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 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 electropulsing treatment on solid solution behavior of an aged Mg alloy AZ61 strip

2008 ◽  
Vol 23 (10) ◽  
pp. 2685-2691 ◽  
Author(s):  
Yanbin Jiang ◽  
Guoyi Tang ◽  
Lei Guan ◽  
Shaonan Wang ◽  
Zhuohui Xu ◽  
...  
Keyword(s):  
Solid Solution ◽  
Solution Process ◽  
Solution Treatment ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
Solution Behavior ◽  
Β Phase ◽  
Solid Solution Treatment ◽  
Conventional Heat Treatment ◽  
Electropulsing Treatment

The effect of electropulsing treatment (EPT) on the solution behavior of aged Mg alloy AZ61 strip was investigated using scanning electron microscope (SEM) and x-ray diffraction (XRD). It was found that EPT accelerated tremendously the dissolution of β phase into α matrix in an aged Mg alloy AZ61 strip. The dissolution of β phase took place in less than 4 s at relatively low temperature under EPT, compared with that in conventional heat treatment. A mechanism for rapid solid solution process during EPT was proposed based on the coupling of the thermal and athermal effects. The results in this investigation indicated that EPT played an important role in the nonequilibrium microstructural evolution in the alloy. It is supposed that EPT can provide a highly efficient approach for solid solution treatment of the alloy.

Phase Compositions of a Mg-Dy-Zn Alloy Containing LPSO Structures

2015 ◽  
Vol 815 ◽  
pp. 470-473 ◽  
Author(s):  
Xue Cheng Cai ◽  
Qiu Ming Peng ◽  
Da Qing Fang
Keyword(s):  
Solid Solution ◽  
Electron Microscope ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
X Ray Diffraction ◽  
Cast Sample ◽  
Lpso Phase ◽  
Transmission Electron ◽  
Zn Alloy

The phase compositions of a Mg-2Dy-0.5Zn (at.%) alloy under different solid solution temperature was investigated by differential thermal analysis (DSC), X-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results indicated that the as-cast sample was mainly composed of an 18R long period stacking ordered (LPSO) phase and Mg matrix. The disappearance of 18R-LPSO phase, together with the presence of 14H-LPSO phase, occurred when solid solution treatment (SST) was at 535 °C. When the temperature was higher than 535 °C, the 18R-LPSO phase was detected again companied with a new Mg8ZnDy eutectic phase.

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.

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.

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 Microstructure and Mechanical Hardness of Ti-6Al-7Nb

2020 ◽  
Vol 860 ◽  
pp. 218-222
Author(s):  
Della Maharani ◽  
Anawati Anawati ◽  
I. Nyoman Jujur ◽  
Damisih
Keyword(s):  
Centrifugal Casting ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Alloying Element ◽  
Mechanical Hardness ◽  
Β Phase ◽  
Permanent Implant

The metastable β Ti-6Al-4V alloy has been used clinically as a permanent implant material owing to its suitable mechanical properties and biocompatibility. However, the alloying element V was accused of causing toxicity when released to human body fluid. In this work, Nb was used in the alloy to replace V. This study presents the characterization of microstructure and mechanical hardness of as-cast Ti-6Al-7Nb and after solution treatment. The Ti-6Al-7Nb alloy was fabricated by the centrifugal casting method. Solution treatment was carried out at 970°C for 1 hour, followed by oil quenching, and consecutively an aging treatment was applied at 500°C for 8 hours. The microstructure was studied by an optical microscope. The mechanical hardness was measured by microhardness Vickers. The results show that the mechanical hardness of the Ti-6Al-7Nb decreased from 396.2 to 377.2 HV as a result of the solution treatment. Reduction in the hardness was attributed to the phase transformation of α to the β phase during the solution treatment. The XRD analysis showed a reduction in the intensity of α phases at the (011), (012), and (020) planes in the alloy after the solution treatment. The results indicated that the microstructure and mechanical hardness of Ti-6Al7-Nb alloy were affected by the solution treatment.

scholarly journals Microstructure Evolution and Mechanical Properties of AZ80 Mg Alloy during Annular Channel Angular Extrusion Process and Heat Treatment

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4223 ◽  
Author(s):  
Xi Zhao ◽  
Shuchang Li ◽  
Fafa Yan ◽  
Zhimin Zhang ◽  
Yaojin Wu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Annular Channel ◽  
Mg Alloy ◽  
Strengthening Effect ◽  
Β Phase ◽  
Angular Extrusion

