Effect of Stepped Solution Treatment on Microstructure and Properties of AA7085 Aluminum Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 786-792
Author(s):  
Chun Mei Li ◽  
Zhi Qian Chen ◽  
Su Min Zeng ◽  
Nan Pu Cheng ◽  
Zhen Hua Geng ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Tensile Fracture ◽  
Tensile Fracture Surface ◽  
The Matrix ◽  
Initial Melting ◽  
Statistic Theory ◽  
Lower Temperature ◽  
Multi Phase

The effect of stepped solution treatment on the mechanical properties and the microstructure of AA7085 have been investigated compared to AA7050. Optical and electron microscopy observation and electron probe microanalysis were used to analyze the microstructure and tensile fracture surface of AA7085 and AA7050 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to seek the differences of microstructure characters between AA7085 and AA7050. The results indicate that higher content of Zn along with lower content of Mg and Cu and strictly confined Fe and Si made the matrix of AA7085 get a larger single phase and a higher melting temperature of multi-phase eutectics. By using a lower temperature pretreatment, the initial melting temperature of the alloys can be increased. Consequently complete dissolution of remnant constituents was achieved without overheating. Based on thermodynamics statistic theory, the supersaturation degree of the matrix and the density of cavity may be increased with the elevation of the lattermost solution temperature, which resultes in the increase of fracture toughness and optimization of the microstructure after aging.

Effect of Solution Treatment on Second Phase Dissolution for an Al-9.2Zn-2.0Mg-1.9Cu Alloy

2020 ◽  
Vol 993 ◽  
pp. 321-326
Author(s):  
Hong Wei Liu ◽  
Kai Wen ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
Li Zhen Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Second Phase ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Phase Dissolution ◽  
Solution Treated ◽  
The Matrix

The second phase dissolution of Al-9.2Zn-2.0Mg-1.9Cu alloy conducted by various temperatures of 2h was researched with the help of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrical conductivity and differential scanning calorimetry (DSC) analysis. The results gave rise to the second phase existence of Mg(Zn,Cu,Al)2 and Fe-containing phases in the as-extruded alloy. When the alloy solution treated with a temperature varied from 450°C to 470°C, a small quantity of Mg(Zn,Cu,Al)2 phase still existed in the alloy while its content exhibited a decrement trend with the solution temperature rose. For the alloy solution treated at a temperature of 475°C, Mg(Zn,Cu,Al)2 phase dissolved into the matrix completely while Fe-containing phase still remained. The electrical conductivity of quenched alloy decrease with the solution temperature increase and reached a minimum value at 470°C, and then rose slightly for the solution temperature of 475°C.

scholarly journals Evaluation of the Aging Effect on the Microstructure of Co-28Cr-6Mo-0.3C Alloy: Experimental Characterization and Computational Thermodynamics

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 581 ◽  
Author(s):  
Shahab Zangeneh ◽  
Ersoy Erisir ◽  
Mahmoud Abbasi ◽  
Ali Ramazani
Keyword(s):  
Martensitic Transformation ◽  
Solution Treatment ◽  
Aging Effect ◽  
Sample Solution ◽  
Solution Temperature ◽  
Solution Treated ◽  
The Matrix ◽  
Fcc Phase ◽  
Experimental Findings ◽  
Lamellar Type

In the current research, we studied the role of the solution treatment and aging on the microstructure of a Co–28Cr–5Mo–0.3C alloy. We used metallographic observations, scanning electron microscopy (SEM), and hardness measurements for the evaluations. We also made a comparison between the phase equilibrium calculated with Thermo-Calc, using TCFE8 and TCNI8 thermodynamic databases and experimental findings. The experimental results showed that the transformation of the metastable FCC phase to the HCP phase during aging was extremely sensitive to the solution treatment prior to aging. The effect of the increase in the solution temperature and time was detectable through promotion of the martensitic transformation during quenching in which HCP1 (straight bands) and HCP2 (lamellar-type constitution) phases had developed. In contrast, a low solution temperature and time caused most of the primary carbides to remain in an undissolved condition in the matrix; therefore, during aging, no sign of the FCC to HCP1 (straight bands) phase transformation could be observed. However, we observed the formation of the HCP2 phase (lamellar-type constitution) at the grain boundaries. In addition, the X-ray diffraction pattern indicated that the sample solution treated at lower temperatures and shorter times had a stronger martensitic transformation during aging compared to the sample solution treated at higher temperatures and longer times. Hardness measurements confirmed the results. Thermodynamical calculations showed that an agreement existed between the experiments and calculations. We also discuss the results from the TCFE8 and TCNI8 databases.

