Face-centered Cube Research Articles

A Third Generation Calphad Description of Pure Lithium.

This study, based on the analysis of existing experimental data, presents a third generation Calphad description of lithium, covering all temperature ranges, using nonlinear least squares in Matlab. We have expanded the SGTE database's description of lithium phases (face-centered cube, body-centered cube, liquid) down to 0 K with reasonable accuracy, taking into account the significant effort required to reconstruct the database for each element. During the evaluation process, it was determined that the low-temperature phase of lithium is fcc. The heat capacity of crystalline Li was accurately described using the extended Debye model. The third generation Calphad description of lithium utilized the two-state model and the extended Einstein model, leading to improved agreement with experimental data compared to previous assessments.

Study on the metallurgical mechanisms of inclusions in the FGH4096 alloy during electron beam smelting

In this study, the metallurgical mechanisms of inclusions during electron beam smelting (EBS) of a FGH4096 powder superalloy was investigated. The macroscopic morphology of the ingots, as well as the composition and structure of inclusions were studied. The effect of electron beam smelting parameters on the cooling rate, O/N content, number density and size of inclusions have been revealed. Besides, the mechanisms for inclusions removal and formation were elucidated. The results show that inclusions in the final solidification zone are mainly oxides (simple tetragonal CrO2, hexagonal Al2O3, and face-centered cube TiN), whereas the complex inclusions and carbon nitrides with Al2O3 and TiN as the nucleation cores are mainly present in the matrix. With the increase in smelting power and time, both the cooling rate and O/N content decsrease, and the smelting power shows a greater impact on the cooling rate. The number density of total inclusions increases with the increase in the smelting power. As the smelting time increases, the number density of total inclusions decreases, while the size of complex inclusions and carbon nitrides increases. This is attributed to the combined effect of cooling rate and O/N concentration in the alloy under different smelting parameters. Thermodynamic calculations indicate that Al2O3 forms in the solid-liquid phase region. The precipitation of TiN occurs when the alloy solidifies, and its precipitation temperature is higher than that of TiC. The lattice mismatch between Al2O3 and TiN is 8.14%, while that between TiC and TiN is 6.94%, which effectively promotes the heterogeneous nucleation of complex inclusions and carbon nitrides. The formation mechanisms of complex inclusions and carbon nitrides provide a theoretical basis for purification of superalloys by electron beam metallurgy.

Structural, dielectric and magnetic properties of terbium doped strontium spinel ferrite (SrFe2O4) synthesized by sol-gel method

In this research work, sol-gel technique was employed to prepare the strontium based spinel ferrite nanoparticles (SrFe2O4) with different ratios of terbium (Tb). Different characterization techniques were used to investigate the structural, morphological, dielectric and magnetic properties of the prepared samples. X-ray diffraction (XRD) result suggests that face-centered cube spinel nanocrystalline structure is formed. Crystallite size of the SrFe2O4 decreases with rising of Tb ratio. The morphology, shape and size of the SrFe2O4 were examined by scanning electron microscopy (SEM) analysis and results reveal inhomogeneous distributions of the nanostructures with high agglomeration. The electrical resistivity of the SrFe2O4 increases with rising of Tb ratio, which is confirmed from the cyclic voltammetry. It is observed that dielectric constant of all the samples decreases with increasing the frequency range. It is determined that the dielectric constants of the spinel ferrites are frequency dependent and decrease with increasing the frequency of applied electric field. The magnetic behavior of SrFe2O4 with different ratios of Tb was studied and it is found that the saturation magnetization values of samples decrease with increase in the substitution of Tb3+ at octahedral sites for Fe3+. This decrease in the values of Ms is also attributed to spin at surface of nanoparticles.

3D CFD-DEM study on fine particle migration in packed proppant layers

Fine particle migration is a crucial issue in hydraulic fracturing-based production from unconventional reservoirs and can significantly affect the effective conductivity of the packed proppant layers. In this study, to investigate the conveying behavior of fine particles, a Eulerian-Lagrangian method, namely the computational fluid dynamics–discrete element method (CFD-DEM), is adopted for 3D simulations. Two types of particles are involved in this process: larger proppant particles and fine particles. Proppant particles form a background skeleton, and a two-phase flow of fine particles and fluid is constrained in the connected pore networks. We adopt a unified CFD-DEM framework to resolve the non-slip boundary condition on the proppant particle surface and track fine particles using a four-way coupling strategy. In particular, a forcing term based on the fictitious domain method is embedded in a regular volume-averaged Navier-Stokes equation to solve the fluid motion. A perfectly packed skeleton of a face-centered cube is designed for subsequent numerical studies. The results show that the fluid and particle flow velocities are higher near the fracture surfaces than inside the interlayers. In addition, it is found that as the fine particle concentration increases, the average horizontal velocity increases, whereas the settling velocity tends to decrease.

