Post-Anneal Mechanical Properties of Pre-Strained AA5182-O Sheets

2011 ◽  
Author(s):  
Jingjing Li ◽  
S. Jack Hu ◽  
John E. Carsley ◽  
Theresa M. Lee ◽  
Louis G. Hector ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Equivalent Strain ◽  
Image Correlation ◽  
Forming Limit ◽  
Electron Backscattered Diffraction ◽  
Sheet Rolling ◽  
Post Annealing

The effects of different pre-strain levels, paths and subsequent annealing on the post-annealing mechanical properties of AA5182-O were investigated. Aluminum sheet specimens were pre-strained in uniaxial, plane strain and equibiaxial tension to several equivalent strain levels, annealed at 350°C for short (10 seconds) and long (20 minutes) durations, and then tested for post-annealing mechanical properties, including tensile properties, anisotropy and forming limits. The tensile properties, R-values at 0°, 45° and 90° relative to the sheet rolling direction, and forming limit diagrams (FLDs) exhibited dependencies of pre-strain and annealing history. The importance of the process variables and their effects were identified via designed experiments and analysis of variance. Three-dimensional digital image correlation, which captured the onset of local necking, was employed in the FLD development. Texture in the as-received and deformed sheets was investigated with electron backscattered diffraction and provided a means for linking prestrain and static recovery or recrystallization with microstructure. This guided the understanding of the mechanical property changes observed after preforming and annealing. Ultimately, the expanded forming limit curve demonstrated the advantage of annealing in extending the formability of strained AA5182-O.

Postanneal Mechanical Properties of Prestrained AA5182-O Sheets

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Jingjing Li ◽  
S. Jack Hu ◽  
John E. Carsley ◽  
Theresa M. Lee ◽  
Louis G. Hector ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Electron Backscatter Diffraction ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Equivalent Strain ◽  
Image Correlation ◽  
Forming Limit ◽  
Sheet Rolling ◽  
Static Recovery

The effects of different prestrain levels, paths, and subsequent annealing on the postannealing mechanical properties of AA5182-O were investigated. Aluminum sheet specimens were prestrained in uniaxial, plane strain, and equibiaxial tension to several equivalent strain levels, annealed at 350 °C for short (10 s) and long (20 min) durations and then tested for postannealing mechanical properties, including tensile properties, anisotropy, and forming limits. The tensile properties, R-values at 0, 45, and 90 deg relative to the sheet rolling direction, and forming limit diagrams (FLDs) exhibited dependencies on prestrain and annealing history. The importance of the process variables and their effects were identified via designed experiments and analysis of variance. Three-dimensional digital image correlation, which captured the onset of local necking, was employed in the FLD development. Texture in the as-received and deformed sheets was investigated with electron backscatter diffraction and provided a means for linking prestrain and static recovery or recrystallization with microstructure. This guided the understanding of the mechanical property changes observed after preforming and annealing. Ultimately, the expanded forming limit curve demonstrated the advantage of annealing in extending the formability of strained AA5182-O.

scholarly journals Coupled Thermomechanical Response Measurement of Deformation of Nickel-Based Superalloys Using Full-Field Digital Image Correlation and Infrared Thermography

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2163
Author(s):  
Krzysztof Żaba ◽  
Tomasz Trzepieciński ◽  
Sandra Puchlerska ◽  
Piotr Noga ◽  
Maciej Balcerzak
Keyword(s):  
Surface Temperature ◽  
Strain Rate ◽  
Rolling Direction ◽  
Image Correlation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Response Measurement ◽  
Sheet Rolling ◽  
Inconel Alloys ◽  
The Relationship

