The Effects of Ni Content and Intermediate Annealing Condition on Recrystallization of Al-Fe-Ni-Si Alloy Fin Stocks

2016 ◽  
Vol 877 ◽  
pp. 166-171
Author(s):  
Kenta Suzuki ◽  
Daisuke Shimosaka ◽  
Tomohiro Sasaki ◽  
Yasuyuki Owada ◽  
Shuhei Kuroiwa ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Exchangers ◽  
Microstructural Analysis ◽  
Salt Bath ◽  
Grain Structure ◽  
Recrystallization Behavior ◽  
Intermediate Annealing ◽  
Annealing Conditions ◽  
Ni Content ◽  
Low Density Area

The effects of Ni content and intermediate annealing conditions on recrystallization behavior during brazing heat treatment of Al–Fe–Ni–Si alloys fin stocks of automotive heat exchangers were studied by means of microstructural analysis. Following brazing heat treatment, coarsening of recrystallized grain structure was observed in both 0.5% Ni and 1.0% Ni fin stocks, which were intermediately annealed in a salt bath. This coarsening was particularly marked in 1.0% Ni fin stocks. The results of the microstructural observations indicated that fine dispersoids were heterogeneously dispersed in 1.0% Ni fin stocks that were annealed at 550°C for 10 s in a salt bath. It was proposed that the preferential recovery and recrystallization during the brazing heat treatment in the low density area of the fine dispersoids contributed to the larger recrystallized gain structure. The coarse recrystallized grains obtained by controlling the salt bath annealing conditions are expected to contribute in improving the properties of Al–Fe–Ni–Si alloy fin stocks of automotive heat exchangers.

The Effect of Intermediate Annealing Condition on Recrystallization Behavior in Continuous Cast Al-Mn Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1251-1256
Author(s):  
Kenta Suzuki ◽  
Tomohiro Sasaki ◽  
Toshiya Anami
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Rapid Heating ◽  
Salt Bath ◽  
Grain Structure ◽  
Annealing Condition ◽  
Recrystallization Behavior ◽  
Intermediate Annealing ◽  
Continuous Cast

Favorable features such as finer particles and supersaturated solid solution are characterized in continuous casting. In this study, difference of recrystallization behavior was mainly evaluated on two intermediate annealing conditions in continuous cast Al-Mn alloy. One annealing condition was air furnace annealing which corresponds to batch type annealing and is conventionally used to anneal aluminum alloys. Another one was salt bath annealing which simulates CAL type annealing, which is characterized by shorter holding time with rapid heating and cooling. With consideration for application to fin stock in heat exchanger, heat treatment simulating brazing at 600°C was carried out on cold rolled sheets after respective intermediate annealing. After the brazing heat treatment, superior tensile strength and coarser grain structure were attractively obtained with the salt bath intermediate annealed fin. This tensile strength was correlated with much finer particles and more solid solution confirmed after the salt bath intermediate annealing. The coarser grain structure would be brought by changing in recovery and recrystallization behavior during brazing heat treatment.

scholarly journals Effects of Si and Zr addition on strength and recrystallization behavior of Al-Mn alloy fin stocks for automotive heat exchanger

2020 ◽  
Vol 326 ◽  
pp. 05006
Author(s):  
Daisuke Shimosaka ◽  
Mamoru Ueno
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Heat Exchanger ◽  
The Other ◽  
Grain Structure ◽  
Recrystallization Behavior ◽  
Intermediate Annealing ◽  
Zr Addition ◽  
Grain Structures ◽  
Alloy Heat

For an Al-Mn alloy heat exchanger fin stocks which continuous casting was simulated in, the effects of Si and Zr addition on strength and recrystallized grain structures after brazing heat treatment were investigated. As a result of tensile test, pre-brazed tensile strength was increased with increasing Si and Zr contents in the Al-Mn alloy. On the other hands, Zr addition have a small effect on post-brazed tensile strength regardless of Si contents. This was attributed the dissolution of Al3Zr or (Al,Si)3Zr precipitates during brazing heat treatment. Post-brazed grain structure were refined with increasing Si contents. Meanwhile, Zr addition led to larger post-brazed grain structures. It was found that Al3Zr or (Al,Si)3Zr precipitated during intermediate annealing played to major role in retarding recrystallization during brazing heat treatment.

scholarly journals Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Felix Clemens Ewald ◽  
Florian Brenne ◽  
Tobias Gustmann ◽  
Malte Vollmer ◽  
Philipp Krooß ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crack Formation ◽  
Microstructural Analysis ◽  
Tensile Load ◽  
Grain Structure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cyclic Heat Treatment ◽  
Powder Bed ◽  
Cyclic Heat