Experimental and simulation study of microstructure and magnetic properties of (AlFeMnNi)1−x Nd x

ABSTRACT The high-entropy alloy (Al25Fe30Mn25Ni20)1−x Nd x (all in at.%) (AlFeMnNi)1−x Nd x ) was prepared by vacuum arc melting (AM) and casting method (CM). X-Ray Diffraction (XRD) and Scanning Electron Microscopy, transmission electron microscope and Integrated Energy-Dispersive X-ray spectroscopy were used to study the structure of our system. The (Al25Fe30Mn25Ni20)1−x Nd x crystallises in a Face-centred cube and centred cubic (BCC), depending on the x (x = 0.00, x = 0.01 at.% Nd). The increase of Neodymium (0.01 at.% Nd) content results in the formation of BCC structure. The chemical composition analysis of FCC and BCC crystal structures, their lattice constants demonstrate that the formation of a single BCC solid solution between 760°C and 1480°C. The Korringa–Kohn–Rostoker Method and Green's function combined with coherent potential approximation were used to study the magnetoelectronic properties of (Al25Fe30Mn25Ni20)1−x Nd x . We have obtained the value optimised of lattice parameter 2.9 Å and it is near to that obtained by experimental value using High Score programme and results XRD experimental.

Ni-Cr Alloys Assessment for Dental Implants Suitability

The performance of the field and the condition of success in oral implantology today require the review and reevaluation of the means that contribute essentially to ensuring the stability and durability of the implant, starting from the nature of the biomaterial and continuing with the characteristics of the optimally designed biosurface. This paper proposes a comparative analysis of three commercial alloys, VeraBond, Kera N, and VeraSoft, compared to a modified dental alloy, with the aim of improving some mechanical properties. They have been studied structurally and mechanically. The microstructural structure shows that the alloys crystallize in the face-centered cube system, and the cast alloy has a dendritic structure with large grains. XRD diffractograms highlight that alloys exhibit three compounds Cr156.00 Al596.00: 9013031, Ni4.00, and Cr30.00Al48.00. The hardness measurements showed values between 203 HV and 430 HV. As the percentage of silicon increases, the hardness decreases. The modulus of elasticity obtained by the indentation method for the dental alloys was in the range of 46–153 GPa. The results showed that the hardness and elastic modulus of the new alloy was significantly minimized compared to the classical alloys used.

Dopamine/DOPAC-assisted immobilization of bone morphogenetic protein-2 loaded Heparin/PEI nanogels onto three-dimentional printed calcium phosphate ceramics for enhanced osteoinductivity and osteogenicity.

Nowadays, the three-dimensional (3D) printed calcium phosphate (CaP) ceramics have well-designed geometric structure, but suffer from relative weak osteoinductivity. Surface modification by incorporating bone morphogenetic protein-2 (BMP2) onto scaffolds is considered as an efficient approach to improve their bioactivity. However, high dose and uncontrolled burst release of BMP2 may cause undesired side effect. In the present study, porous BCP ceramics with inverse face-centred cube structure prepared by digital light processing (DLP)-based 3D printing technique were used as the substrates. BMP2 proteins were loaded in the self-assembled Heparin/PEI nanogels (NP/BMP2), and then immobilized onto BCP substrates through the intermediate mussel-derived bioactive dopamine and dihydroxyphenylacetic acid (DA/DOPAC) coating layers to construct functional BCP/layer/NP/BMP2 scaffolds. Our results showed that Heparin/PEI nanogel was a potent delivery system for BMP2, and BCP/layer/NP/BMP2 scaffolds exhibited the high loading capacity, controlled release rate, and sustained local delivery of BMP2. In vitro cell experiments with bone marrow stromal cells (BMSCs) found that BCP/layer/NP/BMP2 could promote cell proliferation, facilitate cell spreading, accelerate cell migration, up-regulate expression of osteogenic genes, and improve synthesis of osteoblast-related proteins. Moreover, the murine intramuscular implantation model suggested that BCP/layer/NP/BMP2 had a superior osteoinductive capacity, and the rat femoral condyle defect repair model showed that BCP/layer/NP/BMP2 could enhance in situ bone repair and regeneration. These findings demonstrate that the incorporation of BMP2 loaded Heparin/PEI nanogels to 3D printed scaffolds holds great promise in fabricating bone graft with a superior biological performance for orthopedic application.

