Variation of Microstructure and Properties of Re-7075 Al Alloy after Homogenizing Annealing

2012 ◽  
Vol 463-464 ◽  
pp. 198-202
Author(s):  
Ju Guo Zhang ◽  
Hong Bin Zhu
Keyword(s):  
Volume Fraction ◽  
Optical Microscope ◽  
Primary Phase ◽  
Dendritic Segregation ◽  
Al Alloy ◽  
Second Phase ◽  
Microstructure And Properties ◽  
Analytical Instruments ◽  
Homogenizing Annealing ◽  
7075 Al Alloy

The variation of microstructure and properties of RE-7075 Al alloy after homogenizing annealing were studied by some modern analytical instruments which including OM(optical microscope),SEM(scanning electron microscopy),EDS(energy dispersive spectroscopy ), Brinell hardness and conductivity meter of SIGMASCOPE SMP10 type in this experiment. The results shows that the alloy′s microstructure was uniform ,reduced the volume fraction of second phase,increased supersaturation of matrix and eliminated gradually dendritic segregation in homogenizing annealing state. The primary phase of matrix microstructure contain α(Al),T(Al2Mg3Zn3) and grain boundary microstructure include α(Al),Al2Cu,AlCuMg4La4 after homogenizing annealing.Compared with as cast condition,the conductivity and the hardness reduced after homogenizing annealing.

Research on Properties of RE-7075 Al Alloy′s Hot Rolled

2012 ◽  
Vol 430-432 ◽  
pp. 574-577
Author(s):  
Jian Hua Zhong ◽  
Hong Bin Zhu ◽  
Kai Feng ◽  
Yin Ping Xiao
Keyword(s):  
Rapid Development ◽  
Rolling Process ◽  
Optical Microscope ◽  
Al Alloy ◽  
Rolled Sheet ◽  
Scanning Calorimetry ◽  
Burning Temperature ◽  
Analytical Instruments ◽  
7075 Al Alloy ◽  
Hot Rolled

The RE-7075 Al alloy′s hot rolled sheet was studied in this experiment.The microstructure,over-burning temperature,fracture surface and phase were analyzed by modern materials analytical instruments which include OM(optical microscope),DSC(differential scanning calorimetry), SEM(scanning electron microscope) and XRD(X-ray diffraction),respectively. The results show that there are needle-like or rod-like grains in the SL direction and the fibrous or streamlined grains in the LT direction of hot rolled sheet′s microstructure;The microstructure takes place the phenomenon of over-burning when rolling temperature beyond 480°C; These sheets manifest mainly brittle fracture under the tensile stress; The primary phase of microstructure contain α(Al)、AlLa4、Al2Zn3、AlMgZnCuLa、LaMgZn、AlMg4Zn11 . In recent years,people continued to study the rare earth (RE) and add the RE to the conventional aluminum alloy.So the RE became a hot research because it can improve the properties of materials. The RE-7075 Al alloy is one of the categories and can be widely used as the structural materials of aerospace and weapons industry.With aerospace and the war industry enterprise rapid development in our country, the quantity demand is getting bigger and bigger[1-2].Therefore,it is urgent for us to study a high strength-toughness aluminum alloy material.The aim of RE-7075 Al alloy′s hot rolled sheet was researched in this experiment.The microstructure, over-burning temperature,the fracture mode and phase composition of the sheet were indepth analysised under the rolling process. So these can provide a theoretical basis of the hot rolling process development of science.

Variation of Microstructure and Mechanical Properties of ZW61 Magnesium Alloy Solidified under Different Pressures

2022 ◽  
Vol 327 ◽  
pp. 3-10
Author(s):  
Shu Sen Wu ◽  
Xiao Gang Fang ◽  
Shu Lin Lü ◽  
Long Fei Liu ◽  
Wei Guo
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Volume Fraction ◽  
Applied Pressure ◽  
Second Phase ◽  
Cast State ◽  
Microstructure And Properties ◽  
Microstructure Refinement ◽  
Porosity Reduction ◽  
Average Grain Size

There is little datum related to microstructure and properties of Mg alloys squeeze-casted with pressure over 200 MPa. In this study, the microstructure and properties of Mg-6Zn-1.4Y (ZW61) alloy solidified under 100MPa to 800MPa were investigated. The results show that a remarkable microstructure refinement and porosity reduction can be reached through solidification under high pressure. The average grain size and the volume fraction of second phase, i.e. quasicrystal I-phase, decrease continuously with the increase of applied pressure. The tensile properties, especially elongation, are obvious enhanced because of the microstructure refinement and castings densification under high pressure. The ultimate tensile strength and elongation of ZW61 alloy in as-cast state are 243 MPa and 18.7% when the applied pressure is 800 MPa, which are increased by 35% and 118% respectively, compared with that of the gravity castings.

