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.

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.

Effect of Heat Treatment on the Structure and Properties of EW75 Magnesium Alloy Plate

2013 ◽  
Vol 747-748 ◽  
pp. 158-165
Author(s):  
Juan Qu ◽  
Kui Zhang ◽  
Ming Long Ma ◽  
Yong Jun Li ◽  
Xing Gang Li
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Solution Process ◽  
Solution Time ◽  
Solution Temperature ◽  
Second Phase ◽  
Alloy Plate ◽  
T6 Heat Treatment ◽  
The Matrix

In this study, Mg-7Gd-5Y-1Nd-0.5Zr alloy (EW75) was produced by melting method and then press-forged into large size plate. The properties of the Mg-7Gd-5Y-1.2Nd-0.5Zr alloy were optimized through T6 heat treatment. The microstructures of alloy were observed by means of optical microscopy (OM), scanning electron microscopy (SEM). Its mechanical properties under different heat treatment conditions were determined by tensile tests. The results indicated that increasing the solid solution temperature and prolonging the solid solution time can both lead to the dissolution of second phase in the alloy back into the matrix. The solid solution temperature affects the dissolution process more than the solid solution time. Grain growth occurred during the solid solution process. The grain size of the matrix enlarges with the increase of solid solution temperature. The tensile test result showed that the tensile strength of the alloy was significantly improved after T6 heat treatment. Its tensile strength in the same direction was nearly 40% up after T6 heat treatment. The analysis shows that T6 heat treatment can effectively eliminate the larger deformed precipitates and beneficial to the formation of hard precipitates, which leads to an improvement in the alloys tensile strength.

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.

Effect of Solution Treatment on Microstructures and Mechanical Properties of Centrifugal Casting Al-Cu Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 548-552
Author(s):  
Jun Li ◽  
Yan Wei Sui ◽  
Ai Hui Liu ◽  
Xin Zhao ◽  
Zhi Sun
Keyword(s):  
Mechanical Properties ◽  
Centrifugal Casting ◽  
Solution Treatment ◽  
Solution Time ◽  
Solution Temperature ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Alloy Casting ◽  
Cu Alloy ◽  
Microstructures And Mechanical Properties

Al-Cu alloy castings are obtained in the vertical centrifugal field. The effects of solution treatment on the microstructures and mechanical properties of Al-Cu alloy casting were studied by OM, micro hardness tester and room temperature tension and compression test. The results show that, the strength, micro hardness and elongation percentage of Al-Cu alloy casting increase firstly and then decrease as the solution temperature increases, and the mechanical properties reach the maximum values as the solution temperature increases to 530°C. As solution time increasing, the mechanical properties of Al-Cu alloy casting increase firstly and then decrease. When the solution time is up to 6 hours, the mechanical properties reach maximum value.

Effect of Solution Treatment on Microstructure and Mechanical Properties of Hot-Extruded Cu-15Ni-8Sn Alloy

2017 ◽  
Vol 898 ◽  
pp. 1156-1162
Author(s):  
Xun Wang ◽  
Chao Zhao ◽  
Yan Gen Yu ◽  
Zong Qiang Luo ◽  
Wei Wen Zhang
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Time ◽  
Solution Temperature ◽  
Scanning Calorimetry ◽  
Annealing Twins ◽  
Optimum Solution ◽  
Electronic Microscope

The effects of solution treatment on the microstructure evolution of hot-extruded Cu-15Ni-8Sn alloy were investigated by optical microscope (OM), scanning electronic microscope (SEM), differential scanning calorimetry (DSC) and tensile testing, and the effects of solution temperature and time on the mechanical properties of the alloys were analyzed. The results indicated that, the γ-phases precipitated at first and then dissolved with the extension of the solution time during solutionizing at 800 C,the volume fraction of theγ-phase reached its peak at about 1h. However when solutionizing at 860°C, theγ-phase solely dissolved gradually with the extension of the solution time . In addition, a small amount of annealing twins appeared intragranular in the process of solution treatment. The γ-phase dissolution and the grain growth of α (Cu) were the main softening factors of the alloy during the solution treatment. Through overall consideration, the optimum solution treatment was annealing at 840°Cfor 1 h.

Effect of Quenching Treatment on Microstructure and Hardness of Mg-9Li-4Al-1Zn-0.5Y Alloy

2017 ◽  
Vol 748 ◽  
pp. 245-249
Author(s):  
Chao Duan ◽  
Jin Liang Huang
Keyword(s):  
Solution Process ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Second Phase ◽  
Strengthening Effect ◽  
X Ray Diffraction ◽  
Β Phase ◽  
Quenching Process ◽  
Solution Strengthening

This paper studies the effect of different solution temperature and quenching medium on Microstructure and hardness of Mg-9Li-4Al-1Zn-0.5Y alloy by means of optical microscope (OM), X-ray diffraction (XRD) and hardness testing. The results show that in the solution process, the higher of the solution temperature is, more of the second phase dissolved in β phase. In the quenching process, the higher of the cooling rate is, more of the second phase dissolved in the β phase precipitates from the super-saturation β matrix, which can greatly weaken the solution strengthening effect. The hardness of the investigated alloy reaches its highest value with solution treatment at 648K and water-quenched treatment, increased from 58HB to 108HB.