Mixing assisted oxidative desulfurization using a synthesized catalyst of the activated carbon supported phosphotungstic acid: A process optimization study

Desulfurization technology is vital in the removal of sulfur compounds in diesel to attain clean fuels. In this research, the mixing assisted oxidative desulfurization (MAOD) in conjunction with a high shear mixer was used with the catalyst of the activated carbon supported phosphotungstic acid. This study discusses the desulfurization of a simulated diesel, containing 2.3 wt% S of dibenzothiophene and benzothiophene in real fuel oil. The influences of mixing speed (8,000 rpm to 16,800 rpm), mixing time (30 min to 90 min), and mixing temperature (25°C to 65°C) were examined for the sulfur oxidation. A 2k full factorial design and a face-centered cube design were utilized for the screening and optimization studies, respectively, in the experimental runs. The analysis of variance was able to determine and generate a simplified quadratic model to predict the response in the MAOD process. The optimum variables for sulfur conversion were achieved at 88.5 min (mixing time), 16,800 rpm (mixing speed), and 63.28°C (mixing temperature). The confirmatory run resulted in percent oxidation of 62.37 % and validated the generated model. Moreover, the fundamental properties of diesel oil were analyzed for comparison prior to and after the MAOD method. The results revealed the retention of essential properties of the simulated diesel oil even after the MAOD treatment step. Thus, the MAOD process has successfully preserved the properties of diesel oil even after its treatment process. This indicates a promising result of the MAOD process favorable for its future applications.

Study on the Electromagnetic Scattering Characteristics of High-Speed Target With Non-Uniform Plasma via the FCC-FDTD Method

The face-centered cube (FCC) grid has more sampling points than the traditional Yee cell (as it contains a total of 14 grid points, of which six are center points and eight are vertices, and each grid point has three field components). Thus, FCC is better than the former in dealing with the dispersion error of anisotropic media. On the basis of this feature, this article first derived the FCC-finite-difference time-domain (FDTD) iterative formula for nonuniform plasma on the basis of FCC grid and verifies the accuracy of the algorithm. This algorithm is combined with the nonuniform plasma flow field model of hypersonic vehicles, and the backward single-station radar cross sections (RCSs) of vertical polarization (VV) and horizontal polarization (HH) are calculated under different flight altitudes, flight velocities, and external conditions. Results showed that as flying height increased or flying speed decreased, it results in an increase in RCS. Different external magnetic fields and incident angles also had an obvious impact on the electromagnetic scattering characteristics. From the perspective of electromagnetic wave polarization, both VV polarization and HH polarization have a great impact on RCS. These results provide a theoretical basis for studying the electromagnetic scattering characteristics of nonuniform plasma targets.

Electrochemical behavior and electrodeposition of Fe-Co-Ni thin films in choline chloride/urea deep eutectic solvent

Fe-Co-Ni coating, a vital type of transition metal alloy, shows great potential in the field of hydrogen storage and magnetic materials. In this study, Fe-Co-Ni coatings were prepared on Cu substrates from a deep eutectic solution of choline chloride/2Urea (ChCl/2Urea) DES by electrodeposition. The effects of deposition potential on the morphology, chemical composition, crystal structure, corrosion resistance and magnetic properties of nanostructured Fe-Co-Ni coatings were investigated. The results revealed that the reduction process of Fe-Co-Ni alloy on the Cu electrode in ChCl/2Urea DES was irreversible three-dimensional instantaneous nucleation, which was controlled by diffusion. The surface morphology, microstructure, compose and crystallite size of the Fe-Ni-Co alloy were related to the deposition potential. The Fe content of the electrodeposited alloys showed a maximum of 48.17 at% at the applied potential of −1.3 V and a positive correlation was observed between the Fe content and electrodeposition potential in the investigated potential range. The nickel-rich coatings were obtained at high potential and iron-rich coatings were obtained at low potential. The less roughness, more compact grain and uniform flat Fe-Co-Ni coatings were prepared under a more negative potential. The Fe-Co-Ni coatings were composed of face-centered cube (fcc, NiFe) and body-centered cube crystals (bcc, FeCo). With the negative shift of deposition potential, the structure of Fe-Co-Ni coatings grew preferentially toward FeCo(110) and FeCo(211) crystal surfaces. The Fe-Co-Ni coatings prepared from ChCl/2Urea DES at different deposition potentials showed good corrosion resistance. Fe-Co-Ni coating that is produced at the deposition potential of −1.2 V, exhibited a more positive corrosion potential and obvious magnetic anisotropy.

