scholarly journals Comparative Study of Two Aging Treatments on Microstructure and Mechanical Properties of an Ultra-Fine Grained Mg-10Y-6Gd-1.5Zn-0.5Zr Alloy

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 658 ◽  
Author(s):  
Huan Liu ◽  
He Huang ◽  
Ce Wang ◽  
Jia Ju ◽  
Jiapeng Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Aging Treatment ◽  
High Strength ◽  
Tensile Tests ◽  
Aged Alloy ◽  
Fine Grained ◽  
Peak Aging ◽  
Peak Aged ◽  
Strength And Ductility

Developing high strength and high ductility magnesium alloys is an important issue for weight-reduction applications. In this work, we explored the feasibility of manipulating nanosized precipitates on LPSO-contained (long period stacking ordered phase) ultra-fine grained (UFG) magnesium alloy to obtain simultaneously improved strength and ductility. The effect of two aging treatments on microstructures and mechanical properties of an UFG Mg-10Y-6Gd-1.5Zn-0.5Zr alloy was systematically investigated and compared by a series of microstructure characterization techniques and tensile test. The results showed that nano γ’’ precipitates were successfully introduced in T5 peak aged alloy with no obvious increase in grain size. While T6 peak aging treatment stimulated the growth of α-Mg grains to 4.3 μm (fine grained, FG), together with the precipitation of γ’’ precipitates. Tensile tests revealed that both aging treatments remarkably improved the strengths but impaired the ductility slightly. The T5 peak aged alloy exhibited the optimum mechanical properties with ultimate strength of 431 MPa and elongation of 13.5%. This work provided a novel strategy to simultaneously improve the strength and ductility of magnesium alloys by integrating the intense precipitation strengthening with ductile LPSO-contained UFG/FG microstructure.

Effect of Artificial Aging on Microstructures and Mechanical Properties of Extruded Mg Alloy ZK60

2014 ◽  
Vol 697 ◽  
pp. 72-75
Author(s):  
De Liang Yin ◽  
Jian Qiao ◽  
Hong Liang Cui
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Aging Time ◽  
Artificial Aging ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Tensile Yield Strength ◽  
Uniaxial Tensile ◽  
Fracture Elongation ◽  
Strength And Ductility

An extruded ZK60 magnesium alloy was subjected to artificial aging at 180 oC for an investigation of the effect of aging time on its precipitation behavior and mechanical properties. Uniaxial tensile tests were conducted to obtain the mechanical properties. Optical microscopy and transmission electron microscopy (TEM) were employed to observe microstructure change before and after aging treatment. It is shown that, both tensile yield strength and ultimate tensile strength increases with aging time. The fracture elongation after aging for 20 h reaches up to 21.0%, and the yield strength increases to 269.5 MPa, 19.4% higher than that of extruded specimens (un-aged), showing a good match of strength and ductility. Three newly-formed precipitates were observed after aging for over 20 h, among which particulate and dispersive precipitates should be responsible for the good combination of strength and ductility.

Microstructure and Mechanical Properties of Aged Mg-12Gd-2Y-0.5Zr Alloy Addition with Sb

2011 ◽  
Vol 261-263 ◽  
pp. 693-696
Author(s):  
Ke Jie Li ◽  
Quan An Li
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Precipitation Strengthening ◽  
Aged Alloy ◽  
Long Period ◽  
Casting Technology ◽  
Alloy Addition ◽  
Solution Strengthening

The Mg-12Gd-2Y-0.5Sm-0.5Sb-0.5Zr (wt.%) alloy was prepared by casting technology. The microstructure was investigated after solution and aging treatment (i.e. T6 heat treatment). Tensile tests were performed at a crosshead speed of 1 mm/min at ambient and elevated temperature atmosphere. The results show that the aged alloy was mainly composed of α-Mg matrix, Mg5Gd phase and dispersed long-period ordered β' precipitates. At 523K, the alloy has shown the superior tensile strength (i.e. 345.5 MPa). The strength mechanism was solution strengthening of RE and precipitation strengthening of dispersive LPO structure β' and stable Mg5Gd precipitatesin Mg matrix.

