scholarly journals The Effect of Material Properties on the Accuracy of Superplastic Tensile Test

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1353
Author(s):  
Sergey Aksenov ◽  
Vadim Mikolaenko
Keyword(s):  
Tensile Test ◽  
Material Properties ◽  
Material Flow ◽  
Tensile Testing ◽  
Flow Behavior ◽  
Effective Strain ◽  
Tensile Tests ◽  
Input Material ◽  
The Difference ◽  
Characterization Of Materials

Tensile testing is widely used for the mechanical characterization of materials subjected to superplastic deformation. At the same time, it is known that the obtained flow data are affected by specimen geometry. Thus, they characterize the specimen rather than the material. This work provides the numerical analysis aimed to study how the material flow behavior affects the results of tensile tests. The simulations were performed by the finite element method in Abaqus software, utilizing user-defined procedures for calculation of forces acting on the crossheads. The accuracy of tensile testing is evaluated by the difference between the input material flow behavior specified in the simulations and the output one, obtained by the standard ASTM E2448 procedure based on the predicted forces. The results revealed that the accuracy of the superplastic tensile test is affected by the material properties. Even if the material flow behavior follows the Backofen power law, which is invariant for the effective strain, the output stress–strain curves demonstrate significant strain hardening and softening effects. The relation between the basic superplastic characteristics and the tensile test errors is described and analyzed.

scholarly journals Tensile Testing with Cyclic Strain Holding to Analyze Dynamic Recrystallization of Pure Lead

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Mayu Muramatsu ◽  
Motomichi Koyama ◽  
Ikumu Watanabe
Keyword(s):  
Dynamic Recrystallization ◽  
Tensile Testing ◽  
Cyclic Strain ◽  
Tensile Tests ◽  
Pure Lead ◽  
Factors Affecting ◽  
Before And After ◽  
Dynamic Recrystallization Behavior ◽  
The Difference ◽  
Strain Responses

We analyzed the dynamic recrystallization of pure lead by tensile testing with cyclic strain holding at room temperature. The specimens were held at an identical strain and subsequently reloaded, providing the strength before and after the strain holding process. The difference in strength enables factors affecting dynamic recrystallization behavior to be analyzed through mechanical testing. For instance, the effects of strain rate on dynamic recrystallization were analyzed by comparing the results obtained from tensile tests with and without strain holding. This experimental technique demonstrated some parts of contribution of elastic strain, dynamic recovery, dynamic recrystallization, and necking to stress-strain responses.

scholarly journals The influence of sample geometry and size on porcine aortic material properties from uniaxial tensile tests using custom-designed tissue cutters, clamps and molds

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0244390
Author(s):  
Ming Pei ◽  
Donghua Zou ◽  
Yong Gao ◽  
Jianhua Zhang ◽  
Ping Huang ◽  
...  
Keyword(s):  
Material Properties ◽  
Tensile Testing ◽  
Tensile Tests ◽  
Optimal Choice ◽  
The Other ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Uniaxial Tensile Testing ◽  
Dog Bone ◽  
Weibull Theory

The aim of this study was to identify the influence of specimen geometry and size on the results of aortic uniaxial tensile tests using custom-designed tissue cutters, clamps and molds. Six descending thoracic aortas from pigs were used for rectangular sample tests, in which the circumferential and axial specimens had widths of 6 mm, 8 mm and 10 mm. The other six aortas were used for the dog-bone-shaped sample tests and were punched into circumferential, axial and oblique specimens with widths of 2 mm, 4 mm and 6 mm. We performed uniaxial tensile tests on the specimens and compared the test results. The results showed that mid-sample failure occurred in 85.2% of the dog-bone-shaped specimens and in 11.1% of the rectangular samples, which could be caused by Saint-Venant’s principle. Therefore, rectangular specimens were not suitable for aortic uniaxial tensile testing performed until rupture. The results also showed that the size effect of the aorta conformed to Weibull theory, and dog-bone-shaped specimens with a width of 4 mm were the optimal choice for aortic uniaxial tensile testing performed until rupture.

Influence of Number of Passes in ECAP on Superplastic Behavior in a Magnesium Alloy

2008 ◽  
Vol 584-586 ◽  
pp. 170-175 ◽  
Author(s):  
Roberto B. Figueiredo ◽  
Terence G. Langdon
Keyword(s):  
Strain Rate ◽  
Tensile Testing ◽  
Flow Behavior ◽  
Rate Sensitivity ◽  
Initial Strain Rate ◽  
Tensile Tests ◽  
Superplastic Behavior ◽  
Angular Pressing ◽  
Zk60 Alloy ◽  
Number Of Passes

Tensile tests were carried out at 473 K with initial strain rate of 10-4 s-1 in samples of a ZK60 alloy (Mg-5.5% Zn-0.5% Zr) processed by different number of passes using Equal-Channel Angular Pressing (ECAP). The measured superplastic elongations ranged from ~930% to a record of ~3050%. The flow behavior was found to vary with the number of passes of ECAP. It is shown that strain-hardening due to grain growth and the evolution of the strain rate sensitivity with the strain determines the flow behavior and final elongations. The results are consistent with theories of plastic flow in tensile testing.