Bulky Thiolate-Protected Silver Nanocluster Ag 213 (Adm-S) 44 Cl 33 with Excellent Electrocatalytic Performance toward Oxygen Reduction

Bulky Thiolate-Protected Silver Nanocluster Ag ₂₁₃ (Adm-S) ₄₄ Cl ₃₃ with Excellent Electrocatalytic Performance toward Oxygen Reduction

Fabrication and biological evaluation of 3D-printed calcium phosphate ceramic scaffolds with distinct macroporous geometries through digital light processing technology.

Digital light processing (DLP)-based 3D printing technique holds promise in fabricating scaffolds with high precision. Here raw calcium phosphate (CaP) powders were modified by 5.5% monoalcohol ethoxylate phosphate (MAEP) to ensure high solid loading and low viscosity. The rheological tests found that photocurable slurries composed of 50 wt% modified CaP powders and 2 wt% toners were suitable for DLP printing. Based on geometric models designed by computer-aided design (CAD) system, three printed CaP ceramics with distinct macroporous structures were prepared, including simple cube, octet-truss and inverse face-centered cube (fcc), which presented the similar phase composition and microstructure, but the different macropore geometries. Inverse fcc group showed the highest porosity and compressive strength. The in vitro and in vivo biological evaluations were performed to compare the bioactivity of three printed CaP ceramics, and the traditional foamed ceramic was used as control. It suggested that all CaP ceramics exhibited good biocompatibility, as evidence by an even bone-like apatite layer formation on the surface, and the good cell proliferation and spreading. A mouse intramuscular implantation model found that all of CaP ceramics could induce ectopic bone formation, and foam group had the strongest osteoinduction, followed by inverse fcc, while cube and octet-truss had the weakest one. It indicated that macropore geometry was of great importance to affect the osteoinductivity of scaffolds, and spherical, concave macropores facilitated osteogenesis. These findings provide a strategy to design and fabricate high-performance orthopedic grafts with proper pore geometry and desired biological performance via DLP-based 3D printing technique.

Multifaceted phytogenic silver nanoparticles by an insectivorous plant Drosera spatulata Labill var. bakoensis and its potential therapeutic applications

The current investigation highlights the green synthesis of silver nanoparticles (AgNPs) by the insectivorous plant Drosera spatulata Labill var. bakoensis, which is the first of its kind. The biosynthesized nanoparticles revealed a UV visible surface plasmon resonance (SPR) band at 427 nm. The natural phytoconstituents which reduce the monovalent silver were identified by FTIR. The particle size of the Ds-AgNPs was detected by the Nanoparticle size analyzer confirms that the average size of nanoparticles was around 23 ± 2 nm. Ds-AgNPs exhibit high stability because of its high negative zeta potential (− 34.1 mV). AFM studies also revealed that the Ds-AgNPs were spherical in shape and average size ranges from 10 to 20 ± 5 nm. TEM analysis also revealed that the average size of Ds-AgNPs was also around 21 ± 4 nm and the shape is roughly spherical and well dispersed. The crystal nature of Ds-AgNPs was detected as a face-centered cube by the XRD analysis. Furthermore, studies on antibacterial and antifungal activities manifested outstanding antimicrobial activities of Ds-AgNPs compared with standard antibiotic Amoxyclav. In addition, demonstration of superior free radical scavenging efficacy coupled with potential in vitro cytotoxic significance on Human colon cancer cell lines (HT-29) suggests that the Ds-AgNPs attain excellent multifunctional therapeutic applications.

