scholarly journals Combined Effects of Optimized Heat Treatment and Nickel Coating for the Improvement of Interfacial Bonding in Aluminum–Iron Alloys Hybrid Structures

2021 ◽  
Vol 11 (4) ◽  
pp. 1501
Author(s):  
Gihoon Moon ◽  
Eunkyung Lee
Keyword(s):  
Heat Treatment ◽  
Chemical Bonding ◽  
Nickel Coating ◽  
Microstructural Analysis ◽  
Solution Treatment ◽  
Hybrid Structures ◽  
Treatment Conditions ◽  
Precipitation Characteristics ◽  
Aluminum Iron ◽  
Al Matrix

The effects of nickel coating and heat treatment on the interfacial bonds of aluminum–iron (Al/Fe) alloys hybrid structures were investigated using microstructural analysis. The application of a nickel coating successfully suppressed the formation of defects such as gaps and oxide scale, improving the physical bonding of the interface. Optimizing the heat treatment conditions generated superior chemical bonding at the interface and facilitated the formation of a nickel-bearing phase in the Al matrix. Also, the types of nickel-bearing phase were influenced by solution treatment and proximity to the interface. By analyzing the isopleth phase diagram of the aluminum system for the ranges of nickel present in the Al, it was confirmed that the Ni:Cu ratio affected the precipitation characteristics of the system. However, when heated under conditions that were optimized for chemical bonding, the Al matrix decreased by approximately 40% (from 100 HV to 60 HV), due to grain growth. The effect of artificial aging increased the hardness of the Al matrix away from the interface by 35% (from 63 HV to 90 HV). On the other hand, this did not occur in the Al matrix near the interface. These results indicate that the nickel that diffused into the Al matrix interfered with the precipitation hardening effect.

Long-Term Gamma Prime Phase Stability after Various Heat Treatment Conditions with Temperature Dropping during Solution Treatment in Cast Nickel Base Superalloy, Grade Inconel-738

2017 ◽  
Vol 891 ◽  
pp. 420-425
Author(s):  
Sureerat Polsilapa ◽  
Aimamorn Promboopha ◽  
Panyawat Wangyao
Keyword(s):  
Heat Treatment ◽  
Turbine Blades ◽  
Solution Treatment ◽  
Nickel Base Superalloy ◽  
Gamma Prime ◽  
Nickel Based Superalloy ◽  
Treatment Conditions ◽  
Nickel Base ◽  
Base Superalloy

Cast nickel based superalloy, Grade Inconel 738, is a material for turbine blades. Its rejuvenation heat treatment usually consist of solution treatment condition with temperature range of 1125-1205 oC for 2-6 hours. Then it is following with double aging process including primary aging at 1055oC for 1 hour and secondary aging at 845oC for 24 hours. However, the various selected temperature dropping program were performed during solution treatment to simulate the possible error of heating furnace. The maximum number of temperature dropping during solution treatment is varied from 1-3 times From all obtained results, the various temperature dropping during solution treatment conditions showed extremely the significant effect on the final rejuvenated microstructures and long-term gamma prime stability after heating at temperature of 900oC for 200 hours.

scholarly journals Microstructure and Mechanical Property of Al6Si2Cu Alloy Subjected to Double-Solution Heat Treatment

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Seongbin An ◽  
Minsuk Kim ◽  
Chaeeul Huh ◽  
Chungseok Kim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Intermetallic Phase ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Solution Temperature ◽  
Eutectic Si ◽  
Equilibrium Phases ◽  
Al Matrix

This study aims to develop the mechanical properties of the Al6Si2Cu aluminum alloy through the double-solution treatment. In addition to the Al matrix, large amounts of coarse eutectic Si, Al2Cu intermetallic, and Fe-rich phases were generated through thermo-calc simulation in agreement with the equilibrium phases. The eutectic Si phase is fragmented and spheroidized by the solution treatment as the heat treatment temperature and time increase. The Al2Cu intermetallic phase is dissolved into the Al matrix, resulting in an increase in both strength and elongation. The second-step solution temperature at 525 °C should be an optimum condition for enhancing the mechanical properties of the Al6Si2Cu aluminum alloy.

