scholarly journals Low-Temperature Induced Martensitic Transformation Enhancing Mechanical Properties of Metastable Fe-Ni-P Alloy

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 785
Author(s):  
Cui ◽  
Jiang ◽  
Zhang ◽  
Liu
Keyword(s):  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Low Temperature ◽  
Strain Hardening ◽  
Low Temperatures ◽  
Cryogenic Treatment ◽  
Great Promise ◽  
Compressive Yield Strength ◽  
High Plasticity ◽  
Face Centered Cubic

The metastable Fe-Ni-P alloy with phosphorus (P) solid-solution structure has been fabricated by spark plasma sintering. Its face-centered cubic (FCC) matrix without the precipitation of phosphide attains a high plasticity and an excellent strain hardening ability at room temperature. This Fe-Ni-P alloy is subjected to cryogenic treatment at various temperatures (−20 °C and −50 °C), to investigate the role of phosphorus on the microstructural evolution and mechanical properties of γ-(Fe-Ni) alloy at low temperatures. The results indicate that the addition of phosphorus can destabilize the Fe-Ni-P alloy and facilitate its martensitic transformation during cryogenic treatment. P-doping does not lead to obvious embrittlement of Fe-Ni-P alloy at low temperatures, but strengthens the alloy by promoting microstructure evolution. The Fe-Ni-P alloy has high plasticity and good strain hardening ability after treated at −20 °C, and is converted to acicular martensite structure after being treated at −50 °C, resulting in a significant increase in its hardness (433 HV) and compressive yield strength (1271 MPa). Developing this Fe-Ni-P alloy as a load-bearing component for low-temperature conditions shows great promise.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

Low-temperature martensitic transformation and deep cryogenic treatment of a tool steel

2010 ◽  
Vol 527 (26) ◽  
pp. 7027-7039 ◽  
Author(s):  
A.I. Tyshchenko ◽  
W. Theisen ◽  
A. Oppenkowski ◽  
S. Siebert ◽  
O.N. Razumov ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Low Temperature ◽  
Tool Steel ◽  
Cryogenic Treatment ◽  
Deep Cryogenic Treatment

scholarly journals Effects of Nb Addition on Microstructures and Mechanical Properties of Nbx-CoCrFeMnNi High Entropy Alloy Films

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1539
Author(s):  
Yu-Hsuan Liang ◽  
Chia-Lin Li ◽  
Chun-Hway Hsueh
Keyword(s):  
Mechanical Properties ◽  
Amorphous Phase ◽  
Compressive Yield Strength ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
Compression Tests ◽  
Alloy Films ◽  
High Entropy ◽  
Microstructures And Mechanical Properties ◽  
Nb Addition

In the present work, Nbx-CoCrFeMnNi high entropy alloy films (HEAFs, 0 to 7.2 at.% Nb) were fabricated by radio frequency (RF) magnetron co-sputtering of CoCrFeMnNi alloy and Nb targets. The effects of Nb addition on the microstructures and mechanical properties of HEAFs were systematically investigated. For Nb-free film (0 at.% Nb), the face-centered cubic (FCC) peaks were identified in the X-ray diffraction (XRD) pattern. The addition of Nb resulted in a broadening of diffraction peaks, a decrease in peak intensity, and the vanishment of high-angle peaks. Transmission electron microscope (TEM) images indicated the formation of nanotwins at low Nb concentrations, and a transition from a single phase FCC solid solution to an amorphous phase was observed with the increasing Nb concentration. The films were strengthened with an increase in Nb concentration. Specifically, the hardness characterized by nanoindentation increased from 6.5 to 8.1 GPa. The compressive yield strength and fracture strength measured from micropillar compression tests were improved from 1.08 GPs and 2.56 GPa to 2.70 GPa and 5.76 GPa, respectively, whereas the fracture strain decreased from >29.4% (no fracture) to 15.8%. Additionally, shear banding was observed in the presence of amorphous phase.

Low-Temperature (<300°C) Phosphate Ceramics from Reactive Aluminas

1989 ◽  
Vol 179 ◽  
Author(s):  
M. R. Silsbee ◽  
R. A. Steinke ◽  
D. M. Roy ◽  
D. K. Agrawal ◽  
R. Roy
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Low Temperatures ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Techniques ◽  
Exciting Potential

AbstractReactive aluminas, including rapidly calcined gibbsites, offer exciting potential for forming ceramic materials at low temperatures. New x-ray amorphous aluminas will react with water at room temperatures to form compacts with 10–50 MPa tensile strengths, via viscous slurries. The cementious behavior of these materials has been examined. The results of TGA, x-ray diffraction, SEM, mechanical properties, and other characterization techniques, as applied to these systems, will be discussed.

