Zhengbing Xiao

Central South University | CSU · Light Alloy Research Institute

The hot deformation behavior and dynamic softening mechanism of 7B50 aluminum alloy were studied via isothermal compression experiments in the range of 320–460 °C/0.001–1.0 s−1. According to the flow curves obtained from the experiments, the flow behavior of this alloy was analyzed, and the Zener–Hollomon (Z) parameter equation was established. The...

In order to understand the effect of precipitation on the slip activities of Mg-Gd-Y-Zn-Zr alloys, the dislocation slip activities of solid-solution and as-aged alloys during ambient temperature quasi-in-situ compression were quantitatively investigated by electron backscattered diffraction (EBSD)-assisted slip trace analysis. First, slip trace ana...

Medium temperature compressions were implemented in the range of 433–593 K and 0.001–5 s−1 to reveal the workability and dynamic restoration mechanisms of quenched Al-6.2Zn-2.1Mg-0.15Zr alloy. The activation energy evolution with processing parameters was inspected through the modified kinetic equation that derived by integrally considering the str...

The effects of pressure on structural stability, anisotropic elasticities and electronic properties of η-MgZn2 phase were systematically investigated. The smooth variations of lattice parameters a/a0, c/c0 and formation enthalpy ΔH with increasing pressure suggest no structure transition occurred within the studied pressure range, and the decreasin...

To uncover the mechanical performance and micro-structure of Al/L12-Al3Zr interface through density functional theory, four interface models are investigated considering two different terminations of L12-Al3Zr surfaces along the [001] direction. Results indicated stacking sequence and atom type between two phases influences the mechanical performan...

To provide theoretical basis of the qualitative design for TiC particulate reinforced Mg matrix composite, the interfacial properties and fracture behavior of the Mg(11¯01)||TiC(11¯1) interfaces are systematically investigated by density functional theory. Five stable existing interfaces with different stacking sequences (FB, SA, SB, TC and TD inte...

The existing form and reaction mechanism of Sb in heat resistane Mg-Gd-Y-Sb rare earth magnesium alloy were investigated by inductive coupled plasma emission spectroscopy(ICP), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). It is found that Sb tends to form high melting point intermetallics wi...

Hot compression tests over the temperature range from 350 °C to 500 °C and strain rates range from 0.001 s−1 to 1 s−1 for homogenized Al–6.32Zn–2.10Mg alloy were carried out on a Gleeble-3800 thermal simulation machine to characterize its hot deformation behavior. At the same time, a modified Arrhenius constitutive equation was established to descr...

Through the first-principles calculations based on quantum mechanics, systematic study has been made into the segregation of solute elements (Cu/Mn/Fe/Si/Zn/Mg/Zr/V/Ti) and their effects on the Al Σ5 (210) [001] symmetrical tilt grain boundary (STGB) in 2219 alloys, which provides a theoretical basis for optimizing the distribution of solute elemen...

The structural stabilities and thermal properties of η′ and η phase at high temperature and pressure were investigated via first principles calculations combined with quasi-harmonic Debye approximation (QHA). The calculated results illustrate η′ possess high formation enthalpy with lower structural stability at high temperature, which may transits...

In this study, properties of low-index L12-Al3Nb/Al such as structure stability, thermodynamic, strength, electron properties, unstable stacking fault energy, plasticity, and fracture behavior of interface (L12-Al3Nb(001)/Al(001), L12-Al3Nb(110)/Al(110), and L12-Al3Nb(111)/Al(111)) were systematically studied. The results showed that the structure...

To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures, hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s⁻¹, respectively. Based on the modified Zerilli−Armstrong, modified Johnson-Cook, and strain-compensated Arrhenius-type models, thre...

Segregation behavior of Zr solute and its effect on the Al Σ5 (210) [100] symmetrical tilt grain boundary (GB) were investigated through first-principles calculations. Preferential sites and sequence for the replacement of Al by Zr in the GB were determined, so were the fracture energy and tensile strength of the GBs with the varied number of segre...

Deeply investigating the characteristics of the L12-Al3Sc||Al interface is a good strategy for improving the ductility and strength of next-generation Al alloys. Herein, rigid and fully relaxed models of L12-Al3Sc||Al were studied through first-principles calculations work to reveal the interface strength and fracture behavior. Results show that th...

In this paper, the properties of WO3|Y when yttrium atoms are adsorbed on the surface of WO3 are studied systematically using first-principles calculations. The most stable WO3(0 0 1) surface configuration (W-O terminal surface) was obtained by calculating the surface energy of the clean surface model. By calculating the adsorption energy (Eads), t...

Research into the co-segregation behavior of Sc and Zr solutes and their effect on the mechanical properties of the Al Σ5 (210) [110] grain boundary was carried out by the...

