Semi-Solid Deformation of Al-Fe Alloy Prepared by Electromagnetic Stirring

2010 ◽  
Vol 152-153 ◽  
pp. 726-733 ◽  
Author(s):  
Bo Liu ◽  
Xiao Guang Yuan ◽  
Hong Jun Huang ◽  
Shao Hua Zhang
Keyword(s):  
Strain Rate ◽  
Solid Fraction ◽  
Deformation Temperature ◽  
Strain Softening ◽  
Testing Machine ◽  
Materials Testing ◽  
Solid Alloy ◽  
Solid Deformation ◽  
Semi Solid ◽  
Peak Value

The semi-solid compression behaviors and the microstructure of Al-Fe alloy prepared by electromagnetic stirred were investigated in the strain rate range of 5×10-3 s-1 to 5×10-1 s-1 and the temperature range of 610 to 640°C on INSTRON-5500R materials testing machine. The experimental results showed that, during the semi-solid deformation of Al-Fe alloy，the peak value of true stress decreased with elevating deformation temperature. As the deformation increased, the stress peak value of the high solid fraction alloy was tending upwards, and that of the low solid fraction was tending downwards. The peak increased with increasing the strain rate. Al-Fe alloy was sensitive to strain rate during semi-solid compression. The strain softening phenomenon would happen. The smaller strain rate, the longer softening process, the stress falling was more slowly. The strain softening was a reason that the semi-solid alloy structure was instability during deformation. The semi-solid deformational behaviors of Al-Fe alloy was bound up with deformation temperature, strain rate, and deforming extent.

Globule-Globule Interactions during Deformation in Semi-Solid Al-Cu Using Time-Resolved X-Ray Tomography

2012 ◽  
Vol 192-193 ◽  
pp. 179-184
Author(s):  
Kristina Maria Kareh ◽  
Peter D. Lee ◽  
Christopher M. Gourlay
Keyword(s):  
Solid Fraction ◽  
Three Dimensional ◽  
Solid Alloy ◽  
Three Dimensional Imaging ◽  
Time Resolved ◽  
X Ray ◽  
Analysis Techniques ◽  
Solid Deformation ◽  
Fundamental Understanding ◽  
Semi Solid

Optimising semi-solid processing and accurately modelling semi-solid deformation requires a fundamental understanding of the globule-scale mechanisms that cause the macroscopic rheological response. In this work, apparatus and analysis techniques are being developed for the time-resolved, three-dimensional imaging of semi-solid alloy deformation. This paper overviews synchrotron X-ray tomography results on globular Al-15wt%Cu deformed at 0.7 solid fraction using extrusion. The globule-globule interactions in response to load were quantified in terms of the response of individual globules with respect to globule translation, rotation, and deformation. The potential of time-resolved X-ray tomography in the study of semi-solid alloy deformation is then discussed.

Deformation Characteristics and Mechanism of Martensitic Stainless Steel during Thixoforming

2014 ◽  
Vol 217-218 ◽  
pp. 195-200
Author(s):  
Ren Bo Song ◽  
Ya Ping Li ◽  
Yong Jin Wang ◽  
Cui Qing Zhao
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Martensitic Stainless Steel ◽  
Testing Machine ◽  
Functionally Graded ◽  
Deformation Resistance ◽  
Liquid Region ◽  
Deformation Characteristics ◽  
Semi Solid

