Effect of Nd Content and Heat Treatment on Microstructure and Mechanical Properties of Mg-Zn-Nd Alloy

2017 ◽  
Vol 898 ◽  
pp. 124-130 ◽  
Author(s):  
Shu Min Xu ◽  
Xin Ying Teng ◽  
Xing Jing Ge ◽  
Jin Yang Zhang

In this paper, the microstructure and mechanical properties of the as-cast and heat treatment of Mg-Zn-Nd alloy was investigated. The alloy was manufactured by a conventional casting method, and then subjected to a heat treatment. The results showed that the microstructure of as-cast alloy was comprised of α-Mg matrix and Mg12Nd phase. With increase of Nd content, the grain size gradually decreased from 25.38 μm to 9.82 μm. The ultimate tensile strength and elongation at room temperature of the Mg94Zn2Nd4 alloy can be reached to 219.63 MPa and 5.31%. After heat treatment, part of the second phase dissolved into the magnesium matrix and the grain size became a little larger than that of the as-cast. The ultimate tensile strength was declined by about 2.5%, and the elongation was increased to 5.47%.

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Yushi Qi ◽  
Heng Wang ◽  
Lili Chen ◽  
Hongming Zhang ◽  
Gang Chen ◽  
...  

A ZK61-Y magnesium (Mg) alloy wheel hub was prepared via liquid forging—isothermal forging process. The effects of Y-element contents on the microstructure and mechanical properties of liquid forging blanks were investigated. The formation order of the second phase was I-phase (Mg3Zn6Y) → W-phase (Mg3Zn3Y2) → Z-phase (Mg12ZnY) with the increase of the Y-element content. Meanwhile, the I-phase and Z-phase formed in the liquid forging process were beneficial to the grain refinement. The numerical simulation of the isothermal forging process was carried out to analyze the effects of forming temperature on the temperature and stress field in the forming parts using the software Deform-3D. Isothermal forging experiments and post heat treatments were conducted. The influence of isothermal forging temperature, heat treatment temperature and preservation time on the microstructure and mechanical properties of the forming parts were also studied. The dynamic recrystallization (DRX), second-phase hardening, and work hardening account for the improvement of properties after the isothermal forging process. The forming part forged at 380 °C displayed the outstanding properties. The elongation, yield strength, and ultimate tensile strength were 18.5%, 150 MPa and 315 MPa, respectively. The samples displayed an increased elongation and decreased strength after heat treatments. The 520 °C—1 h sample possessed the best mechanical properties, the elongation was 25.5%, the yield stress was 125 MPa and the ultimate tensile strength was 282 MPa. This can be ascribed to the recrystallization and the elimination of working hardening. Meanwhile, the second phase transformation (I-phase → W-phase → Mg2Y + MgZn2), dissolution, and decomposition can be observed, as well.


2020 ◽  
Vol 10 (15) ◽  
pp. 5345
Author(s):  
Sayed Amer ◽  
Olga Yakovtseva ◽  
Irina Loginova ◽  
Svetlana Medvedeva ◽  
Alexey Prosviryakov ◽  
...  

The microstructure, phase composition, and mechanical properties during heat treatment and rolling of the novel Al-5.0Cu-3.2Er-0.9Mn-0.3Zr alloy were evaluated. A new quaternary (Al,Cu,Mn,Er) phase with possible composition Al25Cu4Mn2Er was found in the as-cast alloy. Al20Cu2Mn3 and Al3(Zr,Er) phases were nucleated during homogenization, and θ″(Al2Cu) precipitates were nucleated during aging. The metastable disc shaped θ″(Al2Cu) precipitates with a thickness of 5 nm and diameter of 100–200 nm were nucleated mostly on the Al3(Zr,Er) phase precipitates with a diameter of 35 nm. The hardness Vickers (HV) peak was found after the annealing of a rolled alloy at 150 °C due to strengthening by θ″(A2Cu) precipitates, which have a larger effect in materials hardness than do the softening processes. The novel Al-Cu-Er-Mn-Zr alloy has a yield strength (YS) of 320–332 MPa, an ultimate tensile strength (UTS) of 360–370 MPa, and an El. of 3.2–4.0% in the annealed alloy after rolling condition.


2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength


2016 ◽  
Vol 61 (2) ◽  
pp. 475-480
Author(s):  
K. Bolanowski

Abstract The paper analyzes the influence of different heat treatment processes on the mechanical properties of low-alloy high-strength steel denoted by Polish Standard (PN) as 10MnVNb6. One of the findings is that, after aging, the mechanical properties of rolled steel are high: the yield strength may reach > 600 MPa, and the ultimate tensile strength is > 700 MPa. These properties are largely dependent on the grain size and dispersion of the strengthening phase in the ferrite matrix. Aging applied after hot rolling contributes to a considerable rise in the yield strength and ultimate tensile strength. The process of normalization causes a decrease in the average grain size and coalescence (reduction of dispersion) of the strengthening phase. When 10MnVNb6 steel was aged after normalization, there was not a complete recovery in its strength properties.


2018 ◽  
Vol 37 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Hansong Xue ◽  
Xinyu Li ◽  
Weina Zhang ◽  
Zhihui Xing ◽  
Jinsong Rao ◽  
...  

