Improvement of Strength and Ductility by Controlling PFZ with Microalloying Elements in Al-Zn-Mg Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 235-238 ◽  
Author(s):  
Tomo Ogura ◽  
Shoichi Hirosawa ◽  
Tatsuo Sato
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Tensile Test ◽  
Tensile Properties ◽  
Aging Process ◽  
Mg Alloys ◽  
Proof Stress ◽  
Mode Change ◽  
Microalloying Elements ◽  
Strength And Ductility

The effectiveness of microalloying addition and two-step aging on the mechanical properties of the Al-Zn-Mg alloy has been investigated using TEM, tensile test and nanoindentation. By decreasing width of PFZ and size of grain boundary precipitates through the addition of (Ag+Sn) or two-step aging process, tensile properties of Al-Zn-Mg alloys are markedly improved. The elongation was quantitatively related to the three microstructural factors; i.e. the width of PFZ, size of grain boundary precipitates and the level of proof stress, to predict ductility of the alloys with known microstructural factors. The fracture mode change is reasonably in terms of the hardness difference between grain interiors and PFZ region by a noindentation technique.

Control of Nano-Precipitates in Age-Hardenable Aluminum Alloys and Their Mechanical Properties

2005 ◽  
Vol 475-479 ◽  
pp. 337-342 ◽  
Author(s):  
Tatsuo Sato ◽  
Shoichi Hirosawa
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Mg Alloys ◽  
Phase Decomposition ◽  
Nano Scale ◽  
Initial Stage ◽  
Negative Effect ◽  
New Type ◽  
Microalloying Elements ◽  
Strength And Ductility

The nano-scale precipitate microstructures and properties of age-hardenable aluminum alloys such as Al-Cu, Al-Mg-Si and Al-Zn-Mg alloys were investigated using conventional electrical resistivity and hardness measurements, TEM and 3D-AP techniques. To increase mechanical strength and ductility of the alloys nano-scale precipitates were effectively controlled by applying new type heat treatments and microalloying elements. In the initial stage of phase decomposition of the alloys containing microalloying elements several types of nanoclusters were formed and distinctly detected by the 3D-AP technique. These nanoclusters greatly affect the nucleation of the subsequent precipitates and resultantly mechanical properties. In Al-Mg-Si and Al-Zn-Mg alloys complicated two-step aging behaviors were found to be originated in the positive or negative effect of the nanoclusters with different structures.

Mechanical Properties of a Novel High-Strength Aluminum-Lithium Alloy

2011 ◽  
Vol 689 ◽  
pp. 385-389 ◽  
Author(s):  
Zhi Shan Yuan ◽  
Zheng Lu ◽  
You Hua Xie ◽  
Xiu Liang Wu ◽  
Sheng Long Dai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Test ◽  
High Strength ◽  
Heat Treatments ◽  
Fracture Toughness Test ◽  
Aluminum Lithium Alloy ◽  
Toughness Test ◽  
Aluminum Lithium ◽  
Strength And Ductility

As a heat treatable aluminum alloy to be used in T6 and T8 temper, belongs to Al-Cu-Li system, a novel high-strength aluminum-lithium alloy 2A97 was developed. In order to improve the relationships of strength and ductility and fracture toughness, and to urge the applications in the aeronautical and aerospace industries, the effects of normal heat treatments and thermomechanical heat treatments on the mechanical properties and fracture toughness were investigated by Transmission Electron Microscope(TEM), Scanning Electronic Microscope (SEM), tensile test, and fracture toughness test. The results show that for the alloy aged at 135 °C for 24 h after quenching and 4 percent plastic deformation, its microstructures are strengthened by strain hardening and precipitation hardening, consisting of fine T1phase, θ″/θ′ phase and δ′ phase densely and homogeneously distributed in the matrix. It yields optimum relationship of strength and ductility, fracture toughness, its σ0.2, σband δ5are 454 MPa, 536 MPa, and 11.8%, respectively. It yields 43.5 MPa·m1/2of Kqvalues higher than that of 42.5 MPa·m1/2 in T6 temper. The fracture morphologies of impact tensile samples of fracture toughness test and normal tensile test were observed, indicating the dominance of intergranular failure and subintergranular failure with some dimples and trangranular failure.