Effect of Solution Treatment Temperature on Microstructure and Mechanical Properties of Al-5.1Zn-2Mg-0.1Ti (wt. %) Produced by Squeeze Casting

2018 ◽  
Vol 939 ◽  
pp. 38-45 ◽  
Author(s):  
Risly Wijanarko ◽  
Irene Angela ◽  
Bondan Tiara Sofyan
Keyword(s):  
Squeeze Casting ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Ageing Process ◽  
Al Alloy ◽  
Second Phase ◽  
Solution Treatment Temperature ◽  
Phase Volume Fraction ◽  
Ti Addition

Al 7xxx alloy is a heat treatable Al alloy with superior strength. Solution treatment in precipitation hardening sequence of the alloy has an important role to dissolve second phases and bring vacancies out to form precipitates in the ageing process. Another strengthening can be done by Ti addition as grain refiner. As cast alloy by squeeze casting was homogenized at 400 °C for 4 h. Solution treatment was conducted at 220, 420, and 490 °C, followed by rapid quenching. Subsequent ageing was conducted at 130 °C for 48 h. Characterization was performed by optical microscope, SEM-EDS (Scanning Electron Microscopy – Energy Dispersive Spectroscopy), Rockwell hardness testing, XRD (X-Ray Diffraction), and STA (Simultaneous Thermal Analysis). Ti added alloy showed rounder grains, lower hardness, and more reduction in second phase volume fraction along with increasing solution treatment temperature than those in alloys without Ti addition. Otherwise, the alloy final hardness was increasing and higher after the ageing process due to higher second phase dissolution which leads to more precipitates formed.

Homogeneous Al-Ti and Al-Ti-Si Thin Alloy Films

1985 ◽  
Vol 54 ◽  
Author(s):  
Albertus G. Dirks ◽  
Tien Tien ◽  
Janet M. Towner
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Electrical Resistivity ◽  
Phase Formation ◽  
Alloy Composition ◽  
Al Alloy ◽  
Second Phase ◽  
Alloy Films ◽  
Microstructure And Properties

ABSTRACTThe microstructure and properties of thin films depends strongly upon the alloy composition. A study was made of the metallurgical aspects of homogeneous Al alloy films, particularly the binary Al-Ti and the ternary Al-Ti-Si systems. Electrical resistivity, grain size morphology, second phase formation and electromigration have been studied as a function of the alloy composition and its heat treatment.

scholarly journals Effect of cooling rate on microstructure of B2-NiSc intermetallics

2019 ◽  
Vol 39 (3) ◽  
pp. 236-242
Author(s):  
Zhipeng Yuan ◽  
Hao Chen ◽  
Hongbao Cui ◽  
Yatao Chang ◽  
Xuefeng Guo
Keyword(s):  
Thin Plate ◽  
Volume Fraction ◽  
Solidification Rate ◽  
Centrifugal Casting ◽  
Critical Dimension ◽  
Eutectic Structure ◽  
Primary Phase ◽  
Solidification Structure ◽  
Second Phase ◽  
Lamellar Eutectic Structure

Ni-50at%Sc alloy was prepared by centrifugal casting method. Volume fraction, the actual content of B2-NiSc and second phase Ni2Sc in alloy were analyzed with an Image-Pro Plus software. The cooling rates for the solidified thin plate with thickness of 2.65mm, 1.2mm, 0.75mm and 0.35 mm are 1164, 2570, 4112 and 8811 K·s1, respectively. It is found that d=0.5 mm was an critical dimension which corresponds to an abrupt change in the solidification rate. It is also found that (Ni2Sc+NiSc)eutectic was dispersed at grain boundary or between dendritic arms due to the loss of Sc element during melting. While d＞0.5mm (corresponding to the thin plate with thickness of 0.75mm, 1.20mm and 2.65 mm), the solidification structure consists of primary phase B2-NiSc and (Ni2Sc+NiSc)eutectic. While d ＜ 0.5mm (corresponding to the thin plate with thickness of 0.35 mm), the solidification structure is composed of fine globular B2-NiSc and relatively small amounts of (Ni2Sc+NiSc)eutectic. Based on the phase volumetric analyzing of the microstructure with an Image-Pro Plus software, the loss of Sc element during melting was about 3.01~3.10 at%. The eutectic NiSc in the lamellar eutectic structure together with the primary phase B2-NiSc form a larger single phase NiSc, while Ni2Sc with the form of particles is distributed on the grain boundaries after (970 ℃, 72 h) homogenization heat treatment.

