scholarly journals Effects of Gd, Y Content on the Microstructure and Mechanical Properties of Mg-Gd-Y-Nd-Zr Alloy

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 790 ◽  
Author(s):  
Changping Tang ◽  
Kai Wu ◽  
Wenhui Liu ◽  
Di Feng ◽  
Xuezhao Wang ◽  
...  

The effects of Gd, Y content on the microstructure and mechanical properties of Mg-Gd-Y-Nd-Zr alloy were investigated using hardness measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and uniaxial tensile testing. The results indicate that the alloys in as-cast condition mainly consist of α-Mg matrix and non-equilibrium eutectic Mg5.05RE (RE = Gd, Y, Nd). After solution treatment, the non-equilibrium eutectics dissolved into the matrix but some block shaped RE-rich particles were left at the grain boundaries and within grains. These particles are especially Y-rich and deteriorate the mechanical properties of the alloys. Both the compositions of the eutectic and the block shaped particle were independent of the total Gd, Y content of the alloys, but the number of the particles increases as the total Gd, Y content increases. The ultimate tensile strength increases as the total Gd, Y content decreases. A Mg-5.56Gd-3.38Y-1.11Nd-0.48Zr alloy with the highest ultimate tensile strength of 280 MPa and an elongation of 1.3% was fabricated. The high strength is attributed to the age hardening behavior and the decrease in block shaped particles.

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%.


2007 ◽  
Vol 546-549 ◽  
pp. 159-162 ◽  
Author(s):  
Yang Zhao ◽  
Qu Dong Wang ◽  
Jin Hai Gu ◽  
Yan Gao ◽  
Yan Tong

Microstructure and mechanical properties of three kinds of Mg-Gd-Sm-Zr alloys have been analyzed in this paper. Results exhibit that the microstructure of as-cast Mg-Gd-Sm-Zr alloy contains α-Mg and eutectic compounds which are mainly comprised of most Mg5Gd-base phases and a few Mg41Sm5-base phases by EDX and XRD analysis. Ultimate tensile strength and yield strength of the alloys can be significantly improved after T6 treatment. Mechanical properties of studied alloys in T6 condition are better than that of WE54-T6 alloy.


2007 ◽  
Vol 546-549 ◽  
pp. 105-108 ◽  
Author(s):  
Qu Dong Wang ◽  
Da Quan Li ◽  
Qiang Li ◽  
Wen Jiang Ding

Microstructure and mechanical properties of Mg-Zn-Er-Zr alloys were characterized in detail. The grain size of as-cast Mg-Zn-Er-Zr alloy was greatly decreased by the Mg-Zn-Er phases formed at grain boundaries. The addition of Er can increase the yield strength (YS) but decrease the ultimate tensile strength (UTS) and elongation of as-cast Mg-Zn-Zr alloy. The thermally stable Mg-Zn-Er phases were just partially dissolved into the matrix during solution treatment. And the addition of Er can prolong the precipitation process of Mg-Zn-Zr alloy. Solution-plus-ageing treatment can increase the strength of both the Mg-Zn-Zr and Mg-Zn-Er-Zr alloys, but the strengthening effect of Mg-Zn-Er-Zr alloy was greatly weakened, for the incompletely solution of Mg-Zn-Er phases. Er can greatly enhance the high temperature elongation of Mg-Zn-Zr alloy, but the increase of high temperature tensile strength was just a little.


Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 381
Author(s):  
Dongsheng Qian ◽  
Yuangeng He ◽  
Feng Wang ◽  
Yun Chen ◽  
Xiaohui Lu

The microstructure and mechanical properties of M50 steel subjected to combining cold rolling (CR) with austempering are investigated. The microstructure is characterized using X-ray diffraction and scanning and transmission electron microscopy. The mechanical properties are measured using the uniaxial tensile and Charpy impact tests. It is observed that an excellent combination of ultimate tensile strength (2536 MPa) and impact toughness (128 J) was achieved by combining austempering with CR; of which the ultimate tensile strength increased by 10% compared with traditional martensite quenching-tempering (Q-T) specimen and the impact absorbed energy exhibited 2.3 times of that in Q-T specimen. The observation of the microstructure indicates that CR obviously refines the thickness of bainite sheaves, which is favorable for the formation of ultrafine equiaxed ferrite during tempering.


2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


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.


2016 ◽  
Vol 850 ◽  
pp. 511-518 ◽  
Author(s):  
Hai Jun Liu ◽  
Lie Jun Li ◽  
Jian Wei Niu ◽  
Ji Xiang Gao ◽  
Chuan Dong Ren

The effects of Mg and Cu additions with different contents on the mechanical properties of Al-Si alloy prepared by indirect squeeze casting have been experimentally investigated. The microstructure and mechanical properties of as-cast and T6-treated Al-Si-Cu-Mg alloys were tested by OM, SEM, DSC and tensile measurement, where the samples were produced by artificial aging at 180°C for 8 h after solution treatment at 540°C for 4 h. It has been found that for the as-cast alloys, with increasing contents of Mg and Cu the tensile strength (UTS) and yield strength (YS) increased, while the percentage elongation (El) decreased. And the optimal mechanical properties of Al-Si-Cu-Mg alloys were obtained under the content ratio of Cu/Mg within 4, where the UTS and El reached 426 MPa and 6.3% after T6 treated, respectively.


2013 ◽  
Vol 770 ◽  
pp. 88-91
Author(s):  
Amporn Wiengmoon ◽  
Pattama Apichai ◽  
John T.H. Pearce ◽  
Torranin Chairuangsri

Effects of T6 artificial aging heat treatment on microstructure, microhardness and ultimate tensile strength of Al-4.93 wt% Si-3.47 wt% Cu alloy were investigated. The T6 age hardening treatment consists of solution treatment at 500±5°C for 8 hours followed by quenching into hot water at 80°C and artificial aging at 150, 170, 200 and 230°C for 1-48 hours followed by quenching into hot water. Microstructure was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). XRD and SEM revealed that the microstructure in the as-cast condition consists of primary dendritic α-Al, acicular-plate and globular forms of eutectic Si and intermetallic phases including globular Al2Cu and a flake-shape Al5FeSi. By T6 aging hardening, some intermetallics were dissolved and spheroidized. The volume fraction of eutectic phases in the as-cast, solution-treated, and solution-treated plus aging at 170°C for 24 hours is 17%, 12% and 10%, respectively. TEM results showed that precipitates in under-aging condition at 170° C for 6 hours are in the form of disc shape with the diameter in the range of 7-20 nm. At peak aging at 170°C for 24 hours, thin-plate precipitates with about 3-10 nm in thickness and 20-100 nm in length were found, lengthening to about 30-200 nm at longer aging time. The microhardness and ultimate tensile strength were increased from 71 HV0.05 and 227 MPa in the as-cast condition up to 140 HV0.05 and 400 MPa after solution treatment plus aging at 170°C for 24 hours, and decreased at prolong aging time.


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.


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%.


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