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基于响应面法的轻质尾翼均匀挤压成形数值模拟及模具结构优化

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兵工学报 2024年第6期45卷 1824-1839页

作者：贾晶晶张治民于建民薛勇吴昂中北大学机电工程学院山西太原030051 郑州轻工业大学机电工程学院河南郑州450000 中北大学材料科学与工程学院山西太原030051

针对轻质镁合金尾翼正挤压成形金属流动不均匀和力学性能各向异性大的问题,提出一种可调控金属均匀流动的金属蓄料池模具结构。基于Deform-3D有限元模拟分析,采用Box-Behnken响应曲面法以金属蓄料池结构参数:深度h、池壁距尾翼芯部型腔... 详细信息

针对轻质镁合金尾翼正挤压成形金属流动不均匀和力学性能各向异性大的问题,提出一种可调控金属均匀流动的金属蓄料池模具结构。基于Deform-3D有限元模拟分析,采用Box-Behnken响应曲面法以金属蓄料池结构参数:深度h、池壁距尾翼芯部型腔长度D 1、池壁距翼片型腔长度D 2和池壁与翼片型腔之间夹角α为变量,建立出模口金属流速均方差和成形载荷与金属蓄料池结构参数之间的响应关系。响应曲面分析结果表明:最佳的金属蓄料池结构参数为h=7 mm,D 1=13 mm,D 2=6 mm,α=11°。采用优化后的模具结构参数进行模拟验证和物理试验,金属流动不均匀和力学性能各向异性均得到改善,并成功试制出形状尺寸和力学性能指标满足要求的尾翼形零件。

关键词：尾翼构件均匀流动有限元模拟模具优化 Box-Behnken响应曲面

Effect of aging treatment on the precipitation transformation and age hardening of Mg-Gd-Y-Zn-Zr alloy

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Journal of Magnesium and Alloys 2023年第12期11卷 4628-4643页

作者： Mu Meng Honglei Zhang Zhi Gao Genxing Lei jianmin yu College of Materials Science and Engineering North University of ChinaXueyuan Road 3Taiyuan 030051China Beijing North Vehicle Group Corporation ZhuJiaFen 5th LiBeijing 100072China

In this study, the precipitation transformation and age hardening of solution-treated Mg-9Gd-4Y-2Zn-0.5Zr(wt.%) alloy were investigated at different aging treatment parameters. The precipitation sequences of the alloy aged at 200℃, 250℃ and 300℃ are β’’(DO19) → β’(BCO) → β(FCC), β’’(DO19) → β’(BCO) → β_(1)(FCC) → β(FCC) and β(FCC), respectively. The streaks sequences of the alloy aged at 200℃, 250℃ and 300℃ are SF, SF → 14H-LPSO and SF → 14H-LPSO, respectively. For the alloy aged at 200℃ and 250℃, the increase in hardness with increasing aging time is contributed from the increase in precipitate volume fraction and the transformation from β’’ to β’ phase with basal → prismatic and spherical → spindle-like precipitate changes. The decrease in hardness after the peak-aging stage is attributed to the appearance of micro-sized β precipitates. Because of the smaller size of precipitates and the triangular arrangement of β’ precipitate, the hardness of the alloy aged at 200℃ is higher than that aged at 250℃. For the alloy aged at 300℃, the appearance of only micro-sized β precipitate and its coarsening with increasing aging time leads to the lowest hardness and an overall decrease in hardness with the aging time.

关键词： Mg-Gd-Y-Zn-Zr alloy Aging treatment Precipitation transformation Age hardening

纳米多晶Mg-Y合金压缩力学行为的分子动力学研究

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精密成形工程 2024年第5期16卷 108-114页

作者：王伟光吴耀金蒋虎于建民李琳琳中北大学航空宇航学院太原030051 中北大学材料科学与工程学院太原030051 吉林工程技术师范学院长春130052

目的研究纳米多晶Mg-Y合金在不同温度和应变速率下的力学响应以及不同变形条件下的晶粒变形行为。方法通过ATOMSK软件构建了晶粒取向随机的纳米多晶Mg-Y二元合金模型,利用LAMMPS软件,在400~520 K温度及1×10^(10)s^(−1)、1×10^(9)s^(−1... 详细信息