An Analysis of the Microstructure and Mechanical Properties of Rapidly Solidified Al-1Fe-1Ni-5Mg Alloy

2015 ◽  
Vol 641 ◽  
pp. 3-9
Author(s):  
Anna Kula ◽  
Ludwik Blaz ◽  
Makoto Sugamata
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Spray Deposition ◽  
Hot Extrusion ◽  
High Strength ◽  
Fine Grained ◽  
Rate Dependent ◽  
Fine Grained Material ◽  
Rapidly Solidified ◽  
Strength And Ductility

Experiments on Al-1Fe-1Ni-5Mg alloy were performed to determine the effect of rapid solidification (RS) on the material strengthening, which result from the refining of the grain size and intermetallic compounds. Additionally, an enhancement of the material strengthening due to magnesium addition was also observed. RS procedure was performed using spray deposition of the molten alloy on the rotating water-cooled copper roll. As a result, highly refined structure of rapidly solidified flakes was obtained. Using common powder metallurgy (PM) techniques, i.e. cold pressing, vacuum degassing and hot extrusion, as received RS-flakes were consolidated to the bulk PM materials. For comparison purposes, the conventionally cast and hot extruded Al-1Fe-1Ni-5Mg alloy was studied as well. RS process combined with hot pressing and extrusion procedure was found to be very effective method for the manufacture of fine grained material and effective refinement of intermetallic compounds. However some inhomogenity of particles distribution was observed, which was ascribed to varied cooling rate dependent on the particular spray-drop size. Mechanical properties of as-extruded material were examined using compression test at 293K – 873K. High strength and ductility of as-extruded RS material with respect to conventionally produced alloy were observed. However, the effect of enhanced mechanical properties of RS material is observed only at low deformation temperatures. It was found that increasing deformation temperature above 400K results in negligible hardening of RS samples if compared to conventionally produced material.

Precipitation Hardening Formation in Mg6Zn0.5Y Alloy as an Engine Block Application

2017 ◽  
Vol 739 ◽  
pp. 220-224
Author(s):  
Agung Purniawan ◽  
Sutarsis ◽  
Sigit Tri Wicaksono
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Precipitation Hardening ◽  
Variable Temperature ◽  
Aging Treatment ◽  
High Strength ◽  
Aircraft Engines ◽  
Rare Element ◽  
Hardening Treatment ◽  
Hardness Values

Magnesium alloys have been widely applied in the automotive world cars or motorcycles and aircraft engines. This is because the weight of the magnesium itself is very lightweight and have high strength. And magnesium alloys have good thermal conductivity, high elastic modulus and good mechanical properties. Magnesium in engineering applications is usually in the mix with elements such as Al, Ag, Mn, Zn, Si, Zr and RE (rare element). Magnesium alloys with zinc are mostly found and used. This research has been carried out precipitation hardening treatment-Mg alloy-0.5Y 6Zn using variable temperature 150oC, 175oC and 200oC with a holding time of 12 hours, 24 hours and 36 hours. The results show microstructure formed is αMg, MgZn, and Mg3Zn6Y (i-Phase). The formation of precipitates during the process of aging raise hardness values up to 75.8 BHN. Aging treatment reduces the thermal resistance of the alloy Mg-6Zn-0.5%Y.