An innovation in finite element simulation via crystal plasticity assessment of grain morphology effect on sheet metal formability

Experimental and numerical study regarding the uniaxial tensile test and the forming limit diagram are addressed in this paper for AL2024 with the face-centered cube structure. First, representation of a grain structure can be obtained directly by mapping metallographic observations via scanning electron microscopy approach. Artificial grain microstructures produced by Voronoi Tessellation method are employed in the model using VGRAIN software. By resorting to the finite element software (ABAQUS) capabilities, the constitutive equations of the crystal plasticity were utilized and implemented as a user subroutine material UMAT code. The hardening parameters were calibrated by a trial and error approach in order to fit experimental tensile results with the simulation. Then the effect of the changing grain size, the heterogeneity factor, and the grain aspect ratio were studied for a uniaxial tensile test to emphasize the importance of the microstudy behavior of grains in material behavior. Furthermore, the polycrystal plasticity grain distribution was employed in the Nakazima test in order to obtain the forming limit diagram. The crystal plasticity-driven forming limit diagram reveals more accurate strains, taking into account the involving the micromechanical features of the grains. An innovative approach is pursued in this study to discover the necking angle, both in tensile test or Nakazima samples, showing a good agreement with the experiment results.

Preparation and characterization of submicron-cerium oxide by hypergravity coprecipitation method

Submicron-cerium oxide particles were synthesized by applying hypergravity using ammonium bicarbonate (precipitant) and cerium nitrate hexahydrate (precursor). The influence of the concentration, pH, dispersant loading, flow rate, rotation speed of the hypergravity rotating bed, calcination temperature, and time on the cerium oxide particle size were examined by zeta potential, solid–liquid contact angle, thermo-gravimetry–differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The cerium oxide particles were highly dispersed, with an average particle size of 200 nm. Calcining at 650 °C for 1.5 h afforded the smallest particles. The crystallite size and fraction crystallinity increased with prolonged calcination. Crystalline cerium dioxide grew along three crystal planes, forming a complete face-centered cube, affording high hardness and activity of the polishing powder. The optimal conditions were: cerium nitrate concentration: 0.7 mol/L, cerium nitrate/ammonium bicarbonate molar ratio: 1:3, dispersant mass fraction: 3%, cerium nitrate initial pH: 4–5; the precursor solution was adjusted to pH 9 with ammonia water. Hypergravity coprecipitation with 1.5 h calcination afforded submicron-sized cerium oxide with a uniform size distribution using ammonium bicarbonate in an industrially viable process. The simple and low-cost manufacturing process may enable the development of hypergravity-assisted chemical synthesis technology.

CrIII8NiII6]n+ Heterometallic Coordination Cubes.

Three new heterometallic [CrIII8NiII6] coordination cubes of formulae [CrIII8NiII6L24(H2O)12](NO3)12 (1), [CrIII8NiII6L24(MeCN)7(H2O)5](ClO4)12 (2), and [CrIII8NiII6L24Cl12] (3) (where HL = 1-(4-pyridyl)butane-1,3-dione), were synthesised using the paramagnetic metalloligand [CrIIIL3] and the corresponding NiII salt. The magnetic skeleton of each capsule describes a face-centred cube in which the eight CrIII and six NiII ions occupy the eight vertices and six faces of the structure, respectively. Direct current magnetic susceptibility measurements on (1) reveal weak ferromagnetic interactions between the CrIII and NiII ions, with JCr-Ni = + 0.045 cm−1. EPR spectra are consistent with weak exchange, being dominated by the zero-field splitting of the CrIII ions. Excluding wheel-like structures, examples of large heterometallic clusters containing both CrIII and NiII ions are rather rare, and we demonstrate that the use of metalloligands with predictable bonding modes allows for a modular approach to building families of related polymetallic complexes. Compounds (1)–(3) join the previously published, structurally related family of [MIII8MII6] cubes, where MIII = Cr, Fe and MII = Cu, Co, Mn, Pd.