Semi-solid billet of 9Cr18 martensitic stainless steel with globular grains was made by a wavelike sloping plate experimental device, and hot compression tests were carried out in the semi-solid state of 9Cr18 semi-solid billet on Gleeble-1500 thermal simulation testing machine at the temperatures of 1250°C ~1300°C and the strain rates of 0.1 s-1~5.0 s-1to investigate the effects of thixoforming parameters on its deformation characteristics and mechanism. According to the true stress-strain curves obtained from the test, the influence of deformation temperature and strain rate on 9Cr18 semi-solid billet deformation resistance was investigated, and the deformation resistance model of specimen with coexistence of solid and liquid phases was established. In this paper, it was found that deformation mechanism changed because of different deformation temperature and strain rate. Dynamic recrystallization occured at 1250°C in different phases separately. So that big fine recrystallized grains were achieved at the soft primary austenite region while small recrystallized grains were achieved at the hard solidified liquid region. The melted metal would be extruded from the centre of the specimen to the free surface completely when the temperature was higher than 1275°C. And then specimen became FGM (functionally graded materials), with phases and properties graded distribution perpendicular to the stress direction. When thixoforming temperature reached 1300 °C, martensitic transformation occurred after rapid cooling. The mathematics models of the relation between stress and temperatures, fraction of solid, deformation rates and deformation degree of 9Cr18 semi-solid billet were regressed and established based on the dates attained from the compression deformation experiments. The R value was 0.991, and the RMSE value was 3.57.

Influence of plastic deformation temperature on the structure and mechanical properties of low-alloy copper alloys with Co, Ni and B

2017 ◽  
Vol 84 (2) ◽  
pp. 49-57 ◽  
Author(s):  
B. Grzegorczyk ◽  
W. Ozgowicz
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Strain Rate ◽  
Minimum Temperature ◽  
Deformation Temperature ◽  
Tensile Testing ◽  
Copper Alloys ◽  
Testing Machine ◽  
Temperature Range ◽  
Ductility Minimum

Purpose: This work presents the influence of chemical composition and plastic deformation temperature of CuCoNi and CuCoNiB as well as CuCo2 and CuCo2B alloys on the structure, mechanical properties and, especially on the inter-crystalline brittleness phenomenon and ductility minimum temperature effect in tensile testing with strain rate of 1.2·10-3 s-1 in the range from 20°C to 800°C. Design/methodology/approach: The tensile test of the investigated copper alloys was realized in the temperature range of 20-800°C with a strain rate of 1.2·10-3 s–1 on the universal testing machine. Metallographic observations of the structure were carried out on a light microscope and the fractographic investigation of fracture on an electron scanning microscope. Findings: Low-alloy copper alloys such as CuCo2 and CuCo2B as well as CuCoNi and CuCoNiB show a phenomenon of minimum plasticity at tensile testing in plastic deforming temperature respectively from 500°C to 700°C for CuCo2, from 450°C to 600°C for CuCo2B and from 450°C to 600°C for CuCo2B and from 500°C to 600°C for CuCoNiB. Practical implications: In result of tensile tests of copper alloys it has been found that the ductility minimum temperature of the alloys equals to about 500°C. At the temperature of stretching of about 450°C the investigated copper alloys show maximum strength values. Originality/value: Based on the test results the temperature range for decreased plasticity of CuCoNi and CuCoNiB as well as CuCo2 and CuCo2B alloys was specified. This brittleness is a result of decreasing plasticity in a determined range of temperatures of deforming called the ductility minimum temperature.

Effect of Solid Fraction on Microstructure and Casting Faults of AZ91D Alloys in New Type Semi-Solid Injection Process

2006 ◽  
Vol 116-117 ◽  
pp. 441-444 ◽  
Author(s):  
Kenji Miwa ◽  
Rudi S. Rachmat ◽  
Takuya Tamura
Keyword(s):  
Solid Fraction ◽  
Testing Machine ◽  
Solid Particles ◽  
Casting Defects ◽  
Permanent Mold ◽  
Forming Process ◽  
Injection Process ◽  
Controlling System ◽  
New Type ◽  
Semi Solid

We have developed new type semi-solid injection process, that is, runner-less injection process. In order to investigate the effects of solid fraction on microstructure and casting defects of AZ91D in new type semi solid injection process, semi-solid forming testing machine which has the same system as a runner-less injection machine has been made on an experimental basis. Its temperature controlling system has been established to obtain the homogeneous solid-liquid coexisted state in its injection cylinder. AZ91D billets are injected into a permanent mold by this machine in the semi-solid state. A shearing in the part of nozzle of injection cylinder is the most important to reveal thixotropic property of alloy slurry in semi solid forming process by injection machine. So it needs controlling of solid fraction to affect thixotropic property. In order to decrease casting defects and hold homogeneous structure, solid fraction more over 50% is needed. But when the solid fraction increases more than 50%, primary solid particles grow coarser, and then controlling method is required to suppress coarsening. In the case of less than 50% of solid fraction, liquid part preferentially fills inside the permanent mold and alloy slurry continue to fill the mold behind alloy liquid. Then large casting defects form at the boundary of both flows.