Corrosion of New Wrought Magnesium Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 839-844 ◽  
Author(s):  
Young Gee Na ◽  
Dan Eliezer ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Corrosion Behavior ◽  
Weight Ratio ◽  
Hot Extrusion ◽  
High Strength ◽  
Tensile Tests ◽  
Mechanical Properties And Corrosion ◽  
Extrusion Method

The development of new components with magnesium alloys for the automotive industry has increased in recent years due to their high potential as structural materials for low density and high strength/weight ratio demands. However, the limited mechanical properties of the magnesium alloys have led to search new kind of magnesium alloys for better strength and ductility. The main objective of this research is to investigate the mechanical properties and the corrosion behavior of new wrought magnesium alloys; Mg-Zn-Ag (ZQ) and Mg-Zn-Si (ZS) alloys. The ZQ6X and ZS6X samples were fabricated using hot extrusion method. Tensile tests and immersion tests were carried out on the specimens from the extruded rods, which contained different amounts of silver or silicon, in order to evaluate the mechanical properties and corrosion behavior. The microstructure was examined using optical and electron microscopy (TEM and SEM) and EDS. The results showed that the addition of silver improved the mechanical properties but decreased the corrosion resistance. The addition of silicon improved both mechanical properties and corrosion resistance. These results can be explained by the effects of alloying elements on the microstructures of the Mg-Zn alloys such as grain size and precipitates caused by the change in precipitation and recrystallization behavior.

Microstructure and Mechanical Properties of Mg-12Gd-2Y-2Sm-0.5Zr Alloy

2013 ◽  
Vol 750-752 ◽  
pp. 611-614
Author(s):  
Zhi Chen ◽  
Quan An Li ◽  
Wen Jian Liu ◽  
Xiao Jie Song
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Aged Alloy ◽  
Induction Melting ◽  
Microstructure And Mechanical Properties ◽  
Precipitated Phases

The Mg-12Gd-2Y-2Sm-0.5Zr (wt.%) alloy was prepared by induction melting. After solution and aging treatment, the microstructure and mechanical properties of alloy was investigated by optical microscope, XRD and tensile tests. The results show that the aged alloy is mainly composed by α-Mg matrix, Mg24Y5 and Mg5Gd phase, and these precipitated phases distribute in the grain dispersively. The mechanical properties of alloy were tested at room temperature and 200-300°C.

Effect of Aging on Microstructure and Performance after Superplastic Deformation of Fine Grained 1420 Al-Li Alloy

2014 ◽  
Vol 936 ◽  
pp. 1647-1652
Author(s):  
Yan Ling Zhang ◽  
Hong Liang Hou ◽  
Yao Qi Wang
Keyword(s):  
Mechanical Properties ◽  
Artificial Aging ◽  
Superplastic Forming ◽  
Tensile Tests ◽  
Strengthening Mechanism ◽  
Fine Grained ◽  
And Performance ◽  
Relationship Of ◽  
Microstructure And Performance ◽  
Strength And Ductility

Superplastic forming (SPF) is an important process for forming fine grained 1420 Al-Li alloy. However, the mechanical properties will be decreased after deforming at high temperature. How to obtain the optimize relationship of strength and ductility after SPF is one of the key problems for the process. In this paper, a set of artificial aging tests including single and two-step aging were carried out, which are the typical strengthening process for Al-Li alloy. Based on experimental results, strength and elongation were studied by means of tensile tests at room temperature, and the effect of aging processes on mechanical properties was analyzed. Finally, the microstructures fore and after aging were examined by OM and TEM, and the strengthening mechanism of 1420 Al-Li alloy was further studied. It is found that artificial aging especially two-step aging can increase mechanical properties of post-SPF material obviously, and δ (Al3Li) is the primary strengthening phase.

scholarly journals Excellent mechanical properties of taenite in meteoric iron

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shohei Ueki ◽  
Yoji Mine ◽  
Kazuki Takashima
Keyword(s):  
Mechanical Properties ◽  
Nitrogen Solubility ◽  
High Strength ◽  
Tensile Tests ◽  
Metallographic Analysis ◽  
Advanced High Strength Steel ◽  
Analysis Techniques ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Strength And Ductility

