Modeling Bake Hardening Effects in Steel Sheets—Application to Dent Resistance

This study is dedicated to the experimental characterisation and phenomenological modeling of the bake hardening effect of a thin steel sheet, to predict the static dent resistance and perform an experimental validation on a bulged part. In a first step, rectangular samples are submitted to a thermo-mechanical loading to characterise the bake hardening magnitude in tension. A three-step procedure is considered, involving first a pre-strain in tension up to several values followed by unloading. Secondly, a heat treatment during a fixed time and a given temperature is performed, and finally, a reloading in tension in the same direction as the pre-strain is applied. Then, a specific device is developed to perform dent tests on a bulged specimen, to evaluate the influence of bake hardening on the dent resistance. A three-step procedure is also considered, with a pre-strain applied with a hydraulic bulge test followed by a heat treatment and then static dent test at the maximum dome height. An original phenomenological model is proposed to represent the yield stress increase after the heat treatment and the second reloading. Material parameters are identified from the tensile tests and are input data to a finite element model. The numerical prediction of the load evolution during the dent test is then compared with experimental data and shows an overall good correlation.

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Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽

10.3390/met11060875 ◽

2021 ◽

Vol 11 (6) ◽

pp. 875

Author(s):

Jie Wu ◽

Yuri Hovanski ◽

Michael Miles

Keyword(s):

Experimental Data ◽

Finite Element ◽

Numerical Model ◽

Plastic Strain ◽

Finite Element Model ◽

Equivalent Plastic Strain ◽

Element Model ◽

Dome Height ◽

Tailor Welded Blanks ◽

Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

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Finite Element Method modeling of Additive Manufactured Compressor Wheel

Journal of The Institution of Engineers (India) Series D ◽

10.1007/s40033-021-00251-8 ◽

2021 ◽

Author(s):

Márton Tamás Birosz ◽

Mátyás Andó ◽

Sudhanraj Jeganmohan

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Finite Element Method Simulation ◽

Element Model ◽

Tensile Tests ◽

Raw Material ◽

Isotropic Hardening ◽

Compressor Wheel ◽

Material Extrusion ◽

Element Method

AbstractDesigning components is a complex task, which depends on the component function, the raw material, and the production technology. In the case of rotating parts with higher RPM, the creep and orientation are essential material properties. The PLA components made with the material extrusion process are more resistant than VeroWhite (material jetting) and behave similarly to weakly cross-linked elastomers. Also, based on the tensile tests, Young’s modulus shows minimal anisotropy. Multilinear isotropic hardening and modified time hardening models are used to create the finite element model. Based on the measurements, the finite element method simulation was identified. The deformation in the compressor wheel during rotation became definable. It was concluded that the strain of the compressor wheel manufactured with material extrusion technology is not significant.

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Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

High Temperature Materials and Processes ◽

10.1515/htmp-2019-0050 ◽

2019 ◽

Vol 38 (2019) ◽

pp. 892-896 ◽

Cited By ~ 1

Author(s):

Süleyman Tekeli ◽

Ijlal Simsek ◽

Dogan Simsek ◽

Dursun Ozyurek

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Solid Solution ◽

Tensile Strength ◽

Tensile Tests ◽

Solution Temperature ◽

T6 Heat Treatment ◽

Microstructure And Mechanical Properties ◽

Different Temperatures

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

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Influence of Heat Treatment on Microstructure and Mechanical Properties of Selective Laser Melted TiAl6V4 Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.284.615 ◽

2018 ◽

Vol 284 ◽

pp. 615-620 ◽

Cited By ~ 2

Author(s):

R.M. Baitimerov ◽

P.A. Lykov ◽

L.V. Radionova

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Selective Laser Melting ◽

Room Temperature ◽

Base Alloy ◽

Tensile Tests ◽

Heat Treatments ◽

Laser Melting ◽

Microstructure And Mechanical Properties ◽

Treatment Procedures

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.