Effect of Solution Temperature on the Microstructure and Mechanical Properties of Wrought 316LN Stainless Steel

2014 ◽  
Vol 915-916 ◽  
pp. 576-582 ◽  
Author(s):  
H. C. Wu ◽  
B. Yang ◽  
Ming Xian Zhang ◽  
Sheng Long Wang ◽  
Y. Z. Shi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Tensile Fracture ◽  
316Ln Stainless Steel ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Fracture Morphologies

The effect of forging and solution temperature on the microstructure and mechanical properties of 316LN stainless steel has been investigated by optical microscope, tensile testing machine and scanning electron microscope (SEM). The results show that the average grain size of the steel was refined from 150μm to 70μm after forging and solution treatment. With increasing solution temperature, the tensile strength and yield strength decreased. On the contrary, the elongation of the steel increased with increasing solution temperature except at 1200°C. The tensile strength of the samples forged at 1100°C is better than those of the samples forged at 1000 and 1200°Cafter solution treatment. Tensile fracture morphologies observation showed that all the specimens have ductile fracture morphologies. With increasing solution temperature, the toughness of the steel becomes better and better except at 1200°C. Both the microstructure and mechanical properties of the 316LN stainless steel have been improved after forging at 1100°C and following by solution treatment at 1150°C.

scholarly journals Effect of Heat Treatment on the Microstructure and Mechanical Properties of a Composite Made of Al-Si-Cu-Mg Aluminum Alloy Reinforced with SiC Particles

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1205
Author(s):  
Li ◽  
Yan ◽  
Wang ◽  
Li ◽  
Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Optimal Solution ◽  
Tensile Fracture ◽  
Large Area ◽  
Tensile Fracture Surface ◽  
Sic Particles ◽  
Eutectic Si

In this paper, the effect of heat treatment (solution treatment and artificial aging) on the microstructure and properties of as-cast Al5Si1Cu0.5Mg aluminum alloy and its composite reinforced with 1.5 wt.% SiC particles was studied. The results showed that at 520 °C the optimal solution time for the aluminum alloy and its composite is 9 h and 6 h, respectively. After solution treatment, the microstructure of these two materials consists of a uniform distribution of nearly spherical eutectic Si and skeletal γ phase, furthermore, the composite eutectic Si phase is smaller and γ phase is more dispersed. After artificial aging at 175 °C for 6 h, the microstructure of the composite is more dispersed and finer than that of the aluminum alloy on the whole and Al2Cu is precipitated. After heat treatment, the microhardness, ultimate tensile strength, and elongation of the aluminum alloy and its composite are higher than those of the as-casts. At the same time, the morphology of tensile fracture surface changes very much from a large area of cleavage plane to a large number of dimples and the tearing ridges become thicker for both the aluminum alloy and its composite.

Precipitation Within a Precipitate—Nickel-Rich Alloys of Nickel, Aluminum and Titanium

1971 ◽  
Vol 29 ◽  
pp. 202-203
Author(s):  
J. M. Oblak ◽  
B. H. Kear ◽  
G. R. Leverant
Keyword(s):  
Phase Boundary ◽  
Cooling Rate ◽  
Single Phase ◽  
Solution Temperature ◽  
Ti Alloy ◽  
Nickel Aluminum ◽  
Solvus Temperature ◽  
The Matrix ◽  
Lower Temperature