Research on the Semi-Solid Compressive Deformation Behavior of Ti-7Cu Alloy

2016 ◽  
Vol 35 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Yongnan Chen ◽  
Chuang Luo ◽  
Jiao Wang ◽  
Yongqing Zhao ◽  
Hong Chen
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Strain Rate Range ◽  
Rate Range ◽  
Solid Deformation ◽  
Pile Up ◽  
Compressive Testing ◽  
Semi Solid ◽  
Increasing Temperature

AbstractThe semi-solid deformation behavior of Ti-7Cu titanium alloy in the temperature range of 1,223 K to 1,473 K and strain rate range of 0.005 to 5 s−1 have been investigated by hot compressive testing. The results show that the maximum and stability stresses decrease with decreasing strain rate and increasing temperature. A yielding occurred to the alloy at a higher strain rate under all experimental temperatures. The flow behaviors were described by a constitutive equation based on the Arrhenius equations and the deformation activate energies is also calculated. By comparing with microstructure of the solid deformation, the liquid in semi-solid deformation can overcome the restriction of the movement of solid particle, which reduced the dislocation pile-up during deformation and caused low deformation resistant stress.

scholarly journals Quasi-Static and Dynamic Compressive Behavior of Gum Metal: Experiment and Constitutive Model

2021 ◽  
Author(s):  
Karol Marek Golasiński ◽  
Jacek Janiszewski ◽  
Judyta Sienkiewicz ◽  
Tomasz Płociński ◽  
Maciej Zubko ◽  
...  
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Strain Softening ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Compressive Behavior ◽  
Hopkinson Pressure Bar ◽  
Softening Effect ◽  
Kink Bands ◽  
Gum Metal

AbstractThe quasi-static and high strain rate compressive behavior of Gum Metal with composition Ti-36Nb-2Ta-3Zr-0.3O (wt pct) has been investigated using an electromechanical testing machine and a split Hopkinson pressure bar, respectively. The stress–strain curves obtained for Gum Metal tested under monotonic and dynamic loadings revealed a strain-softening effect which intensified with increasing strain rate. Moreover, the plastic flow stress was observed to increase for both static and dynamic loading conditions with increasing strain rate. The microstructural characterization of the tested Gum Metal specimens showed particular deformation mechanisms regulating the phenomena of strain hardening and strain softening, namely an adiabatic shear band formed at ~ 45 deg with respect to the loading direction as well as widely spaced deformation bands (kink bands). Dislocations within the channels intersecting with twins may cause strain hardening while recrystallized grains and kink bands with crystal rotation inside the grains may lead to strain softening. A constitutive description of the compressive behavior of Gum Metal was proposed using a modified Johnson–Cook model. Good agreement between the experimental and the numerical data obtained in the work was achieved.

Influence of Si and Mg Contents on the Mechanical Behavior of Al-Mg-Si Alloys in the Semi-Solid State under Isothermal and Non-Isothermal Conditions

2011 ◽  
Vol 690 ◽  
pp. 73-76
Author(s):  
Eliane Giraud ◽  
Michel Suéry ◽  
Michel Coret
Keyword(s):  
Solid State ◽  
Aluminum Alloys ◽  
Mechanical Behavior ◽  
Solid Fraction ◽  
Solid Alloy ◽  
Isothermal Conditions ◽  
Formation Of Cracks ◽  
Semi Solid ◽  
Si Content ◽  
Mg Content

The shear behavior of aluminum alloys containing increased amounts of Si or Mg compared with the 6061 alloy has been investigated by carrying out isothermal and non-isothermal tests in the mushy state during solidification. In isothermal conditions, it is shown that (i) an increase in Mg content leads to a more resistant semi-solid alloy compared with the 6061 alloy for the same solid fraction and (ii) an increase in Si content leads to a more brittle mushy alloy. In non-isothermal conditions, stress increases continuously with decreasing temperature with the formation of cracks for some compositions. This study shows that an increase in Mg content seems to be the most appropriate solution to reduce the formation of cracks in a solidifying 6061 alloy.