Improvement in Creep Strength of Heat-Resistant Ferritic Steel Precipitation-Strengthened by Intermetallic Compound

2007 ◽  
Vol 539-543 ◽  
pp. 2994-2999
Author(s):  
Yoshiaki Toda ◽  
Hideaki Kushima ◽  
Kazuhiro Kimura ◽  
Fujio Abe
Keyword(s):  
Heat Treatment ◽  
Creep Strength ◽  
Ferritic Steel ◽  
Fine Particles ◽  
Volume Fraction ◽  
Nickel Content ◽  
Solution Treatment ◽  
Martensite Phase ◽  
Treatment Conditions ◽  
Quenched Steel

The effects of nickel content and heat treatment conditions on the creep strength of precipitation-strengthened 15Cr ferritic steel were investigated. The creep strength of the 15Cr ferritic steel was drastically improved by solution treatment and water quenching. However, over the long term, the detrimental effect of nickel on the creep strength was pronounced for water-quenched steels. The volume fraction of martensite phase increased with increased nickel content in both the furnace-cooled and water-quenched steels. The volume fraction of martensite phase in the water-quenched steel was smaller than that in the furnace-cooled type, even for the same nickel content. Fine particles, smaller than 500 nm, were precipitated homogeneously within the ferrite phase of the water-quenched steel. On the other hand, coarse block-like particles 1 $m in size were precipitated sparsely within the martensite phase. The creep strength of the steels decreased with increased volume fraction of the martensite phase caused by furnace cooling and nickel addition. The lower creep strength and microstructural stability of the martensite phase is attributable to less precipitation strengthening. To enable this steel to be put to practical use, it will be necessary to suppress the formation of the martensite phase caused by addition of nickel by optimizing the chemical composition and heat treatment conditions.

scholarly journals Effect of Heat Treatments on the Microstructural Evolution of a Single Crystal High-Entropy Superalloy

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1600 ◽  
Author(s):  
Takuma Saito ◽  
Yung-Ta Chen ◽  
Yuji Takata ◽  
Kyoko Kawagishi ◽  
Wei-Che Hsu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Microstructural Evolution ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Cast Sample ◽  
High Entropy ◽  
Treatment Conditions ◽  
Interdendrite Region ◽  
Aging Conditions

The effect of solution heat treatment as well as primary and secondary aging treatment conditions on the microstructural evolution of a high-entropy superalloy was investigated. The as-cast sample shows coarsened γ′ precipitates and other extra phases at interdendrite region due to microsegregation. This microsegregation makes γ′ solvus unclear and decreases the solidus. After conducting the solution treatment determined in this study, primary aging conditions showing an aligned cubic γ′ phase at 1050 °C for 4 h and random spherical γ′ precipitates at 950 °C for 20 h in similar size were found. By using both samples, secondary aging conditions showing coarsened secondary γ′ precipitates and γ particles inside the γ′ precipitates at 800 °C for 20 h and fine secondary γ′ precipitates at 850 and 870 °C for 20 h were found.

scholarly journals Friction-Stir Welding of a Wrought Al-Si-Mg Alloy in As-Fabricated and Heat-Treatment States

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 861
Author(s):  
Chunxia Wang ◽  
Hongbo Cui ◽  
Xin Tang ◽  
Kezhun He
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Solution Treatment ◽  
Base Material ◽  
Welding Process ◽  
Age Hardening ◽  
Weld Strength ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Al Matrix