In order to study the effect of dynamic recrystallization on the metal flow behavior during thermal deformation, the elevated temperature compression experiments of CuCrZr alloy and 35CrMo steel are carried out using Gleeble-3810 thermal simulator. It is proved that the samples underwent obvious dynamic recrystallization behavior during thermal def...

Full investigation has been made into the Sc segregation behavior and its influence on the Al Σ5 (210) [100] symmetrical tilt grain boundary (GB) through systematic first-principles calculations. The preferential sites and sequence for the substitution of Sc for Al in the GB were determined, so were the separation energy and tensile strength of the...

In order to obtain the high-temperature flow behavior of Cu-0.5Cr-0.1Zr alloy more accurately, the hot compression test of Cu-0.5Cr-0.1Zr alloy was performed at the strain rates from 0.001 to 1.0 s⁻¹ and the deformation temperatures from 600 to 750 °C on a Gleeble-3800 thermo-simulation machine. The results show that the high-temperature flow stres...

First-principles method was performed to investigate the stabilities, electronic structures and elastic properties of L12-Al3(Sc1-xZrx) with different Zr content, and the optimized structural parameters were consistent with previous literature. The obtained negative values of both formation and mixing enthalpies suggested all the L12-Al3(Sc1-xZrx)...

The effect of homogenization on the corrosion behavior of 5083-O aluminum alloy is presented in this paper. The intergranular corrosion and exfoliation corrosion were used to characterize the discussed corrosion behavior of 5083-O aluminum alloy. The variations in the morphology, the kind and distribution of the precipitates, and the dislocation co...

To better understand the dynamic recrystallization (DRX) behavior of 35CrMo steel during hot deformation, a series of isothermal compression tests were carried out at different temperatures and strain rates. Using a constitutive equation built from the data obtained and the Arrhenius equation, the activation energy for hot deformation was determine...

The structural stability, electronic structures and elastic properties of the strengthening precipitates, namely Al3Zr, MgZn2, Al2CuMg and Al2Cu, present in 7055 aluminum alloy were investigated by the first-principles calculations based on density functional theory (DFT). The optimized structural parameters are in good agreement with literature va...

The effect of ultrasonic vibration on the microstructure, elimination of casting defects and distribution of alloyed elements at macro-scale during solidification of 35CrMo steel has been investigated. Results show that ultrasonic treatment has a significant effect on the grain refinement, especially the fragmentation of the secondary dendritic arm...

The uniaxial tensile tests of Hastelloy C-276 were performed under elevated temperature and strain rate. Considering the effects of different deformation parameters, the flow behaviour, microstructure and fracture characteristics were analysed based on the experimental data. From the rheological curves, the typical characteristics of dynamic recrys...

The effect of ultrasonic casting on microstructure and its genetic effects on strength, exfoliating corrosion, stress corrosion and electrochemical behavior of 7085 aluminum alloy have been investigated by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM), together with tensile testing, exfoliati...

In this work, a compression experiment of 35CrMo steel is carried out over a wide range of temperatures (1123-1423 K) and strain rates (0.1-10 s⁻¹) to obtain further understandings of the flow behaviors. The results show that the strain hardening effect of 35CrMo steel is stronger than that of dynamic recrystallization at low temperature and high s...

The influence of Al–Ti–B grain refiners on the microstructures of Zr-containing Al–Zn–Mg–Cu alloy was investigated by optical microscopy and scanning electron microscopy, as well as through tensile and hardness tests. A poisoning effect occurred when the grain refiner was added to the Zr-containing alloy, and the grain size increased significantly....

To better understand the effect of the components of molten 2219 Al alloy on the hydrogen content dissolved in it, the H adsorption on various positions of alloying element clusters of Cu, Mn and Al, as well as the inclusion of Al2O3, MgO and Al4C3, were investigated by means of first principles calculation, and the thermodynamic stability of H ads...

The compression deformation behaviors of 35CrMo steel at different conditions was studied by using Gleeble-3810 thermo-simulation machine under large strain. The results indicate that the flow stress curves of 35CrMo steel is affected by strain rate and deformation temperature, showing the characteristics of dynamic recovery (DRV) and dynamic recry...

The orientation relationship (OR) between Al matrix and several typical inclusions, Al2O3, MgO, AlN, TiB2, and AlB2, in Al alloy have been studied by edge-to-edge matching model and refined with Δg theory. Based on the calculation of interatomic spacing misfit and interplanar spacing misfit, the number of ORs between Al and Al2O3, MgO, AlN, TiB2, A...

Influence of temperature and strain rate on the flow behavior of electromagnetic casted low-alloyed middle carbon steel 35CrMo was investigated by means of hot compression test at temperature range of 850-1150℃ and strain rate of 0.01-10 s⁻¹ on Gleeble-3810 thermo-simulation machine. A two stage model based on flow stress-dislocation and dynamic re...