Comparison of Shear, Compressive and Tensile Characteristics of Cast Irons

1973 ◽  
Vol 15 (1) ◽  
pp. 53-60 ◽  
Author(s):  
R. D. Adams ◽  
M. A. O. Fox
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Design Criteria ◽  
Matrix Structure ◽  
Proof Stress ◽  
Cast Irons ◽  
The Matrix ◽  
The Relationship ◽  
Graphite Inclusions ◽  
Strength And Ductility

Cast irons were produced with variations in the quantity and shape of the free graphite inclusions and in the matrix structure to investigate the relationship between the shear, compressive and tensile mechanical properties. Differences were observed which may have a significant effect on design criteria for cast irons. For example, the ratio of shear to tensile strengths decreased from about 1·25 to 0·577 and the ratio of 0·1 per cent proof stress in compression to that in tension decreased from approximately 2 to 11 as the tensile strength (and ductility) were increased.

Effect of Nanocellulose Loading on Tensile Properties of Nitrile Rubber

2017 ◽  
Vol 264 ◽  
pp. 112-115
Author(s):  
Erfan Suryani Abdul Rashid ◽  
Wageeh Abdulhadi Yehye ◽  
Nurhidayatullaili Muhd Julkapli ◽  
Sharifah Bee O.A. Abdul Hamid
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Tensile Test ◽  
Tensile Properties ◽  
Mechanical Performance ◽  
Butadiene Rubber ◽  
Fracture Surfaces ◽  
Scanning Electron

Nanocellulose (NCC) is incorporated into nitrile butadiene rubber (NBR) latex with the composition 0 to 5 phr using dipping method. Mechanical properties of NBR/NCC composites using tensile test was used to characterize their mechanical performance and the fracture surfaces post tensile test were studied. The tensile strength of NBR/NCC composites increase significantly with the addition of nanocellulose. This could be anticipated due to the presence of Van der Waals interaction between hydrophilic natures of nanocellulose with hydrophobic of NBR consequently limits the tearing propagation. The result was supported with the fracture surfaces morphology viewed under Fourier Emission Scanning Electron Microscopy (FESEM).

scholarly journals Effect of the Zn/Mg Ratio on Microstructures, Mechanical Properties and Corrosion Performances of Al-Zn-Mg Alloys

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3299
Author(s):  
Keda Jiang ◽  
Yanquan Lan ◽  
Qinglin Pan ◽  
Yunlai Deng
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Stress Corrosion ◽  
Intergranular Corrosion ◽  
Optical Microscope ◽  
Mg Alloys ◽  
Sensitivity Index ◽  
Second Phase ◽  
Mechanical Properties And Corrosion

The effect of the Zn/Mg ratio on microstructures, mechanical properties and corrosion performances of Al-Zn-Mg alloys was studied. Microstructures were characterized using the optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). Tensile tests, intergranular corrosion (IGC) and stress corrosion cracking (SCC) tests were conducted to study the properties. Microstructures results indicated that with the decrease of the Zn/Mg ratio, the recrystallization proportion and the fraction of second phase decreased, while the size of η’ (MgZn2) phases in grain interior also significantly decreased. The number density of η’ phases in grain interior increased and grain boundary precipitates developed discontinuous distribution with the decrease of the Zn/Mg ratio. These microstructures contributed to the significant improvement of the strength and corrosion resistance. The tensile strength and yield strength increased by 34.1% and 47.4%, respectively, with the Zn/Mg ratio decreased from 11.4 to 6.1. Calculating results indicated that the enhancement of strength mainly contributed from the solid-solution strengthening, grain-boundary strengthening and precipitation strengthening. The intergranular corrosion degree was greatly relieved and the stress corrosion sensitivity index decreased from 0.031 to 0.007 with the Zn/Mg ratio decreased from 11.4 to 6.1.

scholarly journals Influence of Grain Size and Texture on the Yield Strength of Mg Alloys Processed by Severe Plastic Deformation