A wrought Al-11.3Si-0.6Mg alloy under hot extrusion (T1), solution treatment (T4), and solution treatment + artificial aging (T6) states were friction stir welded at welding speed of 100 mm/min and rotation rate of 800 rpm. The effect of prior heat-treatment on the microstructure and mechanical properties of the welds were investigated. The results show that the microstructures of the nugget zones have little dependence on the initial states of the base material. In the nugget zones, complete recrystallized structures with equaxied grains in the Al matrix were formed under all conditions. The Si particles in the nugget zones are almost unchanged compared with those of their base materials (BMs) in the three states. In contrast, the joint efficiency of the obtained welds was very sensitive to the initial material condition. The joint efficiency under the T1 state is more than 90% due to the fact that the microstructure is almost unchanged, except for the slight coarsening of the Al matrix grains and some of the Mg2Si phases during the friction stir welding process. However, the joint efficiency in the T4 and T6 conditions is only 77.22% and 62.03%, respectively. The relatively low weld strength in the T4 and T6 conditions is due to the elimination of the solid solution strengthening and age hardening effects during friction stir welding. The hardness distributions along the cross section of joints are all W-shaped under T1, T4, and T6 conditions.

Effect of Solution Heat Treatment and Additives on the Microstructure of Al – Si (A413.1) Automotive Alloys

2004 ◽  
Vol 467-470 ◽  
pp. 399-406 ◽  
Author(s):  
M.A. Moustafa ◽  
F.H. Samuel ◽  
H.W. Doty
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Microstructural Analysis ◽  
Solution Treatment ◽  
Microstructural Characteristics ◽  
Unmodified Alloy ◽  
Heat Treated ◽  
Cast Condition

A study was carried out to determine the role of additives such as Mg and Cu on the microstructural characteristics of grain refined, Sr-modified eutectic A413.1 alloy (Al-11.7% Si) during solution heat treatment. For comparison purposes, some of the alloys were also studied in the non-modified condition. The alloys were cast in a steel permanent mold preheated at 425 °C that provided a microstructure with an average dendrite arm spacing (DAS) of ~ 22 µm. Castings were solution heat treated at 500 ± 2 °C for time up 24 h, followed by quenching in warm water (at 60 °C). Microstructural analysis of the as-cast and heat-treated castings was carried out using optical microscopy in conjunction with image analysis. Phase identifications were done using the electron probe microanalysis (EPMA) technique. In the as-cast condition, the addition of 0.42 wt% Mg to the unmodified alloy produced relatively large Si particles compared to the base A413.1 alloy. The Si particle size remained more or less the same with increase in solution treatment time and Mg level. Both Mg2Si and Al2Cu phases were observed to dissolve almost completely after 8 h solution time, while the Al5Cu2Mg8Si6 phase was found to persist even after 24 h.

Effect of Post Weld Heat Treatment on Mechanical Properties and Microstructure of Nickel Based Super Alloy Welds

2012 ◽  
Vol 585 ◽  
pp. 435-439
Author(s):  
M. Agilan ◽  
T. Venkateswaran ◽  
D. Sivakumar ◽  
Bhanu Pant
Keyword(s):  
Heat Treatment ◽  
Solution Treatment ◽  
Microscopic Analysis ◽  
Hardness Test ◽  
Post Weld Heat Treatment ◽  
Gas Tungsten Arc ◽  
Treatment Conditions ◽  
Direct Aging ◽  
Super Alloy ◽  
Weld Heat

In the present paper, Haynes 214 plate of 7mm thick was welded by Gas tungsten arc welding (GTAW) in two passes. The welded plates were subjected to post-weld heat treatment such as direct aging (DA) and solution treatment + aging (STA). The aging cycle was optimized using hardness by generating isothermal aging curve. The weld tensile properties, hardness test, microscopic analysis and fractographic studies were carried out in as-welded condition and at two different post-weld heat treatment conditions. The results show a significant increase in both yield and tensile strength after post weld heat treatment.