目的研究纳米多晶Mg-Y合金在不同温度和应变速率下的力学响应以及不同变形条件下的晶粒变形行为。方法通过ATOMSK软件构建了晶粒取向随机的纳米多晶Mg-Y二元合金模型,利用LAMMPS软件,在400~520 K温度及1×10^(10)s^(−1)、1×10^(9)s^(−1)应变速率下完成了纳米多晶Mg-Y合金的压缩模拟,借助后处理OVITO软件对模拟结果进行了分析。结果随着温度的升高,纳米多晶Mg-Y合金的力学性能降低,且在温度上升到一定程度后具有一定的梯度规律。在微观层面,温度的上升使总体位错密度下降,但减少了晶粒内部的长程位错和位错扭结,并且类位错与类位错的比例上升。纳米多晶Mg-Y合金在高应变速率下的屈服强度更高,在原子排布层面上,六方最密堆积的比例降低。结论温度升高带来的更多能量使低能态的Y原子更容易参与到位错产生、消失过程中,还加剧了类型位错向类位错的转变。高应变速率通过大幅度转化基体Mg的六方最密堆积形式,增加了晶界的破碎和形核,影响了合金的力学性能。

关键词： Mg-Y合金分子动力学压缩温度应变速率

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从铂化合物制备尾液中回收超细铂粉的研究

贵金属 2024年第2期45卷 59-63,68页

作者：毕向光王文思余泽锦刘辉冯丰赵云昆余建民卿山昆明理工大学冶金与能源工程学院昆明650093 昆明贵研催化剂有限责任公司昆明650106 昆明贵金属研究所昆明650106

将不同的铂化合物制备尾液经过氯化铵沉淀,实现与其他杂质元素的分离,将铂转化为氯铂酸铵中间体,经液相化学还原得到超细铂粉。研究了中间体形态、(NH_(4))2PtCl6溶液浓度、分散剂种类及加入量对铂粉粒度、比表面积、形貌的影响。结果表... 详细信息

将不同的铂化合物制备尾液经过氯化铵沉淀,实现与其他杂质元素的分离,将铂转化为氯铂酸铵中间体,经液相化学还原得到超细铂粉。研究了中间体形态、(NH_(4))2PtCl6溶液浓度、分散剂种类及加入量对铂粉粒度、比表面积、形貌的影响。结果表明,铂化合物尾液种类不影响超细铂粉的形貌及颗粒尺寸,以PVP为分散剂,硼氢化钠为还原剂,在优化条件下制备的铂粉平均粒度约150nm,纯度99.99%,直收率97.8%,颗粒形貌均匀、分散程度高、比表面积及颗粒尺寸均符合超细铂粉国家标准,方法可用于从多种铂类化合物制备尾液直接制备超细铂粉。

关键词：铂类化合物制备尾液还原剂超细铂粉

Recent research and development on forming for large magnesium alloy components with high mechanical properties

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Journal of Magnesium and Alloys 2023年第11期11卷 4054-4081页

作者： Zhimin Zhang jianmin yu Yong Xue Beibei Dong Xi Zhao Qiang Wang College of Materials Science and Engineering North University of China3 Xueyuan RoadTaiyuan 030051China

The lightweight of high-end equipment relies on high mechanical properties magnesium(Mg) alloy structural components, because it is the best way to improve equipment service performance and reduce energy consumption. This article summarizes the current progress and characteristics of large-scale high-performance Mg alloy components by analyzing the strengthening-toughening mechanisms, characteristics of plastic forming, and the preparation of large high mechanical properties forging blanks. Due to the lack of breakthroughs in the key technologies for forming large-scale Mg alloy components, their uniformity of mechanical properties and consistency are poor, the forming accuracy of components is low, and the production cost is high, which limit their engineering application and restrict the lightweight level of high-end equipment. In view of the above problems, the forming trends and research directions of large-scale and high mechanical properties Mg alloy components are proposed in this paper. It can provide help for the breakthrough of the key technology of large-scale Mg alloy components with high mechanical properties and expand the application of Mg alloy in high-end products.

关键词： Mg alloys Wrought Mg alloys components Plastic forming Large-scale Mg alloys components High mechanical properties

Influence of strain rate on grain refinement and texture evolution under complex shear stress conditions

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镁合金学报(英文) 2023年第7期11卷 2558-2584页

作者： Zhaocan Li Guoqin Wu jianmin yu Jiebing Wang Jingjing Han Huiyong Cui Zhimin Zhang College of Materials Science and Engineering North University of China3 Xueyuan RoadTaiyuan 030051China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China

The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were *** increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also *** is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly *** DRX fractions of CS and CT samples are decreased with increased strain *** low DRX fraction at high strain rate is related to the insufficient time for grains to *** DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning *** the same time,the texture strength is enhanced as the strain rate ***,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is *** complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected *** with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain *** is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second *** the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are *** with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.