Constitutive Equation of ZL201 Alloy during the Semi-Solid Thixotropic Compression

2011 ◽  
Vol 418-420 ◽  
pp. 1274-1278
Author(s):  
Shu Zhen Shang ◽  
Xiao Ling Tang ◽  
Gui Min Lu ◽  
Wan Ning Zhang ◽  
Jiao Jiao Wang
Keyword(s):  
Experimental Data ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Processing Parameters ◽  
Experimental Results ◽  
Semi Solid ◽  
The Relationship

Effects of deformation temperature and strain rate on deformation behavior of semi-solid ZL201 alloy were investigated on Gleeble3800 thermal-mechanical simulator. On basis of the experimental data of semi-solid ZL201, a model of was established to describe the relationship between the processing parameters and flow stress, which showed that the experimental results and calculation ones fitted well. The suitable conditions of this model for semi-solid ZL201 alloy were that the temperature range was 547°C-649°C and that of the strain rate was 0.1 s-1-5s-1.

Deformation Behavior of Semi-Solid ZCuSn10P1 Copper Alloy during Isothermal Compression

2016 ◽  
Vol 256 ◽  
pp. 31-38
Author(s):  
Jia Wang ◽  
Rong Feng Zhou ◽  
Han Xiao ◽  
De Hong Lu ◽  
Lu Li ◽  
...  
Keyword(s):  
Strain Rate ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Copper Alloy ◽  
Deformation Resistance ◽  
Experimental Results ◽  
Isothermal Compression ◽  
Compression Tests ◽  
Sima Process ◽  
Semi Solid

The isothermal compression tests of semi-solid ZCuSn10P1 alloy by strain induced melt activation (SIMA) process are carried out by Gleeble-1500 thermo-mechanical simulator, and the same tests are finished to samples of as-cast ZCuSn10P1 alloy. The deformation temperature respectively is 910°C, 920°C and 930°C, and the strain respectively is 0.4 and 0.6, the strain rate is 0.5s-1, 1s-1 and 10s-1. The experimental results indicate that the deformation resistance of semi-solid ZCuSn10P1 copper alloy with smaller, more uniform and rounder solid grain is about half of the as-cast ZCuSn10P1 copper alloy. The deformation resistance of ZCuSn10P1 alloy by SIMA process decreases with the deformation temperature increasing, and the deformation resistance increases with the strain rate increasing.

In Situ Study of the Altering Globule Packing-Density during Semisolid Alloy Deformation

2012 ◽  
Vol 192-193 ◽  
pp. 185-190
Author(s):  
C.M. Gourlay ◽  
T. Nagira ◽  
Kentaro Uesugi ◽  
Hideyuki Yasuda
Keyword(s):  
Solid Fraction ◽  
Packing Density ◽  
Solid Deformation ◽  
Synchrotron Radiography ◽  
Semisolid Alloy ◽  
Local Compaction ◽  
Semi Solid ◽  
The Individual ◽  
Water Saturated

Synchrotron radiography experiments are overviewed that directly image semi-solid deformation at the globule-scale. Globular Al-15Cu at 50-60% solid was deformed in direct-shear at 10-2 s-1. Deformation is shown to occur by globule rearrangement without discernible deformation of the individual globules. Globules were found to translate and rotate as quasi-discrete bodies in response to forces acting at globule-globule contacts, similar to liquid-saturated granular materials such as water-saturated sand. Rearrangement caused the globule packing-density (the solid fraction) to adjust by local compaction and local dilation of the globule assembly, and deformation is highly inhomogeneous. During shear, there was a net dilation and strain began to localize into a shear band of decreased solid fraction by the end of the experiments.

Sign in / Sign up

Export Citation Format

Share Document