AbstractThe effects of Bi on the microstructure and mechanical properties of AZ80-2Sn alloy were investigated. The results show that the addition of Bi within the as-cast AZ80-2Sn alloy promotes the formation of Mg3Bi2 phase, which can refine the grains and make the eutectic phases discontinuous. The addition of 0.5 % Bi within the as-extruded AZ80-2Sn alloy, the average grain size decreases to 12 μm and the fine granular Mg17Al12 and Mg3Bi2 phases are dispersed in the α-Mg matrix. With an increase in Bi content, the Mg17Al12 and Mg3Bi2 phases become coarsened and the grain size increases. The as-extruded AZ80-2Sn-0.5 %Bi alloy has the optimal properties, and the ultimate tensile strength, yield strength and elongation are 379.6 MPa, 247.1 MPa and 14.8 %, respectively.


2011 ◽  
Vol 197-198 ◽  
pp. 1125-1128 ◽  
Author(s):  
Jing Jiang Nie ◽  
Liang Meng ◽  
Xiu Rong Zhu ◽  
Yong Dong Xu ◽  
Yue Yi Wu ◽  
...  

The effect of the combined action of hot work and heat treatment on the microstructure and mechanical properties of a Mg-2Gd-Nd-0.4Zn-0.3Zr (wt. %) (E21) alloy was investigated. Results showed that the solution treatment time of the ingot played a great effect on the mechanical properties of the extruded alloy. With solution treating time of the ingot increasing, the tensile strength of the extruded alloy decreased gradually, but the elongation increased greatly. The best combination of strength and ductility was achieved for the extruded alloy after the ingot solution treated at 520°C for 3 h, extrusion at 400°C and aging at 200°C for 16 h, namely ultimate tensile strength = 331MPa and elongation = 7.1%.


2016 ◽  
Vol 850 ◽  
pp. 762-767
Author(s):  
Shun Cheng Wang ◽  
Dong Fu Song ◽  
Jing Xu ◽  
Kai Hong Zheng

In the present investigation the casting-forging integrated technology was adopted to manufacture Al-1.1Mg-0.6Si-0.4Cu alloy automobile brake calipers. The effect of forging pressure on the microstructure and mechanical properties of Al-1.1Mg-0.6Si-0.4Cu alloy calipers were studied. The results showed that the shrinkage porosities and cracks in the Al-1.1Mg-0.6Si-0.4Cu alloy calipers could be removed by the forging process. The ultimate tensile strength and elongation of Al-1.1Mg-0.6Si-0.4Cu alloy calipers increased with the increase of forging pressure. When the forging pressure was 120 MPa, the ultimate tensile strength and elongation of Al-1.1Mg-0.6Si-0.4Cu alloy calipers with T6 heat treatment were 365.3 MPa and 11.5%, which were improved by 22.8% and 38.2%, respectively compared with that of Al-1.1Mg-0.6Si-0.4Cu alloy calipers without forging. The tensile fracture images revealed that the fracture modes of Al-1.1Mg-0.6Si-0.4Cu alloy calipers were more ductile at higher forging pressure.


Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 239 ◽  
Author(s):  
Bing He ◽  
Yaobo Hu ◽  
Tianshuo Zhao ◽  
Qingshan Yao ◽  
Fusheng Pan

This study focused on the effects of ageing for various time at 175 °C before hot rolling on microstructure and mechanical properties of AZ80 magnesium alloys. The amount of γ-Mg17Al12 increased in line with ageing time and during the rolling process could facilitate the fine grains and sub-grains, which resulted in an inhomogeneous or bimodal microstructure, and weakening basal-type texture intensity or occurrence of double-peak texture. However, a larger quantity of γ-Mg17Al12 distributed on the matrix in the alloy aged for 240 min, or the precipitates decorating the grain boundaries in the alloy aged for 75 min, were detrimental to the mechanical properties, and lower ultimate tensile strength with elongation were obtained in the two alloys as a result. When the alloy was aged for 200 min, it showed an optimum mechanical property with its yield strength of 281 MPa, ultimate tensile strength of 363 MPa and a medium elongation of 13.3%, which was mainly attributed to the interaction of the hard second phase particles with dislocation movement and the lowest basal-type texture intensity that favored the basal slip.


2018 ◽  
Vol 780 ◽  
pp. 93-97
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen Abdel-Naeim Hassan

The Simple Cyclic extrusion compression (SCEC) has been developed for producing Al-1%Cu alloys with fine microstructures and superior properties. SCEC method was applied for only two-passess.It was found that the grain structure was significantly reduced from 1500 μm to 100 μm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. In addition, cyclic extrusion deformation increased the surface hardness of the alloy by 50 % after two passes.


2013 ◽  
Vol 312 ◽  
pp. 411-414 ◽  
Author(s):  
C.F. Fang ◽  
L.G. Meng ◽  
Y.F. Wu ◽  
L.H. Wang ◽  
X.G. Zhang

The effect of Gd addition on the microstructures and mechanical properties of Mg-5Sn-Zn-Al alloy was investigated with variations of Gd contents. These results show that adding Gd can effectively refine the grain size and growth. In addition, the solubility of Gd increases the lattice constants ofα-Mg phase. Accordingly, the tensile properties of the as-cast Mg-5Sn-Zn-Al alloy are improved by the addition of Gd. The Mg-5Sn-Zn-Al-0.4Gd exhibits the highest tensile properties, and the values of the yield and ultimate tensile strength and elongation are 111 MPa, 188 MPa and 18.0%, respectively.


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