properties of Service Run GTD-111 DS Buckets

1999 ◽  
Author(s):  
N. S. Cheruvu ◽  
V. P. Swaminathan ◽  
C. D. Kinney
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Solution Treatment ◽  
Partial Solution ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
High Temperature Solution ◽  
Microstructure And Properties ◽  
Microstructure And Mechanical Properties ◽  
Temperature Solution

Degradation of microstructure and mechanical properties of a service run GTD-111 DS blade was evaluated. The blade was coated with a CoCrAlY coating (GT-29) and had operated on a GE Model MS 5002 engine for 54,850 hours. To recover the microstructure of the degraded blade, the effect of solution treatment temperature on the microstructure and properties was evaluated. The blanks removed from the airfoil tip section were given a commonly used partial solution treatment 2050°F (1120°C) for GTD-111 and a high temperature solution treatment 2175°F (1190°C) prior to the partial solution and aging treatments. Microstructure and creep test results of these heat treated specimens revealed that the high temperature solution treatment was necessary to recover the microstructure and properties of in-service degraded GTD-111 DS buckets.

Effects of Natural Ageing on T6 Heat Treated Rheocasts of 319S Aluminum Alloy

2016 ◽  
Vol 256 ◽  
pp. 58-62 ◽  
Author(s):  
Kang Du ◽  
Qiang Zhu ◽  
Da Quan Li
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloys ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Artificial Ageing ◽  
Natural Ageing ◽  
T6 Heat Treatment ◽  
Semi Solid

T6 heat treatment is an effective method to improve the comprehensive properties of Al-Si-Cu-Mg series aluminium alloys. Solution treatment temperature and time, quench process and media, as well as artificial ageing temperature and time are the key factors to determine mechanical properties. Besides these factors, natural ageing, i.e. the holding time between quenching and the starting of artificial treatment at ambient temperature was observed to be significant affect mechanical properties of the aluminium alloys. This effect on semi solid processed aluminium alloys was lack of investigations as the semi solid process produces T6 treatable and weldable components. The present paper focuses on the change regularity of hardness and precipitate behaviour of semi-solid 319S aluminium alloy under different natural ageing (NA) treatment additional to standard T6. Density and morphology of hardening precipitates are analysed using TEM, and the influence mechanism of NA during T6 heat treatment will be discussed. The results show that NA has a positive influence on mechanical properties of the rheo-cast 319S alloy.

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 Heat Treatment on the Microstructural Characteristics of IN738 Turbine Blade

2011 ◽  
Vol 695 ◽  
pp. 405-408 ◽  
Author(s):  
Ho Seob Yun ◽  
Joon Sik Park ◽  
Seong Uk An ◽  
Jeong Min Kim
Keyword(s):  
Solid Solution ◽  
Size Distribution ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Hardness Test ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Gamma Prime ◽  
Average Size ◽  
Single Size

It was observed that both primary and secondary gamma prime precipitates were more significantly influenced by the solid solution treatment temperature as compared to the following cooling rate. Single and duplex size precipitate distribution with different average size could be obtained through the appropriate solid solution and aging treatment. Micro-hardness test result indicated that single size distribution of gamma prime precipitates provides higher hardness than duplex size distribution.

Influence of Yttrium and Heat Treatment on Microstructure and Mechanical Properties of AM60 Alloy

2011 ◽  
Vol 194-196 ◽  
pp. 1319-1325
Author(s):  
Zheng Tian ◽  
Zhan Yi Cao ◽  
Jian Meng
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Yield Strength ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Hardness Measurement ◽  
X Ray ◽  
Solid Solution Treatment ◽  
Yttrium Addition

The effect of yttrium addition and heat treatment on the mechanical properties and microstructure of AM60 magnesium alloy have been investigated using X-ray phase analysis, microstructure investigation, tensile test, hardness measurement and fracture surfaces analysis. The results showed that the mechanical properties of the alloys were obviously improved with the addition of yttrium no more than 1.0%. The reinforcement of the alloys resulted from the appearance of Al2Y phase. After solid-solution treatment (T4), the Mg17Al12 phase almost dissolved in Mg matrix, but the rare earth compounds Al2Y phase was rather stable. The ultimate tensile strength σb was improved, but the yield strength σ0.2 and elongation δ were only slightly changed. After solid-solution + aging treatment (T6), the Mg17Al12 phase precipitated again and their morphology was changed. The yield strength σ0.2 was improved.

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