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Microstructural Effect and Material Homogenization of Thermal-Hydroforming Magnesium Alloy Tubes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.465.459 ◽

2011 ◽

Vol 465 ◽

pp. 459-462 ◽

Cited By ~ 1

Author(s):

Lin Wang ◽

Luen Chow Chan ◽

Ting Fai Kong

Keyword(s):

Heat Treatment ◽

Magnesium Alloy ◽

Tensile Tests ◽

Heat Treatment Condition ◽

Material Strength ◽

Forming Process ◽

Engineering Strain ◽

Treatment Conditions ◽

Metal Forming Process ◽

Microstructural Effect

The microstrctural evolution pre and post heat treatment is critical to achieve a successful product for metal forming process. This paper aims to investigate the microstructual effect of the magnesium alloy tubes undergone various heat treatment conditions to achieve material homogenization. The heat treatment conditions under various periods of time (1, 2, 6, 12 and 30 hours) at 400 °C were employed to investigate the microstructural effect on hydroforming magnesium tubes. The greatly reduced impurity embedded in grain boundaries and more uniform grain sizes do indicate the improvement of material strength and ductility. To validate the conclusion, corresponding tensile tests at the different temperatures (20 °C and 200 °C) were carried out. The increased engineering strain in two directions (hoop and longitudinal) implies that the microstructural evolution is unquestionably useful to enhance the ductility of the magnesium tubes. Subsequently, the tubes after optimal heat treatment condition at 400 °C for 6 hours were used to further carry out the thermal hydroforming process for validation. The defect-free hydroformed tubes were produced under the same working condition, which is unable to be achieved for tubes without the heat-treatment process.

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A Comparative Study on Hydraulic Bulge Testing and Analysis Methods

ASME 2008 International Manufacturing Science and Engineering Conference, Volume 1 ◽

10.1115/msec_icmp2008-72238 ◽

2008 ◽

Cited By ~ 4

Author(s):

Eren Billur ◽

Muammer Koc¸

Keyword(s):

Flow Stress ◽

Optical Measurement ◽

Measurement Techniques ◽

Material Behavior ◽

Biaxial Stress ◽

Dome Height ◽

Bulge Test ◽

Analysis Methods ◽

Bulge Testing ◽

Hydraulic Bulge

Hydraulic bulge testing is a material characterization method used as an alternative to tensile testing with the premise of accurately representing the material behavior to higher strain levels (∼70% as appeared to ∼30% in tensile test) in a biaxial stress mode. However, there are some major assumptions (such as continuous hemispherical bulge shape, thinnest point at apex) in hydraulic bulge analyses that lead to uncertainties in the resulting flow stress curves. In this paper, the effect of these assumptions on the accuracy and reliability of flow stress curves is investigated. The goal of this study is to determine the most accurate method for analyzing the data obtained from the bulge testing when continuous and in-line thickness measurement techniques are not available. Specifically, in this study the stress-strain relationships of two different materials (SS201 and Al5754) are obtained based on hydraulic bulge test data using various analysis methods for bulge radius and thickness predictions (e.g., Hill’s, Chakrabarty’s, Panknin’s theories, etc.). The flow stress curves are calculated using pressure and dome height measurements and compared to the actual 3-D strain measurement from a stereo optical and non-contact measurement system ARAMIS. In addition, the flow stress curves obtained from stepwise experiments are compared with the ones from above methods. Our findings indicate that Enikeev’s approach for thickness prediction and Panknin’s approach for bulge radius calculation result in the best agreement with both stepwise experiment results and 3D optical measurement results.

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An Improved Control Arm Design for a Commercial Vehicle

10.52460/issc.2021.036 ◽

2021 ◽

Author(s):

Sinan Yıldırım ◽

Ufuk Çoban ◽

Mehmet Çevik

Keyword(s):

Finite Element ◽

Cost Effective ◽

Element Model ◽

Tensile Tests ◽

The Body ◽

Von Mises Stress ◽

Driving Safety ◽

Design Development ◽

Element Analysis ◽

Von Mises

Suspension linkages are one of the fundamental structural elements in each vehicle since they connect the wheel carriers i.e. axles to the body of the vehicle. Moreover, the characteristics of suspension linkages within a suspension system can directly affect driving safety, comfort and economics. Beyond these, all these design criteria are bounded to the package space of the vehicle. In last decades, suspension linkages have been focused on in terms of design development and cost reduction. In this study, a control arm of a diesel public bus was taken into account in order to get the most cost-effective design while improving the strength within specified boundary conditions. Due to the change of the supplier, the control arm of a rigid axle was redesigned to find an economical and more durable solution. The new design was analyzed first by the finite element analysis software Ansys and the finite element model of the control arm was validated by physical tensile tests. The outputs of the study demonstrate that the new design geometry reduces the maximum Von Mises stress 15% while being within the elastic region of the material in use and having found an economical solution in terms of supplier’s criteria.