The paper is devoted to highlighting the potential application of the quantitative imaging technique through results associated with work hardening, strain rate and heat generated during elastic and plastic deformation. The aim of the research presented in this article is to determine the relationship between deformation in the uniaxial tensile test of samples made of 1-mm-thick nickel-based superalloys and their change in temperature during deformation. The relationship between yield stress and the Taylor–Quinney coefficient and their change with the strain rate were determined. The research material was 1-mm-thick sheets of three grades of Inconel alloys: 625 HX and 718. The Aramis (GOM GmbH, a company of the ZEISS Group) measurement system and high-sensitivity infrared thermal imaging camera were used for the tests. The uniaxial tensile tests were carried out at three different strain rates. A clear tendency to increase the sample temperature with an increase in the strain rate was observed. This conclusion applies to all materials and directions of sample cutting investigated with respect to the sheet-rolling direction. An almost linear correlation was found between the percent strain and the value of the maximum surface temperature of the specimens. The method used is helpful in assessing the extent of homogeneity of the strain and the material effort during its deformation based on the measurement of the surface temperature.

scholarly journals Through-Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam-Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Sheida Sarafan ◽  
Priti Wanjara ◽  
Jean-Benoît Lévesque ◽  
Javad Gholipour ◽  
Henri Champliaud ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Electron Beam ◽  
Residual Stresses ◽  
Tensile Properties ◽  
Martensitic Stainless Steel ◽  
Postweld Heat Treatment ◽  
Image Correlation ◽  
Postweld Heat

In this study, the integrity of electron beam- (EB-) welded CA6NM—a grade of 13% Cr-4% Ni martensitic stainless steel—was assessed through the entire joint thickness of 90 mm after postweld heat treatment (PWHT). The joints were characterized by examining the microstructure, residual stresses, global mechanical properties (static tensile, Charpy impact, and bend), and local properties (yield strength and strain at fracture) in the metallurgically modified regions of the EB welds. The applied PWHT tempered the “fresh” martensite present in the microstructure after welding, which reduced sufficiently the hardness (<280 HV) and residual stresses (<100 MPa) to meet the requirements for hydroelectric turbine assemblies. Also, the properties of the EB joints after PWHT passed the minimum acceptance criteria specified in ASME sections VIII and IX. Specifically, measurement of the global tensile properties indicated that the tensile strengths of the EB welds in the transverse and longitudinal directions were on the same order as that of the base metal (BM). Evaluation of the local tensile properties using a digital image correlation (DIC) methodology showed higher local yield strengths in the fusion zone (FZ) and heat-affected zone (HAZ) of 727 MPa and 740 MPa, respectively, relative to the BM value of 663 MPa. Also, the average impact energies for the FZ and HAZ were 63 J and 148 J, respectively, and attributed to the different failure mechanisms in the HAZ (dimples) versus the FZ (quasi-cleavage consisting of facets and dimples). This study shows that the application of PWHT plays an important role in improving the weld quality and performance of EB-welded CA6NM and provides the essential data for validating the design and manufacturing process for next-generation hydroelectric turbine products.

Three-dimensional digital image correlation measurement of mechanical properties of soft materials

Meccanica ◽  
2014 ◽  
Vol 50 (2) ◽  
pp. 419-428 ◽  
Author(s):  
Wei-Chung Wang ◽  
Yu-An Chiang ◽  
Ken-Jen Yu ◽  
Yi-Chieh Ho ◽  
Hung-Tsan Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Three Dimensional ◽  
Soft Materials ◽  
Correlation Measurement ◽  
Image Correlation

scholarly journals The Structure and Mechanical Properties of Ni-Mo PM Steels with Addition of Mn And Cu

2017 ◽  
Vol 17 (1) ◽  
pp. 37-46
Author(s):  
E. Lichańska ◽  
P. Kulecki ◽  
K. Pańcikiewicz
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Tensile Properties ◽  
Nickel Powder ◽  
Three Dimensional ◽  
Mechanical Tests ◽  
Low Carbon ◽  
Alloyed Powder ◽  
Filamentary Structure ◽  
Eds Analysis

