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Journal of Iron and Steel Research International 2021年第7期28卷 862-873页

作者： Ming-jun Zhong Ke-lu Wang shi-qiang lu Xin Li Xuan Zhou Rui Feng School of Aeronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063JiangxiChina

The isothermal compression test for Ti-6Al-7Nb alloy was conducted by using Gleeble-3800 thermal *** hot deformation behavior of Ti-6Al-7Nb alloy was investigated in the deformation temperature ranges of 940-1030℃and the strain rate ranges of 0.001-10 s^(-1).Meanwhile,the activation energy of thermal deformation was *** results show that the flow stress of Ti-6Al-7Nb alloy increases with increasing the strain rate and decreasing the deformation *** activation energy of thermal deformation for Ti-6Al-7Nb alloy is much greater than that for self-diffusion ofα-Ti andβ-*** the influence of strain on flow stress,the strain-compensated Arrhenius constitutive model of Ti-6Al-7Nb alloy was *** error analysis shows that the model has higher accuracy,and the correlation coefficient r and average absolute relative error are 0.9879 and 4.11%,*** processing map(PM)of Ti-6Al-7Nb alloy was constructed by the dynamic materials model and Prasad instability *** to PM and microstructural observation,it is found that the main form of instability zone is local flow,and the deformation mechanisms of the stable zone are mainly superplasticity and dynamic *** optimal processing parameters of Ti-6Al-7Nb alloy are determined as follows:960-995℃/0.01-0.18 s^(-1)and 1000-1030℃/0.001-0.01 s^(-1).

关键词： Ti-6Al-7Nb alloy Hot deformation behavior Strain-compensated Arrhenius constitutive model Processing map Process parameters optimization

Deformation Behavior of Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd Alloy in β/Quasi-β Forging Process

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Journal of Iron and Steel Research International 2016年第12期23卷 1297-1302页

作者： Ke-lu WANG shi-qiang lu Xian-juan DONG Xin LI De-lai OUYANG School of Aeronautical Manufacturing Engineering Nanchang Hangkong University

The hot deformation behavior of Ti 5.6Al-4.8Sn-2.0Zr-1.0Mo 0.35Si 0.85Nd alloy in β/quasi-β forging process was studied using isothermal compression tests over temperature range from 1040℃ to 1 100 ℃ and strain rates form 0. 001 s-1 to 70 s -1. The results show that the flow stress and mierostrueture are sensitive to thermomechanical parameters. The processing maps based on the dynamic materials model at strain of 0.3 and 0.7 were established. The optimum deformation thermomechanical parameters at a strain of 0.7 have two regions that exhibit the peak of power dissipation efficiency. One is the region of 1062-1100 ℃ and 10- 3 10-1.5 s -1 ; and another which represents dynamic recrystallization is 1040-1045 ℃ and 10-1.8 10- 0.5 s -1. The instable region is located where the strain rate is larger than 1 s 1 which corresponds to the mechanical instability.

关键词： titanium alloy β/quasi-β forging deformation behavior processing map process parametersoptim ization

Grain growth behavior of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy during isothermal β heat treatments

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Rare Metals 2019年第3期38卷 233-237页

作者： De-Lai Ouyang Hai-Ming Du Xia Cui shi-qiang lu Xian-Juan Dong School of Materials Science and Engineering Nanchang Hangkong University Department of Environmental Art Design Jiangxi Normal University School of Aeronautical Manufacturing Engineering Nanchang Hangkong University

Isothermal β heat treatments of Ti-6.5 Al-3.5 Mo-1.5 Zr-0.3 Si alloy were performed at the temperature of1040-1240 ℃ to examine the influence of heating conditions on grain growth of the alloy. The results show that the grain size increases with heating temperature and holding time increasing. Rapid β grain growth of the alloy takes place at the temperature of over 1140 ℃. The grain growth kinetics for the alloy follows the classical isothermal grain growth *** growth time exponent(n) of 0.5651 and activation energy(Q) of 129.6 kJ mol-1 are determined. Finally, in order to determine the grain size under different heating conditions,the grain growth model of the alloy was established.