OFAT versus DOE as two optimization protocols for the chromatographic analysis of some OTC pharmaceuticals carrying negative cardiovascular effects and administered by pregnant and breast-feeding females: Application to dose dependent effect

AbstractA simple HPLC technique has been utilized for rapid and sensitive quantitative analysis of two mixtures of drugs that are used during pregnancy and lactation. Drugs of the first mixture are used to manage gastrointestinal tract illness that are common during early stages of pregnancy, while pharmaceutical agents of the second mixture are administered over the counter as galactagogues or to overcome postpartum depression. Mixture I includes famotidine (FMT), ranitidine (RNT), nizatidine (NZT), and pantoprazole (PNT), which were separated on a C18 column using a mobile phase composed of methanol: 0.02 M sodium dihydrogen phosphate (60:40, v/v) of pH 6.9, adopting UV detection at 240 nm at a flow rate of 1 mL/min. Mixture II on the other hand, consists of domperidone (DOM), metoclopramide (MET), and sulpiride (SUL). These drugs were eluted using the same column and flow rate as those in mixture I, using a mobile phase consisting of acetonitrile: 0.075 M sodium dihydrogen phosphate (30:70, v/v) of pH 6 adopting a detection wavelength 270 nm. Two optimization protocols were utilized to optimize the chromatographic separation conditions, namely one factor at a time (OFAT) and design of experiments (DOE) where face centered cube response surface experimental design was chosen for this investigation. Comparison of the results obtained from both protocols reveals the accordance between them.Full validation procedure under guidance of United States Pharmacopoeia (USP) was applied to the proposed methods which enabled their application to separate the drugs of both mixtures in spiked rat whole blood samples and in vivo analysis of rat heart blood.

Effects of the elemental composition of high-entropy filler metals on the mechanical properties of dissimilar metal joints between stainless steel and low carbon steel

Owing to the cocktail effect in high-entropy alloys, a good combination of strength and toughness of a welded joint could be theoretically achieved, by modifying the elemental composition of the filler metals with a high-entropy design. However, few studies have concentrated on this issue so far. In the present study, multi-component mixed powders of (CrMnFe)x(CoNi)y, with five types of the content ratios of the body-centered cube (BCC) and face-centered cube (FCC) forming elements, were used as filler metals to achieve dissimilar welding between 304 stainless steel and Q235 carbon steel by laser deposition welding. By comparative analysis of the microstructures and mechanical properties of the dissimilar joints, the effects of an elemental composition factor of μ (μ=x/y) on the hardness, tensile and bending properties of the dissimilar joints were explored. It was found that the elemental composition of mixed powders had an impact on the mechanical properties of dissimilar joints. Too high or too low content of BCC/FCC forming elements in filler metals cannot promote the appropriate mechanical properties. As an increase in the content of BCC forming elements, the hardness in weld zones was significantly increased, especially for the mixed powders with a high value of μ (≥7/3). The powders of (CrMnFe)5(CoNi)5 resulted in the best comprehensive mechanical properties of the dissimilar joint.

ANALYSIS OF FASTENING METALS STRUCTURE BY CLUSTER MODEL ON THE BASIS OF RENGENODYFRACTION STUDIES DIAGNOSI

Worked computer program of design cluster structure of fusions to simple metals with a crystalline grate face - centered cube (FCC) and volume cube centred (VCC) of for comparison with experimental data of x-ray diffraction analysis.

Mechanical properties and deformation behavior of dual-phase Al0.6CoCrFeNi high-entropy alloys with heterogeneous structure at room and cryogenic temperatures

Dual-phase Al0.6CoCrFeNi high-entropy alloys (HEAs) with heterogeneous structure are obtained by cold rolling and annealing. Tensile experiments show that this alloy exhibits excellent combinations of yield strength, tensile strength and tensile elongation at room (298 K) and cryogenic (77 K) temperatures. Through the thermodynamic formula, the stacking fault energy of face-centered cube (fcc) phases in Al0.6CoCrFeNi alloys are calculated to be 49.33 mJ/m2 and 28.69 mJ/m2 at 298 K and 77 K, respectively. Combining with EBSD (electron backscattering diffraction) and TEM (transmission electron microscopy), it is concluded that the deformation of dual-phase Al0.6CoCrFeNi alloys with heterogeneous structure at 298 K is mainly dominated by the dislocation slip in fcc plus bcc (body-centered cube) phases, and the deformation mode at 77 K can be divided into two stages: (1) when the true strain is between 0 and 3.8%, the plasticity is mainly caused by dislocation slip of fcc and bcc phases; (2) when the true strain is between 3.8% and samples fracture, the plasticity is mainly induced by deformation twins in fcc phase and dislocation slip in bcc phase.