Abstract The aim of the study was to evaluate the effect of chemical composition on the structure and mechanical properties of Mn-Ni-Mo and Ni-Mo-Cu PM steels. Pre-alloyed powder Astaloy 85Mo, diffusion alloyed powders Distaloy AQ and Distaloy AB produced by Höganäs, low carbon ferromanganese, carbonyl nickel powder T255 with three-dimensional filamentary structure and graphite CU-F have been used as the basic powders. Three mixtures with compositions of Fe-1%Mn-(0.5/1.75)%Ni-(0.5/0.85)%Mo-0.8%C and Fe-1.75%Ni-0.5%Mo-1.5%Cu-0.8%C were prepared in a Turbula mixer. Green compacts were single pressed in a steel die at 660 MPa according to PN-EN ISO 2740 standard. Sinterhardening was carried out at 1250°C in a mixture of 95% N2+5% H2 for 60 minutes. Mechanical tests (tensile, bend, hardness) and microstructural investigations were performed. Additionally, XRD and EDS analysis, fractographic investigations were carried out. The microstructures of steels investigated were mainly bainitic or bainitic-martensitic. Addition 1% Mn to Distaloy AQ based steel caused increase of tensile properties (YS from 422 to 489 MPa, UTS from 522 to 638 MPa, TRS from 901 to 1096 MPa) and decrease of plasticity (elongation from 3.65 to 2.84%).

scholarly journals Testing System for the Mechanical Properties of Small-Scale Specimens Based on 3D Microscopic Digital Image Correlation

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3530
Author(s):  
Xu Liu ◽  
Rongsheng Lu
Keyword(s):  
Mechanical Properties ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Three Dimensional ◽  
Image Correlation ◽  
Field Strain ◽  
Small Scale ◽  
Testing System ◽  
Shape Functions ◽  
Full Field

The testing of the mechanical properties of materials on a small scale is difficult because of the small specimen size and the difficulty of measuring the full-field strain. To tackle this problem, a testing system for investigating the mechanical properties of small-scale specimens based on the three-dimensional (3D) microscopic digital image correlation (DIC) combined with a micro tensile machine is proposed. Firstly, the testing system is described in detail, including the design of the micro tensile machine and the 3D microscopic DIC method. Then, the effects of different shape functions on the matching accuracy obtained by the inverse compositional Gauss–Newton (IC-GN) algorithm are investigated and the numerical experiment results verify that the error due to under matched shape functions is far larger than that of overmatched shape functions. The reprojection error is shown to be smaller than before when employing the modified iteratively weighted radial alignment constraint method. Both displacement and uniaxial measurements were performed to demonstrate the 3D microscopic DIC method and the testing system built. The experimental results confirm that the testing system built can accurately measure the full-field strain and mechanical properties of small-scale specimens.

scholarly journals An investigation of the anisotropic properties of heat-treated maraging steel grade 300 processed by laser powder bed fusion

2021 ◽  
Author(s):  
Even W. Hovig ◽  
Amin S. Azar ◽  
Klas Solberg ◽  
Knut Sørby
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Maraging Steel ◽  
Image Correlation ◽  
Powder Bed Fusion ◽  
Material Models ◽  
Powder Bed ◽  
Melt Pool ◽  
Heat Treated ◽  
Anisotropic Mechanical Properties

AbstractIn order to explore the possibilities enabled by laser beam powder bed fusion of metals (PBF-LB/M), reliable material models are necessary to optimize designs with respect to weight and stiffness. Due to the unique processing conditions in PBF-LB/M, materials often develop a dominating microstructure that leads to anisotropic mechanical properties, and thus isotropic material models fail to account for the orientation-dependent mechanical properties. To investigate the anisotropy of 18Ni300 maraging steel, tensile specimens were built in seven different orientations. The specimens were heat treated at two different conditions and tested for their tensile properties using digital image correlation (DIC) technique. The microstructure and fracture surfaces are investigated with scanning electron microscope and electron backscatter diffraction. The tensile properties are typical for the material, with a yield strength in the range of 1850 MPa to 1950 MPa, and ultimate tensile strength in the range of 1900 MPa to 2000 MPa. The elastic modulus is 180 GPa, and the elongation at fracture is in the range of 2–6% for all specimens. The strain fields analysed with DIC reveals anisotropic straining in both the elastic and plastic parts of the flow curve for both direct ageing and solution treatment plus ageing specimens. In the former condition, the elastic anisotropy is dictated by the fraction of melt pool boundaries on the transverse surfaces of the specimens. When the material is solution treated prior to ageing, the melt pool boundary effect was supressed.