Figure 1 shows how a precipitate of γ might form within a precipitate of γ' in a given Ni-Al-Ti alloy. The alloy reverts to single phase fcc γ on heating above the solvus temperature TS. Upon aging at T1 an LI2 γ' Ni3 (Al,Ti) phase of composition is formed and is in equilibrium with a γ matrix of composition. . If the alloy is subsequently aged at a lower temperature T2, not only does additional γ' form within the matrix, but γ can also precipitate within γ', provided that the γ' phase boundary is as represented.In this study a Ni-10.7Al-5.1Ti (at. %) alloy was air cooled from a solution temperature of 2250°F to form coarse γ' particles. The cooling rate was sufficiently rapid that equilibrium was not. achieved at temperatures corresponding to T2 in Figure 1. Samples were then aged for 16 hours at l400°F and their microstructure examined. As evident in Figure 2(a,b), the large γ' particles contained small plate-like precipitates after aging and these appeared to lie on {100} planes.

scholarly journals RECYCLING WASTE NATURAL RUBBER LATEX BY BLENDING WITH POLYSTYRENE – CHARACTERIZATION OF MECHANICAL PROPERTIES

2012 ◽  
Vol 06 ◽  
pp. 391-396 ◽  
Author(s):  
O. BOONDAMNOEN ◽  
M. OHSHIMA ◽  
A. R. AZURA ◽  
S. CHUAYJULJIT ◽  
A. ARIFFIN
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Crosslinking Density ◽  
Tensile Fracture ◽  
Rubber Latex ◽  
Tensile Fracture Surface ◽  
The Matrix ◽  
Lower Elongation ◽  
Internal Mixer

Waste natural rubber latex was blended with polystyrene (WNRL/PS) for recycling. A mixture with a 50/50 ratio of rubber to PS was blended by an internal mixer (Haake) at 140 °C and 60 rpm. The PS became the matrix, and the WNRL was dispersed within the matrix. Dynamically vulcanized natural rubber/PS (NRv/PS) blends and natural rubber/PS (NR/PS) blends without vulcanization were also prepared in the same way for comparison. The tensile properties and morphologies of all blends were investigated. The crosslinking density was determined by using the Flory-Rehner equation. The experiments showed that the WNRL/PS blend exhibited a higher tensile strength, Young's modulus and crosslinking density, but a lower elongation at break, than the NRv/PS and NR/PS blends. SEM observations of the tensile fracture surface and TEM observations of the blend morphology indicated that the WNRL/PS blend needed a higher energy to break than the NRv/PS and NR/PS blends.

Main Alloying Influence on Second Phase Dissolution during Solution Treatment of Al-Zn-Mg-Cu Alloys

2021 ◽  
Vol 1035 ◽  
pp. 3-9
Author(s):  
Hong Wei Liu ◽  
Kai Wen ◽  
Wei Cai Ren ◽  
Xi Wu Li ◽  
Yong An Zhang ◽  
...  
Keyword(s):  
Solution Treatment ◽  
Solution Temperature ◽  
Second Phase ◽  
Dsc Analysis ◽  
Phase Dissolution ◽  
Cu Alloys ◽  
Residual Phase ◽  
Solution Treated ◽  
The Matrix ◽  
Second Phases

Second phase dissolution of Al-Zn-Mg-Cu alloys during solution treatment was closely associated with the content of main alloying elements. In present work, the phase characteristics of several Al-Zn-Mg-Cu alloys with various main alloying contents were investigated, and the second phase dissolution of these alloys during solution treatment was analyzed. The results showed that the extrusion alloys possessed abundant second phases, mainly including Mg(Zn,Cu,Al)2 phase and Fe-rich particles. The DSC analysis proved that the larger endothermic peak corresponded to the alloy with larger main alloying content, and the XRD spectrogram also backed up the advantage of Mg(Zn,Cu,Al)2 phase. After solution treated at 450°C, the residual phases remained in the alloys and the quantity of them were positively correlated with the main alloying content. With the increase of solution temperature, the electrical conductivity of the alloys showed a decremental trend, while the alloys with relatively low main alloying contents exhibited an inversion at the solution temperature of 475°C. The SEM observation demonstrated that no Mg(Zn,Cu,Al)2 phase was observed in the alloys with relatively low main alloying contents while seldom still remained in the alloy with high main alloying content after solution treated at 470°C. After solution treated at 475°C, Mg(Zn,Cu,Al)2 phase completely dissolved into the matrix for the alloy with high main alloying content. The statistics of residual phase quantity also proved this.