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Comparison of Different Heat Treatment Processes of Selective Laser Melted 316L Steel Based on Analysis of Mechanical Properties

Materials ◽

10.3390/ma13173805 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3805 ◽

Cited By ~ 3

Author(s):

Janusz Kluczyński ◽

Lucjan Śnieżek ◽

Krzysztof Grzelak ◽

Artur Oziębło ◽

Krzysztof Perkowski ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Hot Isostatic Pressing ◽

Tensile Tests ◽

Fracture Analysis ◽

Image Correlation ◽

Treatment Processes ◽

Different Types ◽

316L Steel ◽

Precipitation Heat

In this study, we analyzed the mechanical properties of selectively laser melted (SLM) steel obtained via different modifications during and after the manufacturing process. The aim was to determine the effects of precipitation heat treatment on the mechanical properties of elements additively manufactured using three different process parameters. Some samples were additionally obtained using hot isostatic pressing (HIP), while some were treated using two different types of heat treatment and a combination of those two processes. From each manufactured sample, a part of the material was taken for structural analysis including residual stress analysis and microstructural investigations. In the second part of the research, the mechanical properties were studied to define the scleronomic hardness of the samples. Finally, tensile tests were conducted using a digital image correlation (DIC) test and fracture analysis. The treated samples were found to be significantly elongated, thus indicating the advantages of using precipitation heat treatment. Additionally, precipitation heat treatment was found to increase the porosity of samples, which was the opposite compared to HIP-treated samples.

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Development of Precipitation Hardening Parameters for High Strength Alloy AA 7068

Materials ◽

10.3390/ma13040918 ◽

2020 ◽

Vol 13 (4) ◽

pp. 918

Author(s):

Julia Osten ◽

Benjamin Milkereit ◽

Michael Reich ◽

Bin Yang ◽

Armin Springer ◽

...

Keyword(s):

Heat Treatment ◽

Cooling Rate ◽

Maximum Yield ◽

High Strength ◽

Tensile Tests ◽

Age Hardening ◽

Scanning Calorimetry ◽

Cooling Rates ◽

Critical Cooling Rate ◽

Kinetics Of

The mechanical properties after age hardening heat treatment and the kinetics of related phase transformations of high strength AlZnMgCu alloy AA 7068 were investigated. The experimental work includes differential scanning calorimetry (DSC), differential fast scanning calorimetry (DFSC), sophisticated differential dilatometry (DIL), scanning electron microscopy (SEM), as well as hardness and tensile tests. For the kinetic analysis of quench induced precipitation by dilatometry new metrological methods and evaluation procedures were established. Using DSC, dissolution behaviour during heating to solution annealing temperature was investigated. These experiments allowed for identification of the appropriate temperature and duration for the solution heat treatment. Continuous cooling experiments in DSC, DFSC, and DIL determined the kinetics of quench induced precipitation. DSC and DIL revealed several overlapping precipitation reactions. The critical cooling rate for a complete supersaturation of the solid solution has been identified to be 600 to 800 K/s. At slightly subcritical cooling rates quench induced precipitation results in a direct hardening effect resulting in a technological critical cooling rate of about 100 K/s, i.e., the hardness after ageing reaches a saturation level for cooling rates faster than 100 K/s. Maximum yield strength of above 600 MPa and tensile strength of up to 650 MPa were attained.

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Yield Characteristics of a Twill Dutch Woven Wire Mesh Via Experiments and Numerical Modeling

Journal of Applied Mechanics ◽

10.1115/1.4007793 ◽

2013 ◽

Vol 80 (4) ◽

Cited By ~ 3

Author(s):

Steven M. Kraft ◽

Ali P. Gordon

Keyword(s):

Heat Treatment ◽

Numerical Modeling ◽

Tensile Tests ◽

Woven Fabrics ◽

Wire Mesh ◽

Uniaxial Tensile ◽

3D Numerical Modeling ◽

Stainless Steel 316L ◽

Treatment Development ◽

Woven Structures

Woven structures are steadily emerging as excellent reinforcing components in composite materials. Metallic woven meshes, unlike most woven fabrics, show high potential for strengthening via classical methods such as heat treatment. Development of strengthening processes for metallic woven materials, however, must account not only for behavior of the constituent wires, but also for the interactions between contacting wires. Yield behavior of a 325 × 2300 stainless steel 316L (SS316L) twill dutch woven wire mesh is analyzed via experimental data and 3D numerical modeling. The effects of short dwell-time heat treatment on the mechanical properties of this class of materials is investigated via uniaxial tensile tests in the main weave orientations. Scanning electron microscopy (SEM) is employed to investigate the effects of heat treatment on contacting wire interaction, prompted by observations of reduced ductility in the macrostructure of the mesh. Finally, the finite element method (FEM) is used to simulate the accumulation of plastic deformation in the mesostructure of the mesh, investigating how this wire level plasticity ultimately affects global material yielding.

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