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jinbao Lin ◽  
Weijie Ren ◽  
Qudong Wang ◽  
Lifeng Ma ◽  
Yongjun Chen
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Yield Strength ◽  
Severe Plastic Deformation ◽  
Flow Behavior ◽  
Influence Factors ◽  
Mg Alloys ◽  
Processing Conditions ◽  
Strength And Ductility

Severe plastic deformation (SPD) has been widely employed to refine the grain size of Mg alloys, with the main objective to improve the strength and ductility of Mg alloys, since the well-known Hall-Petch equation suggests that a decreased grain size leads to an increased yield strength. However, the yield strength of Mg alloys processed by SPD is often decreased even though the grain size is effectively reduced. The abnormal flow behavior in Mg alloys processed by SPD has attracted great attention although this mechanism is still unclear, due to its complex and extensive influence factors. In this paper, the relationships between the processing conditions, grain refinement, and mechanical properties of the SPD treated Mg alloys are reviewed, with the emphasis on the effects of grain size and texture on the yield strength.

Microstructure and Mechanical Properties of Brazed Joints Used in Electronic Devices

2014 ◽  
Vol 936 ◽  
pp. 1671-1675
Author(s):  
Xue Rui Wu ◽  
Wen Qing Qu ◽  
Hai Tao Li
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Grain Boundary ◽  
Tensile Test ◽  
Filler Metal ◽  
Electronic Devices ◽  
Nickel Content ◽  
Microstructure And Mechanical Properties ◽  
Brazed Joints ◽  
Content Alloy

The microstructure and mechanical properties of brazed joints of oxygen-free copper and oxygen-free copper, nickel-plated kovar, monel, nickel-plated stainless steel were respectively studied by using AgCu28 and AuCu20 filler metal. Effects of different filler metal on microstructure of the brazed joints were analyzed through metallurgical microscope, SEM, EPMA. The brazed joints tensile strengths were analyzed through tensile test. The results indicate that the brazing process of oxygen-free copper and nickel content alloy used AgCu28 filler metal, nickel element is easy to diffused into AgCu28, AgCu28 filler metal with nickel element wetting spreadability along grain boundary of the oxygen - free copper, resulting in the penetration of the grain boundary of the oxygen-free copper. The joints brazed by AuCu20 filler metal have the better performance than the joints brazed by AgCu28 filler metal.

scholarly journals The Precipitation Processes and Mechanical Properties of Aged Inconel 718 Alloy After Annealing

2017 ◽  
Vol 62 (3) ◽  
pp. 1695-1702 ◽  
Author(s):  
P. Maj ◽  
B. Adamczyk-Cieslak ◽  
M. Slesik ◽  
J. Mizera ◽  
T. Pieja ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Aging Process ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
Transmission Microscopy ◽  
Nickel Iron ◽  
Temperature Range ◽  
Hardness Tests ◽  
Strength And Ductility

AbstractInconel 718 is a precipitation hardenable nickel-iron based superalloy. It has exceptionally high strength and ductility compared to other metallic materials. This is due to intense precipitation of the γ’ and γ” strengthening phases in the temperature range 650-850°C. The main purpose of the authors was to analyze the aging process in Inconel 718 obtained in accordance with AMS 5596, and its effect on the mechanical properties. Tensile and hardness tests were used to evaluate the mechanical properties, in the initial aging process and after reheating, as a function of temperature and time respectively in the ranges 650°-900°C and 5-480 min. In addition, to link the mechanical properties with the microstructure transmission microscopy observations were carried out in selected specimens. As a result, factors influencing the microstructure changes at various stages of strengthening were observed. The authors found that the γ’’ phase nucleates mostly homogenously in the temperature range 650-750°C, causing the greatest increase in strength. On the other hand, the γ’ and δ phases are formed heterogeneously at 850°C or after longer annealing in 800°C, which may weaken the material.

scholarly journals Effect of Microalloying Elements on the Heat Treatment Response and Tensile Properties of Al-Si-Mg Alloys

2018 ◽  
Author(s):  
Mohamed F. Ibrahim ◽  
Mohamed H. Abdelaziz ◽  
Herbert W. Doty ◽  
Salvador Valtierra ◽  
Fawzy H. Samuel
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Treatment Response ◽  
Mg Alloys ◽  
Microalloying Elements
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