Influence of ECAR Processing on OFHC Cu Material Properties

2010 ◽  
Vol 667-669 ◽  
pp. 133-137 ◽  
Author(s):  
Tibor Kvačkaj ◽  
Michal Kvačkaj ◽  
Volodymir Stoyka ◽  
Robert Kočiško ◽  
Jana Bidulská ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Material Properties ◽  
Effective Strain ◽  
Cold Drawing ◽  
Tensile Tests ◽  
Experimental Methods ◽  
Effective Normal Stress ◽  
Mathematical Simulations ◽  
Deform 3D

The influence of severe plastic deformation (SPD) on distribution of effective stresses, effective strains and temperatures during equal channel angular rolling (ECAR) process is mathematically simulated. Effect of ECAR processing on substructural and mechanical properties of oxygen free high conductivity (OFHC) Cu material is investigated too. Mathematical simulations in software DEFORM-3D, ECAR technology, tensile tests, EBSD analysis were used as experimental methods. Mathematical simulations of first ECAR pass referred on following results: effective normal stress had low heterogeneity with value 385 MPa, effective strain was distinguished with high heterogeneity in cross section of sample (φ=1,5-3) and temperature in deformation zone achieved value 150 °C. Mechanical properties after cold drawing were: Rp0,2 = 217 MPa, Rm = 260 MPa, Z = 63 % and after sixth ECAR pass were: Rp0,2 = 412 MPa, Rm = 426 MPa, Z = 72 %. From experiments is resulting the stabilization of mechanical properties after fourth ECAR pass were obtained.

scholarly journals Novel Tensile Test Jig and Mechanical Properties of WC-Co Synthesized by SHIP and HIP Process

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 884
Author(s):  
A-Ra Jo ◽  
Ji-Seob An ◽  
Sun-Hyung Kim ◽  
Myeong-Sik Jeong ◽  
Young-Hoon Moon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Tensile Testing ◽  
Hot Isostatic Pressing ◽  
High Strength ◽  
Tensile Tests ◽  
Isostatic Pressing ◽  
Manufacturing Method ◽  
Axial Tensile ◽  
Co Alloys

Tungsten carbide-cobalt (WC-Co) alloys have various mechanical properties according to their Co content and manufacturing method. High-strength materials such as WC-Co alloys are usually manufactured using various sintering methods. In this study, WC-Co was compared according to the Co content and manufacturing method using the sinter-hot isostatic pressing process. Furthermore, an additional test was performed to investigate the effect of post-hot isostatic pressing (HIP) treatment on the mechanical properties. To compare tensile strength, threaded end and shoulder end specimens are generally applied in axial tensile testing with hard metals. However, it is extremely difficult to shape WC-Co by machining. A tensile testing jig for a shoulder end specimen is, therefore, proposed. Tensile tests were conducted using the proposed jig, and microstructure, hardness, and impact tests were carried out to compare the mechanical properties. The microstructure evolution was obtained by decreasing the Co content and applying the HIP treatment, resulting in changes in Young’s modulus and strength. The results indicated that the proposed jig of the axial tensile test could be applied to the extremely hard WC-Co, and the mechanical properties of WC-Co could be modified by the Co content and HIP treatment control.

Hot Tensile Testing

2004 ◽  
pp. 209-238
Keyword(s):  
Tensile Test ◽  
Tensile Testing ◽  
Tensile Deformation ◽  
Local Stress ◽  
Tensile Tests ◽  
Cavity Nucleation ◽  
Testing Procedures ◽  
Tension Testing ◽  
Local Stress State

Abstract This chapter focuses on short-term tensile testing at high temperatures. It emphasizes one of the most important reasons for conducting hot tensile tests, the determination of the hot working characteristics of metallic materials. Two types of hot tensile tests are discussed in this chapter, namely, the Gleeble test and the conventional isothermal hot-tensile test. The discussion covers equipment used and testing procedures for the Gleeble test and isothermal hot tensile test, along with information on hot ductility and strength data from these tests. The chapter describes the mathematical analysis of the isothermal hot tensile test, which is based on a description of the local stress state during tension testing and some form of numerical calculation. It also describes three often-overlapping stages of cavitation during tensile deformation, namely, cavity nucleation, growth of individual cavities, and cavity coalescence.

scholarly journals Effect of Modified Pin Profile and Process Parameters on the Friction Stir Welding of Aluminum Alloy 6061-T6

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
J. C. Verduzco Juárez ◽  
G. M. Dominguez Almaraz ◽  
R. García Hernández ◽  
J. J. Villalón López
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Alloy 6061 ◽  
Alloy 6061