Effect of Solution Heat Treatment on Microstructure and Mechanical Properties of Al-Mg-Si Alloy

2020 ◽  
Vol 1003 ◽  
pp. 26-30
Author(s):  
Kai Xin Chen ◽  
Li Zhen Yan ◽  
Yong An Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Alloy Sheet ◽  
Solution Time ◽  
Solution Temperature ◽  
Aluminum Alloy Sheet ◽  
Elongation At Break ◽  
Average Grain Size ◽  
Electron Back Scattered Diffraction

Effects of different solution treatments on microstructure, texture and mechanical properties of 6A16 aluminum alloy sheet were investigated by electron back-scattered diffraction (EBSD) and tensile test. The results show that among the five solution treatments, with the increase of solution temperature and solution time, the average grain size increases and the yield strength of the alloy sheet gradually increases. The maximum elongation at break of the sheet is at 545 °C, and it increases with the increase of solution time. Therefore, the mechanical properties of the sheet are the best when the solution treatment is 545 °C for 5 min.

Effect of Solution Treatment on Microstructure Evolution and Mechanical Behavior of Cu-20Ni-20Mn Alloy

2016 ◽  
Vol 850 ◽  
pp. 773-777
Author(s):  
Wei Bin Xie ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Xu Jun Mi ◽  
Dong Mei Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Mechanical Behavior ◽  
Grain Growth ◽  
Microstructure Evolution ◽  
Hot Forging ◽  
Solution Treatment ◽  
Hardness Test ◽  
Solution Temperature ◽  
Second Phase ◽  
Solution Treated

The influence of solution treatment on microstructure evolution and mechanical behavior of Cu-20Ni-20Mn alloy was investigated by optical microscopy (OM), X-ray diffraction (XRD) and hardness test. The results revealed that both solution temperature and holding time had effect on the grain growth behavior. The grain growth activation energy was determined by grain size of Cu-20Ni-20Mn alloy for different heat treatment temperatures and periods. With increasing temperature of solution treatment, the second phase is gradually dissolved into the Cu-rich matrix, and the lattice parameter of the matrix solution treated at 1173K for 0.5 h was about 3.668 Å. The hardness of the solution-treated alloy was lower than that of hot forging, and the hardness value decreased with the increase of solution temperature, which may be attributed to grain size. The hardening ability, corresponding to the Hall-Petch relationship, decreased linearly with D-1/2.

scholarly journals The Formation of 14H-LPSO in Mg–9Gd–2Y–2Zn–0.5Zr Alloy during Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5758
Author(s):  
Yunfang Liu ◽  
Yaqin Yang ◽  
Ming Yi ◽  
Jianmin Yu ◽  
Baocheng Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Grain Size ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Phase Changes ◽  
Solution Temperature ◽  
Second Phase ◽  
Lpso Phase

There is a new long-period stacking ordered structure in Mg–RE–Zn magnesium alloys, namely the LPSO phase, which can effectively improve the yield strength, elongation, and corrosion resistance of Mg alloys. According to different types of Mg–RE–Zn alloy systems, two transformation modes are involved in the heat treatment transformation process. The first is the alloy without LPSO phase in the as-cast alloy, and the MgxRE phase changes to 14H-LPSO phase. The second is the alloy containing LPSO phase in the as-cast state, and the 14H-LPSO phase is obtained by the transformations of 6H, 18R, and 24R. The effects of different solution parameters on the second phase of Mg–9Gd–2Y–2Zn–0.5Zr alloy were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The precipitation mechanism of 14H-LPSO phase during solution treatment was further clarified. At a solution time of 13 h, the grain size increased rapidly initially and then decreased slightly with increasing solution temperature. The analysis of the volume fraction of the second phase and lattice constant showed that Gd and Y elements in the alloy precipitated from the matrix and formed 14H-LPSO phase after solution treatment at 490 °C for 13 h. At this time, the hardness of the alloy reached the maximum of 74.6 HV. After solution treatment at 500 °C for 13 h, the solid solution degree of the alloy increases, and the grain size and hardness of the alloy remain basically unchanged.

scholarly journals Investigation on Compressive Formability and Microstructure Evolution of 6082-T6 Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 469
Author(s):  
Zhouli Xu ◽  
Huijuan Ma ◽  
Ning Zhao ◽  
Zhili Hu
Keyword(s):  
Aluminum Alloy ◽  
Treatment Time ◽  
Heating Temperature ◽  
Solution Treatment ◽  
Heating Time ◽  
Strengthening Effect ◽  
Forming Process ◽  
Production Time ◽  
Precipitated Phase ◽  
First Choice

The 6xxx aluminum alloy is the first choice for automotive lightweight forgings due to its excellent performance, high strength and low weight. The production time of current aluminum alloy forging generally exceeds 10 h. To reduce the production time of traditional aluminum alloy forgings, 6082-T6 aluminum alloy is used in the forming process. The effects of different heating temperatures (200 °C, 300 °C, and 400 °C) and deformation degrees (30%, 50%, and 70%) on the deformability and properties of 6082-T6 billets have been investigated. The results show that when the heating temperature is higher than 300 °C, the compressive deformation resistance obviously decreases with increasing strength. With compression at 200 °C and 70% deformation with short heating time, the strength of the sample is close to the T6 (solution treatment and artificial aging) state. A large number of dislocations and subgrains were introduced due to the compression deformation, and their amounts decreased as the heating temperature increased. The size of the precipitated phase β′′ slightly grows under a heating temperature of 200 °C. However, when the heating temperature is higher than 300 °C, the precipitated phase gradually changes from β′′, which is optimal for the strengthening effect, to β′ and β, which offer weaker strengthening. Therefore, under a lower heating temperature of 200 °C for 5 min, a large number of dislocations are introduced with the β′′ precipitated phase, leading to higher strength with less heat treatment time.

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