The Study on the Precipitation and Mechanical Properties of Steel with Copper

2010 ◽  
Vol 654-656 ◽  
pp. 66-69 ◽  
Author(s):  
Chuang Li ◽  
Xue Min Wang ◽  
Xin Lai He ◽  
Cheng Jia Shang ◽  
Yu He
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Volume Fraction ◽  
Optical Microscope ◽  
Second Phase ◽  
Phase Precipitation ◽  
Precipitation Behavior ◽  
Quenching Temperature ◽  
Bearing Steels ◽  
Transition Electron

The properties and precipitation behavior of Cu-bearing steels have been investigated. The optical microscope and transition electron microscope were employed to study the influence of interrupted cooling and quenching temperature on the precipitation behavior. Also, the properties of samples with different quench processes were tested. The results show that when the steel is interruptedly cooled and quenched from 650-700°C, with the quenching temperature increasing the volume fraction of martensite becomes larger and the hardness becomes higher. When the microstructure is ferrite the second-phase precipitates occurs and they are proved copper-rich particles. However there are no obvious precipitates in martensite. The copper-rich second phase forms by the way of inter-phase precipitation.

Study on the Microstructure and Properties of Fe-C-Si and Fe-C-Al Cast Irons

2011 ◽  
Vol 264-265 ◽  
pp. 1933-1938 ◽  
Author(s):  
S.K. Shaha ◽  
Mohammad M. Haque ◽  
Ahsan Ali Khan
Keyword(s):  
Cast Iron ◽  
Impact Test ◽  
Alloy System ◽  
Optical Microscope ◽  
Al Alloy ◽  
Test Results ◽  
Cast Irons ◽  
Microstructure And Properties ◽  
Cast Product ◽  
The Impact

Two types of cast irons with Fe-C-Si and Fe-C-Al. alloy systems were investigated in the present study. In order to modify the microstructure and properties of cast iron, Al was added to low silicon pig iron that is in Fe-C-Al (Sorel metal) alloy system. Its effect was then studied with comparing to normal Fe-C-Si alloy system. Both cast irons were produced in sand mould of suitable design to provide all information regarding the structure and properties. The microstructure was analyzed using optical microscope which showed the distribution of graphite flakes in pearlite or ferro-pearlite matrix. The size of the graphite flakes in Fe-C-Al system was smaller and more evenly distributed compared to the Fe-C-Si alloy system. The cast product was also characterized by using XRD. The maximum hardness of the Fe-C-Al alloy was measured as 110.2 HRB compared to 89.32 HRB of the conventional Fe-C-Si alloy system. The impact test results showed that Fe-C-Al cast iron has higher impact property than Fe-C-Si cast iron.

Grain Refinement in Titanium-Erbium Alloys

1974 ◽  
Vol 32 ◽  
pp. 522-523
Author(s):  
B. B. Rath ◽  
J. E. O'Neal ◽  
R. J. Lederich
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Grain Refinement ◽  
Grain Growth ◽  
Volume Fraction ◽  
Pure Titanium ◽  
Systematic Investigation ◽  
Second Phase ◽  
Titanium Matrix ◽  
Average Size

Addition of small amounts of erbium has a profound effect on recrystallization and grain growth in titanium. Erbium, because of its negligible solubility in titanium, precipitates in the titanium matrix as a finely dispersed second phase. The presence of this phase, depending on its average size, distribution, and volume fraction in titanium, strongly inhibits the migration of grain boundaries during recrystallization and grain growth, and thus produces ultimate grains of sub-micrometer dimensions. A systematic investigation has been conducted to study the isothermal grain growth in electrolytically pure titanium and titanium-erbium alloys (Er concentration ranging from 0-0.3 at.%) over the temperature range of 450 to 850°C by electron microscopy.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

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