This work deals with the effect of a new “bolt-head” pin profile on the friction stir welding performance of the aluminum alloy 6061-T6, compared to traditional pin profiles. Friction stir welding parameters such as the tool rotation speed and the welding speed were investigated together with the different pin profiles; the results show that the new “bolt-head” pin profile leads to better mechanical properties of welded specimens. The pin profiles used in this work were the straight square (SS), straight hexagon (SH), taper cylindrical (TC), and the straight hexagon “bolt-head” (SHBH). It was found that the last pin profile improves the material flow behavior and the uniform distribution of plastic deformation and reduces the formation of macroscopic defects on the welded zone. Mechanical tensile tests on welded specimens were performed to determine the tensile strength: the specimens welded with the SHBH pin profile have shown the highest mechanical properties. An approach is presented for material flow on this aluminum alloy using the SHBH pin profile, which is related to the improvement on the resulting mechanical properties.

Diagnostics of Material Properties of Steel Sheets from the Tensile Test Record

2015 ◽  
Vol 669 ◽  
pp. 142-149
Author(s):  
Jozef Kmec ◽  
Erika Fechová
Keyword(s):  
Numerical Simulation ◽  
Computer Simulation ◽  
Tensile Test ◽  
Material Properties ◽  
Material Model ◽  
Material Parameters ◽  
Steel Sheets ◽  
Input Material ◽  
Test Record

Nowadays it is not possible to predict material properties such as stampability and their behaviour during pressing at certain conditions without computer simulation. Reliability and accuracy of the results of numerical simulation depend on accuracy of used material model and completeness of input material parameters. The paper mainly deals with diagnostics of material properties of steel sheets from the tensile test record.

RELATIVE MECHANICAL PROPERTIES OF SURGICAL WIRES AND CABLES USED IN SPINAL FIXATION AND THE GRIPPING TECHNIQUES USED FOR THEIR TENSILE TESTS

2006 ◽  
Vol 10 (01) ◽  
pp. 37-46
Author(s):  
Vaibhav Krishna ◽  
Siaw Meng Chou
Keyword(s):  
Stainless Steel ◽  
Tensile Test ◽  
Material Properties ◽  
Steel Wire ◽  
Spinal Instrumentation ◽  
Tensile Tests ◽  
Stainless Steel Wire ◽  
Spinal Fixation ◽  
Steel Cable ◽  
Premature Failure

Surgical wires and cables have been extensively used for spinal fixation. They are used in conjunction with spinal instrumentation to stabilize the spine. This paper seeks to explore the best method for clamping stainless steel wire and stainless steel cable for tensile test and to compare the relative mechanical material properties of Sofamor Danek Axis (SDA) stainless steel wire with SDA stainless steel cable using the most suitable gripping method found, in order to determine which is mechanically more superior/effective for spinal fixation. Utilization of mechanical grips with sandpaper lining has been found to be an effective method for clamping wires for tensile test. For cables, the problem of stress concentration and premature failure during tensile test has been overcome by embedding both ends of the cable in carbon fibre.

scholarly journals Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 581
Author(s):  
Kai Li ◽  
Zhenyu Zhao ◽  
Houming Zhou ◽  
Hao Zhou ◽  
Jie Yin ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Processing Parameters ◽  
Surface Finishing ◽  
Polished Surface ◽  
Laser Polishing ◽  
Starting Position ◽  
Double Spiral ◽  
The Difference ◽  
Thermocapillary Forces ◽  
Surface Morphologies

As a surface finishing technique for rapid remelting and re-solidification, laser polishing can effectively eliminate the asperities so as to approach the feature size. Nevertheless, the polished surface quality is significantly sensitive to the processing parameters, especially with respect to melt hydrodynamics. In this paper, a transient two-dimensional model was developed to demonstrate the molten flow behavior for different surface morphologies of the Ti6Al4V alloy. It is illustrated that the complex evolution of the melt hydrodynamics involving heat conduction, thermal convection, thermal radiation, melting and solidification during laser polishing. Results show that the uniformity of the distribution of surface peaks and valleys can improve the molten flow stability and obtain better smoothing effect. The high cooling rate of the molten pool resulting in a shortening of the molten lifetime, which prevents the peaks from being removed by capillary and thermocapillary forces. It is revealed that the mechanism of secondary roughness formation on polished surface. Moreover, the double spiral nest Marangoni convection extrudes the molten to the outsides. It results in the formation of expansion and depression, corresponding to nearby the starting position and at the edges of the polished surface. It is further found that the difference between the simulation and experimental depression depths is only about 2 μm. Correspondingly, the errors are approximately 8.3%, 14.3% and 13.3%, corresponding to Models 1, 2 and 3, respectively. The aforementioned results illustrated that the predicted surface profiles agree reasonably well with the experimentally measured surface height data.

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