AbstractMeteoric iron is the metal that humans first obtained and used in the earliest stage of metal culture. Advances in metallographic analysis techniques have revealed that meteoric iron largely comprises kamacite, taenite, and cohenite, which correspond to ferrite, austenite, and cementite in artificial steel, respectively. Although the mechanical properties of meteoric irons were measured previously to understand their origin and history, the genuine mechanical properties of meteoric iron remain unknown because of its complex microstructure and the pre-existing cracks in cohenite. Using micro-tensile tests to analyse the single-crystalline constituents of the Canyon Diablo meteorite, herein, we show that the taenite matrix exhibits excellent balance between yield strength and ductility superior to that of the kamacite matrix. We found that taenite is rich in nitrogen despite containing a large amount of nickel, which decreases the nitrogen solubility, suggesting that solid-solution strengthening via nitrogen is highly effective for the Fe–Ni system. Our findings not only provide insights for developing advanced high-strength steel but also help understand the mysterious relationship between nitrogen and nickel contents in steel. Like ancient peoples believed that meteoric iron was a gift from the heavens, the findings herein imply that this thought continues even now.

Die Forging of High-Strength Magnesium Alloys – the Structure and Mechanical Properties in Different Heat Treatment Conditions / Kucie Matrycowe Wysokowytrzymałych Stopów Mg – Struktura I Własciwosci Mechaniczne W Róznych Stanach Obróbki Cieplnej

2013 ◽  
Vol 58 (1) ◽  
pp. 127-132 ◽  
Author(s):  
B. Płonka ◽  
M. Lech-Grega ◽  
K. Remsak ◽  
P. Korczak ◽  
A. Kłyszewski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Magnesium Alloys ◽  
High Strength ◽  
Hydraulic Press ◽  
Forging Process ◽  
Fine Grained ◽  
Die Forging ◽  
Treatment Conditions ◽  
Fine Grained Structure

The object of this study was to develop parameter of the die forging process, such as feedstock temperature and to investigate her impact on the structure and mechanical properties of magnesium alloys in different heat treatment conditions. Tests were carried out on a 2,5MN maximum capacity vertical hydraulic press using forgings of sample (model) shapes. Then, based on the results obtained in previous work, research was carried out to develop for items forged from magnesium alloys the parameters of heat treatment to the T5 and T6 condition in the context of achieving possibly homogeneous and fine-grained structure and, consequently, high mechanical properties.

Microstructure and Mechanical Properties of 6013 Aluminium Alloy Processed by a Combination of ECAP and Preaging Treatment

2016 ◽  
Vol 877 ◽  
pp. 437-443
Author(s):  
Jia Wei Jiang ◽  
Man Ping Liu ◽  
Yang Liu ◽  
Kai Tang ◽  
Zi Bo Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dislocation Density ◽  
Average Length ◽  
High Strength ◽  
Tensile Tests ◽  
Tem Analysis ◽  
Average Dislocation Density ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Peak Aging

Microstructure and mechanical properties of a 6013 Al-Mg-Si-Cu aluminum alloy processed by a combination of equal channel angular pressing (ECAP) and preaging treatment were comparatively investigated using quantitative X-ray diffraction (XRD) measurements, transmission electron microscopy (TEM) and tensile tests. In addition, the precipitation sequences were obtained by thermodynamic calculations using the FactSage software package. Average grain sizes measured by XRD are in the range 211–501 nm while the average dislocation density is in the range 0.35-1.0 × 1014 m-2 in the deformed alloy. TEM analysis reveals that fine needle β′′ precipitates with an average length of 4-10 nm are uniformly dispersed in the preaging ECAPed alloy. The local dislocation density in this sample is as high as 2.2×1017 m-2. The strength is significantly increased in the preaging-ECAPed samples as compared to that of the undeformed counterparts. The highest yield strength among the preaging ECAPed alloys is 322 MPa. This value is about 1.25 times higher than that (258 MPa) of the static peak-aging sample. The high strength in the preaging ECAPed alloy is suggested to be related to grain size strengthening and dislocation strengthening, as well as precipitation strengthening contributed from both preaging treatment and ECAP deformation.

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