Adsorption of hydrogen on Al(111), Cu(111), Mg(0001), and Ti(0001) surfaces have been investigated by means of first principles calculation. The calculation of surface energy indicates that Mg(0001) is the most stable surface, while Ti(0001) is the most unstable surface among all the four calculated surfaces. The obtained adsorption energy shows th...

To better understand the tensile deformation and fracture behavior of 35CrMo steel during hot processing, uniaxial tensile tests at elevated temperatures and strain rates were performed. Effects of deformation condition on the flow behavior, strain rate sensitivity, microstructure transformation, and fracture characteristic were characterized and d...

The 35CrMo steel was austenitized at different heating temperature and holding time by using of orthogonal experiment method. The effects of heating temperature and holding time on average austenite grain size and the dynamic behavior of austenite grain growth in the 35CrMo steel were studied. The results show that, the austenitic grain size increa...

The effects of Ar/CCl4 combined purification on the microstructure and mechanical properties of 2219 aluminum alloy ingot were investigated by metallographic observation, SEM, mechanical properties and hydrogen content testing. The results were compared with that of the alloy refined with solid solvent (RFI), and the mechanism of refining medium on...

In this paper, the formation energies and elastic constants of α-Al2O3, MgO and AlN in both rock salt (cubic) and wurtzite (hexagonal) structures were investigated by first principles calculations. The results show that the formation energy being −17.8, −6.3, −3.06 and −3.46 eV/formula unit for α-Al2O3, MgO, AlN (rock salt) and AlN (wurtzite). It s...

The effect of homogenization on the corrosion behavior of 5083-H321 aluminum plates was studied. The intergranular corrosion, exfoliation corrosion, and electrochemical polarization, which are used to characterize the corrosion behavior of 5083-H321 aluminum alloy, were investigated. The results indicated that the samples that were not homogenized...

Hot deformation behavior of 35CrMo steel was investigated by compression tests in the temperature range of 850 to 1150 �C and strain rate range of 0.01 to 20 s21 on a Gleeble-3810 thermal simulator. According to processing maps constructed based on the experimental data and using the principle of dynamic materials modeling (DMM), when the strain is...

In order to investigate the workability and to optimize the hot forming parameters for 2026 Al alloy, hot compression tests were performed in the temperature range of 350~450°C with strain rates of 0.01~10 s −1 and 60% deformation degree on a Gleeble-1500 thermosimulation machine. The true stress-strain curves obtained exhibit that the stress incre...

In order to achieve digitization and simulation of hot forging and optimize the hot compression process parameters with 35CrMo steel, we performed experiments at temperatures from 850 to 1150 and strain rates from 0.01 to 50 s⁻¹ on a Glebe−3810 thermo-simulation machine during a series of isothermal compression tests. The results indicate that the...

The development of the recrystallization texture of the alloy AA3104 was investigated by analysis of orientation distribution functions determined by X-ray diffraction, supported by EBSD local texture analysis. A typical β-fiber with nearly 20% Bs orientation {011}<211> was detected in the final hot rolled sheet. At the beginning of annealing at 35...

To determine the influence of equilibrium phases on the 7085 alloy, the software of Thermo-Calc and JMatPro based on thermodynamic calculation was used to calculate the phases may present in the typical 7085 alloy (Al-7.8Zn-1.6Mg-1.8Cu-0.12Zr, mass fraction/%). Combined with the plane wave pseudo-potential method (PWP) and generalized gradient Appr...

By using electrochemical workstations, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and other means, the effects of two kinds of grain refiners, Al-5Ti-1B and Al-5Ti-0.2C, on microstructures and properties of 1050 aluminum presensitized plate were investigated. The results show that there are numerous coarse second-pha...

The mechanism of zirconium poisoning on the grain-refining efficiency of an Al-Ti-B based grain refiner was studied. The experiment was conducted by melting Al-5Ti-1B and Al-3Zr master alloys together. The edge-to-edge matching model was used to investigate and compare the orientation relationships between the binary intermetallic compounds present...

The poisoning mechanism of zirconium on the grain-refining efficiency of Al-Ti-C and Al-Ti-B based grain refiner was been studied by observing the phases distribution between Al 3Zr, Al 3Ti, TiC and TiB 2 particles in the Al-Ti-Zr-C and/or Al-Ti-Zr-B alloys using X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with energy di...

Microstructures and properties of 7050 aluminum alloy sheet after creep aging and artificial aging were studied by optical microscopy (OM), transmission electron microscopy (TEM), electronic tensile test and exfoliation corrosion test respectively. The results show that the loaded stress during creep aging generates continuously deformation, which...