关键词： Isothermal heating Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy Grain growth Model

Mechanical and tribological behaviors of graphene/Inconel 718 composites

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Transactions of Nonferrous Metals Society of China 2018年第10期28卷 1958-1969页

作者： Wei-han XIAO shi-qiang lu Ya-chao WANG Jing shi School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China School of Aeronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063China Department of Mechanical and Materials Engineering University of CincinnatiCincinnatiOH 45221USA

Graphene/Inconel 718 composites were innovatively synthesized through selective laser melting,and the mechanical and tribological performances of the grapheme-reinforced Inconel 718 matrix composites were *** composite microstructures were characterized by XRD,SEM and Raman *** results show that selective laser melting is a viable method to fabricate Inconel 718 matrix composite and the addition of graphene nanoplatelets leads to a significant strengthening of Inconel 718 alloy,as well as the improvement of tribological *** yield strength and ultimate tensile strength of 1.0%graphene/Inconel 718 composites(mass fraction)are 42%and 53%higher than those of pure material,and the friction coefficient and wear rate are 22.4%and 66.8%lower than those of pure *** decrease of fraction coefficient and wear rate is attributed to the improved hardness of composites and the formation of graphene nanoplatelet protective layer on the worn surfaces.

关键词： graphene graphene/Inconel 718 composite mechanical properties friction and wear properties microstructure selective laser melting

Water quality model with multiform of N/P transport and transformation in the Yangtze River Estuary

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Journal of Hydrodynamics 2016年第3期28卷 423-430页

作者：王彪卢士强林卫青杨漪帆王道增 Shanghai Academy of Environmental Sciences Shanghai 200233 China Institute of Applied Mathematics and Mechanics and Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University Shanghai 200072 China

As the Yangtze River Estuary and adjacent sea have been classified as a problem area with regard to eutrophication, it is important to explore the spatial and temporal variations of nitrogen and phosphorus （N/P） nutrients in this area. Based on danish hydraulic institute （DHI）＇s open platform Ecolab, a hydrodynamic and water quality model was developed for the Yangtze River Estuary, in which the transport and transformation processes of different forms of N/P nutrients were considered. Validations against measured data show that the model is overall reliable. Preliminary application of the model suggests that the model can simulate the characteristics of high phosphorus concentration area in the Yangtze River Estuary, and the high concentration area is closely related to the resuspension process of particulate phosphorus.

关键词： water quality model Yangtze River Estuary N/P transport and transformation

Effect of geometrical parameters on forming quality of high-strength TA18 titanium alloy tube in numerical control bending

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Transactions of Nonferrous Metals Society of China 2018年第2期28卷 309-318页

作者：方军梁闯鲁世强王克鲁江西科技师范大学江西省材料表面工程重点实验室南昌330038 南昌航空大学轻合金加工科学与技术国防重点学科实验室南昌330063

The forming quality of high-strength TA18 titanium alloy tube during numerical control bending in changing bending angle β, relative bending radius R/D and tube sizes such as diameter D and wall thickness t was clarified by finite element simulation. The results show that the distribution of wall thickness change ratio Δt and cross section deformation ratio ΔD are very similar under different β; the Δt and ΔD decrease with the increase of R/D, and to obtain the qualified bent tube, the R/D must be greater than 2.0; the wall thinning ratio Δto slightly increases with larger D and t, while the wall thickening ratio Δti and ΔD increase with the larger D and smaller t; the Δto and ΔD firstly decrease and then increase, while the Δti increases, for the same D/t with the increase of D and t.

关键词： high-strength TA18 tube geometrical parameters forming quality finite element simulation numerical control bending

Experiment and modeling of TiB_(2)/TiB boride layer of Ti−6Al−2Zr−1Mo−1V alloy

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Transactions of Nonferrous Metals Society of China 2021年第12期31卷 3752-3761页

作者： De-lai OUYANG Sheng-wei HU Cheng TAO Xia CUI Zhi-shou ZHU shi-qiang lu Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province Nanchang Hangkong UniversityNanchang 330063China Beijing Institute of Aeronautical Materials Beijing 100095China

The influence of the boriding conditions on the boride layers was examined by boriding Ti−6Al−2Zr−1Mo−1V alloy in the temperature range of 920−1120℃.The experimental results show that the boride layers were composed of a continuous thin outer layer of TiB_(2) and a thick inner layer of TiB with whiskers or needle-like morphologies that extended into the *** and compact boride layers were obtained when the boriding temperatures were 1000−1080℃,and the treatment time exceeded 8 *** boride layer depth increased with the boriding temperature and time,and the growth kinetics of the boride layers was characterized by a parabolic *** growth kinetics of the boride layers,including both TiB_(2) and TiB layers,were predicted by establishing a diffusion model,which presented satisfactory consistency with the experimental *** a result,the activation energies of boron in the TiB_(2) and TiB layers were estimated to be 223.1 and 246.9 kJ/mol,respectively.