In order to overcome constraints related to crack formation during additive processing (laser powder bed fusion, L-BPF) of Fe-Mn-Al-Ni, the potential of high-temperature L-PBF processing was investigated in the present study. The effect of the process parameters on crack formation, grain structure, and phase distribution in the as-built condition, as well as in the course of cyclic heat treatment was examined by microstructural analysis. Optimized processing parameters were applied to fabricate cylindrical samples featuring a crack-free and columnar grained microstructure. In the course of cyclic heat treatment, abnormal grain growth (AGG) sets in, eventually promoting the evolution of a bamboo like microstructure. Testing under tensile load revealed a well-defined stress plateau and reversible strains of up to 4%.

scholarly journals Microstructure and Mechanical Characterization of Austempered AISI 1018 Steel

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Muideen Bodude ◽  
Oluwole D Adigun ◽  
Ahmed Ibrahim
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Energy ◽  
Microstructural Analysis ◽  
Salt Bath ◽  
Isothermal Transformation ◽  
Critical Conditions ◽  
Average Value ◽  
Extreme Load ◽  
Bainite Microstructure

AISI 1018 mild steels are widely used for engineering applications in machine components and for structural purposes. These materials suffer mechanical damages especially when used under critical conditions of extreme load. In this study, the effect of austempering heat-treatment on the hardness, tensile strength, impact energy and the microstructure of AISI 1018 steels were evaluated. The steel specimens were subjected to austempering heat-treatment by austenitizing at a temperature of 830°C, maintained at this temperature for a period of 1 hour 30 minutes, before rapidly cooled down in a NaNO3 salt bath maintained at 300°C for isothermal transformation for a further 50 minutes before finally cooled down to room temperature. Microstructural analysis using Scanning Electron Microscope (SEM) shows transformation from ferrite/pearlite to bainite microstructure. The tensile strengths of the specimen increased from 400 MPa to 500 Mpa; hardness increased from an average value of 140Rc to 162Rc; while impact energy increased from 15.6 Joule to 30.6 Joule by the austempering heat-treatment. Keywords—Austempering, hardness, tensile strength, impact energy, microstructure

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

TEMPERATURE EFFECT ON MICROSTRUCTURAL ANALYSIS OF STEEL DURING HEAT TREATMENT

2020 ◽  
Author(s):  
SAMUEL BRITO ◽  
RODOLFO SOBRAL ◽  
Luiz Carlos Sacramento ◽  
Marcos Paulo de Souza Junior
Keyword(s):  
Heat Treatment ◽  
Temperature Effect ◽  
Microstructural Analysis

Quantitative Microstructural Analysis of a Ni-based Superalloy After Different Heat Treatments

2020 ◽  
Vol 70 (12) ◽  
pp. 4519-4524
Keyword(s):  
Heat Treatment ◽  
Internal Structure ◽  
Microstructural Analysis ◽  
Temperature Treatment ◽  
Heat Treatments ◽  
Metal Melts ◽  
Metallic Inclusions ◽  
Undercooled Melt ◽  
Super Alloy

The efficiency of time-temperature treatment (T-TT) on metal melts can be microstructurally analysed through their degree of purity in non-metallic inclusions. In the case of the Ni-based super alloy under discussion (MSRR 7045) the heat treatment was the undercooling consequences both on the durability of the casting environment (ingots-refractories) and on the internal structure of the metal (porosity, microstructural isotropy). Keywords: time-temperature treatment, undercooled melt, non-metallic inclusions, purity, microstructural isotropy

The effects of preparation and some physico-chemical parameters on the properties of styrene catalyst - based on iron(III) oxide.

1983 ◽  
Vol 48 (2) ◽  
pp. 421-438 ◽  
Author(s):  
Milan Pospíšil ◽  
Jiří Spěváček ◽  
Jindřich Kryška
Keyword(s):  
Heat Treatment ◽  
Discontinuous Precipitation ◽  
Microstructural Analysis ◽  
Sulfate Solution ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Additional Thermal Treatment ◽  
Genetic Sequences ◽  
Dehydrogenation Of Ethylbenzene ◽  
Thermal Stability Of

Hydrated iron(III) oxides were obtained by discontinuous precipitation of an iron(II) sulfate solution with aqueous ammonium - saturated with carbon dioxide to different CO2/NH3 ratios. An additional thermal treatment of these oxides, under different conditions, provided genetic sequences of intermediates and their final products - catalysts on a Fe2O3/K2O basis, with different promoters. The catalysts were studied by means of the microstructural; analysis, thermogravimetry, DTA, IR spectroscopy and further tested by the dehydrogenation of ethylbenzene to styrene. It was observed that by changing the CO2/NH3 ratio in the precipitation of the initial solutions one can influence some of the properties, as well as, the morphology and thermal stability of the initial intermediates of the preparation of the catalysts. The above mentioned properties become practically unified with the increasing number of the heat treatment operations, with all the investigated catalysts - with the exception of the catalysts' behaviour during their reduction with hydrogen. The presence of iron oxides in various valency states and the different phase composition of the catalysts during their reduction affect the final activity and selectivity of the catalyst in the reaction under the study.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

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