The Effect of Cryogenic Treatment on the Microstructure and Properties of Ti-6Al-4V Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 899-903 ◽  
Author(s):  
Kai Xuan Gu ◽  
Zhi Qiang Li ◽  
Jun Jie Wang ◽  
Yuan Zhou ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Low Temperature ◽  
Fracture Surface ◽  
Cross Section ◽  
Cryogenic Treatment ◽  
Great Influence ◽  
Microstructure And Properties ◽  
Scanning Electron

The effect of cryogenic treatment on the microstructure and properties of Ti-6Al-4V has been studied in this paper. The program controlled SLX cryogenic box was used to conduct the cryogenic treatment and the subsequent low temperature temper. The scanning electron microscope was used to study the morphology of microstructure and fracture surface. As the results show that the cryogenic treatment increases the elongation of Ti-6Al-4V from 16.5 percent to 24.5 percent, at the same time, the strength increases slightly, this indicates that cryogenic treatment can improve the comprehensive mechanical properties. The microstructure measurement revealed that there is a tendency of reduction in the precipitated particles after cryogenic treatment. The cross section is flat and the size of dimples is more uniform. It is concluded that the change in the precipitation particle had a great influence in the mechanical properties.

Effect of Cryogenic Treatment on Mechanical Properties and Microstructures of 3102 Al-Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 845-848 ◽  
Author(s):  
Xian Quan Jiang ◽  
Ning Li ◽  
Hong He ◽  
Xiu Jin Zhang ◽  
Chun Chi Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Breaking Strength ◽  
Cryogenic Treatment ◽  
Al Alloy ◽  
Deep Cryogenic Treatment ◽  
Transmission Electron ◽  
Elongation To Failure ◽  
Shrinkage Force ◽  
Very Low Temperature

The mechanical properties and microstructures of different state cryogenic treatment 3102 Al-foil, such as H19，H26 or O state, were studied by tensile testing, optical metalloscopy (OM) and transmission electron microscope(TEM). The results showed that, after deep cryogenic treatment, the strength of H19 state increased and the elongation to failure decreased. In the same time, the yield strength increased and breaking strength decreases and the elongation decreased dramatically for O state, but, for H26 state, the strength and elongation increased dramatically, which correspond to the properties of this state at low temperatures. OM and TEM observation showed cryogenic treatment caused by the fibrous grains broken down and many grains with the size of 0.1~3μm These fine equiaxial grains can improve the strength and elongation of the Al-foil. On the contrary, the atomic shrinkage force slips high density dislocations into interface of the grains and forms terraces and fissure in it. That leads to the elongation decrease and the interface been broaden at very low temperature. The grain size of O state with cryogenic treatment is larger than without cryogenic treatment. As a result, the synthetic mechanical properties of H26 state improved by the way of cryogenic treatment, but the H19 state and O state should avoid use and put at low temperatures.

Mechanical Behavior of Quasicrystals

MRS Bulletin ◽  
1997 ◽  
Vol 22 (11) ◽  
pp. 65-68 ◽  
Author(s):  
Knut Urban ◽  
Michael Feuerbacher ◽  
Markus Wollgarten
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Mechanical Behavior ◽  
Melting Temperature ◽  
Sliding Friction ◽  
Great Promise ◽  
Brittle To Ductile Transition ◽  
Physical Reasons

Scientists have studied the mechanical properties of quasicrystalline materials for quite some time. However the difficulty in obtaining material of reasonable quality hampered systematic investigations. The progress in materials preparation in recent years has triggered new activity in this field. Furthermore the new ternary and multicomponent alloys have demonstrated great promise for use as coatings with good wear resistance and low coefficients of sliding friction. However the physical reasons for these properties and their correlation with the particular structure of quasicrystals are still not understood. As in conventional alloys, experiments under well-defined conditions are required that can serve as a basis for understanding the intrinsic mechanical properties of quasicrystals. Such studies are now increasingly possible after the development of techniques to grow larger single quasicrystals up to a few centimeters in size directly from the melt.Since the mechanical behavior of quasicrystalline alloys is to a great extent determined by a brittle-to-ductile transition at about 70% of the absolute melting temperature, it is useful to discuss the mechanical properties with reference to appropriately defined low-temperature and high-temperature regions.

Mechanical Properties and Microstructure of Certain Niaico(Hf) Alloys

1990 ◽  
Vol 186 ◽  
Author(s):  
S. M. Russell ◽  
C. C Law ◽  
L. S. Lin ◽  
G. W. Levan
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Low Temperatures ◽  
Creep Resistance ◽  
Room Temperature ◽  
Hexagonal Structure ◽  
High Temperature Strength ◽  
Room Temperature Ductility ◽  
Poor Creep Resistance

AbstractCobalt-modified NiAl alloys are being studied for their potential for room temperature ductility and toughness. An alloy of Ni - 29.3 a/o Al - 36.7 a/o Co has shown improved toughness and ductility with respect to binary NiAl alloys due in part to a stress-induced martensitic transformation. Furthermore, the cobalt additions have altered the slip behavior to {110}<111> type from {110} <001> for binary NiAl alloys. Hafnium was added to improve the alloy's relatively poor creep resistance and high temperature strength. Hf was found to be insoluble in the NiAlCo alloy and formed precipitates with a hexagonal structure. The Hfmodified alloy had improved high temperature strength. In addition, the Hf apparently changed the creep mechanism resulting in poorer creep resistance at low temperatures, but improved creep resistance at higher stresses and temperatures.

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