关键词： Ti−6Al−2Zr−1Mo−1V alloy boriding microstructure modeling

A method for prediction of unstable deformation in hot forging process by simulation

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Transactions of Nonferrous Metals Society of China 2013年第12期23卷 3739-3747页

作者：鲁世强李鑫王克鲁刘诗彪傅铭旺南昌航空大学材料科学与工程学院南昌330063 南昌航空大学航空制造工程学院南昌330063 香港理工大学机械工程系

A method is proposed for prediction of the unstable deformation in hot forging process using both the determined thermomechnical parameter windows of the unstable deformation zones and finite element simulation. Taking Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy as the testing material, the thermomechnical parameter windows of the unstable deformation zones for the Ti-alloy are integrated into a commercial finite element simulation software platform. The distribution and variation of the unstable deformation zones of the alloy in hot compression process are simulated and predicted using the tailor-made finite element codes in the finite element platform. The simulation results tally with the physical experiments and the proposed method for simulation and prediction of the unstable deformation is thus verified and its efficiency is validated.

关键词： instability map unstable deformation instability deformation simulation Ti-6.5Al-3.5Mo-1.5Zr-0.3Si titanium alloy

Dynamic recrystallization behavior of burn resistant titanium alloy Ti-25V-15Cr-0.2Si

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Transactions of Nonferrous Metals Society of China 2016年第4期26卷 1003-1010页

作者：鲁世强欧阳德来崔霞王克鲁南昌航空大学航空制造与工程学院南昌330063 南昌航空大学材料科学与工程学院南昌330063

Dynamic recrystallization (DRX) behavior in β phase region for the burn resistant titanium alloy Ti?25V?15Cr?0.2Si was investigated with a compression test in the temperature range of 950?1100 °C and the strain rate of 0.001?1 s?1. The results show that deformation mechanism of this alloy in hot deformation is dominated by DRX, and new grains of DRX are evolved by bulging nucleation mechanism as a predominant mechanism. DRX occurs more easily with the decrease of strain rate and the increase of deformation temperature. Grain refinement is achieved due to DRX during the hot deformation at strain rate range of 0.01?0.1 s?1 and temperature range of 950?1050 °C. DRX grain coarsening is observed for the alloy deformed at the higher temperatures of 1100 °C and the lower strain rates of 0.001 s?1. Finally, in order to determine the recrystallized fraction and DRX grain size under different deformation conditions, the prediction models of recrystallization kinetics and recrystallized grain sizes were established.

关键词： burn resistant titanium alloy deformed microstructure deformation mechanism dynamic recrystallization prediction models

Dynamic spheroidization kinetics behavior of Ti-6.5Al-2Zr-1Mo-1V alloy with lamellar microstructure

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Transactions of Nonferrous Metals Society of China 2016年第5期26卷 1301-1309页

作者：董显娟鲁世强郑海忠南昌航空大学航空材料热加工技术航空科技重点实验室南昌330063 南昌航空大学航空制造工程学院南昌330063 南昌航空大学材料科学与工程学院南昌330063

Abstract： The dynamic spheroidization kinetics behavior of Ti-6.5Al-2Zr-1Mo-1V alloy with a lamellar initial microstructure was studied by isothermal hot compression tests in the temperature range of 750-950℃ and strain rates of 0.001-10 s^-1. The results show that the spheroidized fraction of alpha lamellae increases with the increase of temperature and the decrease of strain rate. The spheroidization kinetics curves predicted by JMAK equation agree well with experimental ones. The corresponding SEM and TEM observations indicate that the dynamic spheroidization process can be divided into two stages. The primary stage is boundary splitting formed by two competing mechanisms which are dynamic recrystallization and mechanical twin. In the second stage, the penetration of beta phase into the alpha/alpha grain boundaries is dominant, which is controlled in nature by diffusion of the chemical elements such as Al, Mo and V.

关键词： titanium alloy lamellar microstructure spheroidization kinetics equation