Optimization of Heat Treatment Conditions of Magnesium Cast Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1488-1493 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Tomasz Tański ◽  
Jacek Trzaska
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Physical And Mechanical Properties ◽  
Salt Bath ◽  
Heating Time ◽  
Treatment Conditions ◽  
Casting Cycle ◽  
Crucible Furnace ◽  
Cast Magnesium

In this paper there are presented results of the optimization of heat treatment conditions, which are temperature and heating time during solution heat treatment or ageing as well the cooling rate after solution treatment for MCMgAl12Zn1, MCMgAl9Zn1, MCMgAl6Zn1, MCMgAl3Zn1 cast magnesium alloys. A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10°C, suitable for the manufactured material. The heat treatment involve the solution heat treatment and cooling in different cooling mediums as well water, air and furnace. The improvement of the manufacturing technique and chemical composition as well as of heat treatment and cooling methods leads to the development of a material designing process for the optimal physical and mechanical properties of a new developed alloy.

Investigation of the Optimal Heat Treatment of As-Cast Al-5.7Si-2Cu-0.3Mg Aluminium Alloys

2021 ◽  
Vol 105 ◽  
pp. 48-58
Author(s):  
M.A. Abdelgnei ◽  
M.Z. Omar ◽  
M.J. Ghazali ◽  
M.N. Mohammed
Keyword(s):  
Heat Treatment ◽  
Aluminium Alloys ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Hot Water ◽  
High Concentration ◽  
Hardness Tester ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Optimum Heat

The aim of this work is to investigate the optimum heat treatment for Al-5.7Si-2Cu-0.3Mg aluminium alloys and study its effect on microstructure, phase transformations, and hardness. The test specimens were taken from the as-received alloy. Solution treatment was performed at 485°C and 500°C under various solution treatment times for 4, 8, 10, and 12h, and the samples were then hot water quenched at 60°C, followed by aged hardening at 150°C, 170°C and 190°C for 2,6,10, and 14h, and subsequently air-cooled. The hardness of the Al-5.7%Si-2Cu%-0.3%Mg alloys were determined using a Rockwell hardness tester. Scanning electron microscopy (SEM) and optical microscopy (OM) were used to determine the microstructure of the samples, while X-ray diffraction (XRD) was used to identify the phase compositions. The resulting microstructures and hardness values were compared to the corresponding as-cast samples. It can be seen that the solution treatment at 485°C for 12 h and aging at 190°C for 10 h are the optimum T6 heat treatment conditions that would result in hardening precipitates over the as-cast alloy. OM and SEM morphologies show significant microstructure evaluation of improved distribution of the Si particles. After T6 treatment, the morphology of Si particles in the as-cast Al-5.7Si-2Cu-0.3Mg alloy changes from long and coarse plate-like grains to fine spherical shaped grain. The XRD plots confirmed the relatively high concentration of Al, Si, and Al2Cu in the heat treated Al-5.7%Si-2Cu%-0.3%Mg alloy relative to that of the as-cast alloy. The hardness of the T6 alloy also increased.

Effect of Solution Treatment on Ageing Behaviour of Al-Mg-Si-Sn Alloy

2021 ◽  
Vol 39 ◽  
pp. 1-8
Author(s):  
Monoj Baruah ◽  
Anil Borah
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Cast Alloy ◽  
Ageing Time ◽  
Microstructural Analysis ◽  
Solution Treatment ◽  
Intermetallic Phases ◽  
Peak Hardness ◽  
Artificial Ageing ◽  
Natural Ageing

In this study both natural ageing (NA) and artificial ageing (AA) behaviour of Al-Mg-Si aluminium alloy having trace addition of 0.04 wt.% Sn (Tin) was studied at different solution heat treatment (SHT) temperature and time, ageing time and temperatures. Microstructural analysis was performed to identify the intermetallic phases. It was observed that peak NA hardness strongly depends on the SHT temperature and time. SHT at 530 for 0.5 hour, slows down the peak NA hardness attaining time of the alloy to a maximum of 5 days. But as the SHT time increases to 3.5 hours, the peak NA hardness attaining time reduced to 1 day. Alloy SHT at 530 for 1 hour attain a maximum peak hardness of HRB 24 during 3 days of NA. Artificial ageing improved the hardness of the NA alloy to a maximum of HRB 41 during 12 hours of ageing at 190 . The overall hardness of Al-Mg-Si-Sn as-cast alloy increases by 32 % during ageing process.

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