Microstructure evolution and mechanical properties of AZ80 Mg alloy during annular channel angular extrusion (350 °C) and heat treatment with varying parameters were investigated, respectively. The results showed that dynamic recrystallization of Mg grains was developed and the dendritic eutectic β-Mg17Al12 phases formed during the solidification were broken into small β-phase particles after hot extrusion. Moreover, a weak texture with two dominant peaks formed owing to the significant grain refinement and the enhanced activation of pyramidal <c + a> slip at relative high temperature. The tension tests showed that both the yield strength and ultimate tensile strength of the extruded alloy were dramatically improved owing to the joint strengthening effect of fine grain and β-phase particles as compared with the homogenized sample. The solution treatment achieved the good plasticity of the alloy resulting from the dissolution of β-phases and the development of more equiaxed grains, while the direct-aging process led to poor alloy elongation as a result of residual eutectic β-phases. After solution and aging treatment, simultaneous bonding strength and plasticity of the alloy were achieved, as a consequence of dissolution of coarse eutectic β-phases and heterogeneous precipitation of a large quantity of newly formed β-phases with both the morphologies of continuous and discontinuous precipitates.

scholarly journals Microstructure and Material Properties of Ti-15mass%Nb Alloy after Gas Nitriding and Quenching Process

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1156
Author(s):  
Yoshikazu Mantani ◽  
Kentaro Shimada ◽  
Naoki Eguchi
Keyword(s):  
Internal Friction ◽  
Hardness Test ◽  
Phase Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Nitriding ◽  
Β Phase ◽  
Quenching Process ◽  
Hardened Surface ◽  
Martensite Structure

The α′ martensite of Ti-15mass%Nb alloy exhibits high internal friction with high damping properties. However, its structure is smoother than the α + β structure. Therefore, a hardened surface layer is required for abrasion resistance. This study fabricated a martensite structure inside the nitriding layer by quenching, after gas nitriding at 1023 and 1223 K. Vickers hardness test, X-ray diffraction, scanning electron microscopy (SEM), and SEM-energy dispersive X-ray (SEM-EDX) measurements from the surface to the inside were made after the heat treatment process. In addition, the Young’s modulus and internal friction were calculated from the damping analysis. The α-TiN0.3 and β phase region was formed at approximately 80 µm from the surface at 1023 and 1223 K, and it was hardened. The internal friction of the gas nitriding and quenching specimens at 1023 and 1223 K was relatively high, though it did not reach that of the as-quenched specimen owing to the influence of the surface structure. From these results, it is considered that these material property values of the alloy can be controlled using the nitriding and quenching processes.

Microstructure and Shape Memory Behavior of Ti-18Nb-6Zr (at.%) Alloy

2021 ◽  
Vol 1016 ◽  
pp. 1368-1373
Author(s):  
Xiao Yun Song ◽  
Wen Jun Ye ◽  
Song Xiao Hui
Keyword(s):  
Shape Memory ◽  
Tensile Deformation ◽  
Solution Treatment ◽  
Tensile Tests ◽  
Martensite Phase ◽  
Air Cooling ◽  
X Ray Diffraction ◽  
Β Phase ◽  
Transmission Electron ◽  
Cold Rolled

The microstructures and shape memory behaviors of Ti-18Nb-6Zr (at.%) alloy subjected to different heat treatments were investigated through optical microscopy (OM), X-ray diffraction (XRD), Transmission electron microscopy (TEM) and tensile tests. Recrystallization occurs in cold-rolled Ti-18Nb-6Zr alloy after solution treatment at 600~800 °C. The cooling rate after solution treatment at 800°C shows a dramatic effect on the microstructure of the alloy. The microstructures for the water quenching (WQ) and oil quenching (OQ) specimens are composed of single α'' martensite phase, while for the air cooling (AC) specimen, the microstructure consists of predominant β phase and a small amount of fine athermal ω phase. During tensile deformation, two-stage yielding is observed in the alloy subjected to 800°C/0.5h/WQ heat treatment. The stress for martensite variants reorientation and the yield stress for plastic deformation are 310MPa and 455MPa, respectievely, and the maximum shape memory strain of 3.1% is obtained with pre-strain of 6%.

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