scholarly journals Study on Ultra-High Temperature Contact Solution Treatment of Al–Zn–Mg–Cu Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 842
Author(s):  
Wenming Jin ◽  
Jianhao Yu ◽  
Zhiqiang Zhang ◽  
Hongjie Jia ◽  
Mingwen Ren
Keyword(s):  
Heating Temperature ◽  
Solution Treatment ◽  
Strengthening Mechanism ◽  
Heating Time ◽  
Solution Time ◽  
Solution Temperature ◽  
Second Phase ◽  
Total Strength ◽  
Cu Alloys ◽  
Short Heating Time

Contact solution treatment (CST) of Al–Zn–Mg–Cu alloys can shorten solution time to within 40 s in comparison with 1800 s with traditional solution treatment using a heating furnace. Heating temperature is the key factor in solution treatment. Considering the short heating time of CST, the ultra-high solution temperature over 500 °C of Al–Zn–Mg–Cu alloys was studied in this work. The effects of solution temperatures on the microstructures and the mechanical properties were investigated. The evolution of the second phases was explored and the strengthening mechanisms were also quantitatively evaluated. The results showed that solution time could be reduced to 10 s with the solution temperature of 535 °C due to the increasing dissolution rate of the second phase and the tensile strength of the aged specimen could reach 545 MPa. Precipitation strengthening was the main strengthening mechanism, accounting for 75.4% of the total strength. Over-burning of grain boundaries occurred when the solution temperature increased to 555 °C, leading to the deterioration of the strength.

scholarly journals Comparison in Deformation Behavior, Microstructure, and Failure Mechanism of Nickel Base Alloy 625 under Two Strain Rates

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2652
Author(s):  
Meng Liu ◽  
Quanyi Wang ◽  
Yifan Cai ◽  
Dong Lu ◽  
Tianjian Wang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Base Alloy ◽  
Inconel 625 ◽  
Tensile Fracture ◽  
Nickel Base Superalloy ◽  
Strain Rates ◽  
Tensile Fracture Surface ◽  
Nickel Base

Tensile deformation behavior and microstructure of nickel-base superalloy Inconel 625 are investigated under different strain rates of 5 × 10−4 s−1 and 5 × 10−5 s−1. According to the experimental results, yield strength and ultimate tensile strength of the alloy increase with the increase in strain rate in room temperature. Microstructure results indicate that the size of dimples is smaller in the tensile fracture surface at low strain rate than the high strain rate, and the number of dimples is also related to the strain rates and twins appear earlier in the specimens with higher strain rates. Apart from Hollomon and Ludwik functions, a new formula considering the variation trend of strength in different deformation stages is deduced and introduced, which fit closer to the tensile curves of the 625 alloy used in the present work at both strain rates. Furthermore, the Schmid factors of tensile samples under two strain rates are calculated and discussed. In the end, typical work hardening behavior resulting from the dislocations slip behavior under different strain rates is observed, and a shearing phenomenon of slip lines cross through the δ precipitates due to the movement of dislocations is also be note.

Effect of Solution Treatment on Microstructures and Hardness of Mg-Gd-Y-Zr Alloy

2014 ◽  
Vol 937 ◽  
pp. 182-186
Author(s):  
Quan An Li ◽  
Lei Lei Chen ◽  
Wen Chuang Liu ◽  
Xing Yuan Zhang ◽  
Hui Zhen Jiang
Keyword(s):  
Vickers Hardness ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Hardness Measurement ◽  
Solution Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Treated ◽  
Primary Particles ◽  
Zr Alloy

The influence of the solution treatment (at the temperature of 500-520°C for 4-12 h) on microstructures and mechanical properties of Mg-Gd-Y-Zr alloy was investigated by means of optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Vickers hardness measurement. The as-cast alloy contains a microstructure consisting of α-Mg matrix, Mg5Gd phase and Mg24Y5phase. With increasing solution temperature and time, the quantity of the primary particles (Mg5Gd and Mg24Y5) in the alloy continually decreased, and the degree of recrystallization gradually increased, which result in the gradual decrease of the Vickers hardness of the solution-treated alloys.

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