scholarly journals Microstructure, Texture and Mechanical Properties of Mg-6Sn Alloy Processed by Differential Speed Rolling

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 83
Author(s):  
Kamil Majchrowicz ◽  
Paweł Jóźwik ◽  
Witold Chromiński ◽  
Bogusława Adamczyk-Cieślak ◽  
Zbigniew Pakieła
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Rolling Direction ◽  
Speed Ratio ◽  
Basal Texture ◽  
Electron Backscattered Diffraction ◽  
Normal Anisotropy ◽  
Average Grain Size ◽  
Differential Speed Rolling ◽  
Differential Speed

The effect of shear deformation introduced by differential speed rolling (DSR) on the microstructure, texture and mechanical properties of Mg-6Sn alloy was investigated. Mg-6Sn sheets were obtained by DSR at speed ratio between upper and lower rolls of R = 1, 1.25, 2 and 3 (R = 1 refers to symmetric rolling). The microstructural and textural changes were investigated by electron backscattered diffraction (EBSD) and XRD, while the mechanical performance was evaluated based on tensile tests and calculated Lankford parameters. DSR resulted in the pronounced grain refinement of Mg-6Sn sheets and spreading of basal texture as compared to conventionally rolled one. The average grain size and basal texture intensity gradually decreased with increasing speed ratio. The basal poles splitting to transverse direction (TD) or rolling direction (RD) was observed for all Mg-6Sn sheets. For the as-rolled sheets, YS and UTS increased with increasing speed ratio, but a significant anisotropy of strength and ductility between RD and TD has been observed. After annealing at 300 °C, Mg-6Sn sheets became more homogeneous, and the elongation to failure was increased with higher speed ratios. Moreover, the annealed Mg-6Sn sheets were characterized by a very low normal anisotropy (0.91–1.16), which is normally not achieved for the most common Mg-Al-Zn alloys.

Effect of Compression with Oscillatory Torsion Processing on Structure and Properties of Cu

2011 ◽  
Vol 674 ◽  
pp. 129-134 ◽  
Author(s):  
Kinga Rodak ◽  
Jacek Pawlicki ◽  
Krzysztof Radwański ◽  
Rafal M. Molak
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Grain Size ◽  
Subgrain Size ◽  
Strength Properties ◽  
Image Correlation ◽  
Compression Rate ◽  
Initial State ◽  
Electron Backscattered Diffraction ◽  
Average Grain Size

In this study, commercial Cu was subjected to plastic deformation by compression with oscillatory torsion. Different deformation parameters were adopted to study their effects on the microstructure and mechanical properties of Cu. The deformed microstructure was characterized by using scanning electron microscopy (SEM) equipment with electron backscattered diffraction (EBSD) facility and scanning transmission electron microscopy (STEM). The mechanical properties were determined on an MTS QTest/10 machine equipped with digital image correlation. Can be found, that process performed at high compression rate and high torsion frequency is recommended for the refining grain size. The size of structure elements: average grain size (D) and subgrain size (d) reached 0.42 m and 0.30 m respectively, and the fraction of high angle boundaries was 35%, when the sample was deformed at a torsion frequency f= 1.6 Hz and compression rate v=0.04 mm/s. Deformation at these parameters leads to an improvement in strength properties. The strength properties are about two times greater than the initial state.

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