关键词： Simple shear Compression-shear Compression-torsion Grain refinement Texture evolution ASB

Grain refinement impact on the mechanical properties and wear behavior of Mg-9Gd-3Y-2Zn-0.5Zr alloy after decreasing temperature reciprocating upsetting-extrusion

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Journal of Magnesium and Alloys 2022年第12期10卷 3506-3519页

作者： Wenlong Xu jianmin yu Leichen Jia Chang Gao Zhan Miao Guoqin Wu Guojun Li Zhimin Zhang School of Material Science and Engineering North University of ChinaTaiyuan 030051China

Based on the deforming technique of severe plastic deformation(SPD), the grain refinement of a Mg-9Gd-3Y-2Zn-0.5Zr alloy treated with decreasing temperature reciprocating upsetting-extrusion(RUE) and its influence on the mechanical properties and wear behavior of the alloy were studied. The RUE process was carried out for 4 passes in total, starting at 0 ℃ and decreasing by 10 ℃ for each pass. The results showed that as the number of RUE passes increased, the grain refinement effect was obvious, and the second phase in the alloy was evenly distributed. Room temperature tensile properties of the alloy and the deepening of the RUE degree showed a positive correlation trend, which was due to the grain refinement, uniform distribution of the second phase and texture weakening. And the microhardness of the alloy showed that the microhardness of RUE is the largest in 2 passes. The change in microhardness was the result of dynamic competition between the softening effect of DRX and the work hardening effect. In addition, the wear resistance of the alloy showed a positive correlation with the degree of RUE under low load conditions. When the applied load was higher, the wear resistance of the alloy treated with RUE decreased compared to the initial state alloy. This phenomenon was mainly due to the presence of oxidative wear on the surface of the alloy, which could balance the positive contribution of severe plastic deformation to wear resistance to a certain extent.

关键词： Mg-9Gd-3Y-2Zn-0.5Zr alloy Reciprocating upsetting-extrusion Grain refinement Texture Mechanical properties Wear behavior

Decreased eggshell strength caused by impairment of uterine calcium transport coincide with higher bone minerals and quality in aged laying hens

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1258-1277页

作者： yu Fu jianmin Zhou Martine Schroyen Haijun Zhang Shugeng Wu Guanghai Qi Jing Wang Key Laboratory of Feed Biotechnology Ministry of Agriculture and Rural AffairsInstitute of Feed ResearchChinese Academy of Agricultural SciencesBeijing 100081China Precision Livestock and Nutrition Laboratory Gembloux Agro‑Bio TechTERRA Teaching and Research CentreUniversity of LiegeGembloux B‑5030Belgium

Background Deteriorations in eggshell and bone quality are major challenges in aged laying *** study compared the differences of eggshell quality,bone parameters and their correlations as well as uterine physiologi-cal characteristics and the bone remodeling processes of hens laying eggs of different eggshell breaking strength to explore the mechanism of eggshell and bone quality reduction and their interaction.A total of 24074-week-old Hy-line Brown laying hens were selected and allocated to a high(HBS,44.83±1.31 N)or low(LBS,24.43±0.57 N)eggshell breaking strength *** A decreased thickness,weight and weight ratio of eggshells were observed in the LBS,accompanied with ultrastructural deterioration and total Ca *** quality was negatively correlated with eggshell quality,marked with enhanced structures and increased components in the *** the LBS,the mammillary knobs and effective layer grew *** the initiation stage of eggshell calcification,a total of 130 differentially expressed genes(DEGs,122 upregulated and 8 downregulated)were identified in the uterus of hens in the LBS relative to those in the *** DEGs were relevant to apoptosis due to the cellular Ca *** values of p62 protein level,caspase-8 activity,Bax protein expression and lower values of Bcl protein expression and Bcl/Bax ratio were seen in the *** assay and hematoxylin-eosin staining showed a significant increase in TUNEL-positive cells and tissue damages in the uterus of the *** few DEGs were identified at the growth stage,similar uterine tissue damages were also observed in the *** expressions of runt-related transcription factor 2 and osteocal-cin were upregulated in humeri of the *** diameter and more structural damages of endocortical bones and decreased ash were observed in femurs of the *** The lower eggshell breaking strength may be attributed to a declined Ca transport due to uterine tissue damages,which

关键词： Bone parameter Calcium transport Eggshell quality Laying hen Tissue damage

Improved Scatter Search Algorithm for Multi-skilled Personnel Scheduling of Ship Block Painting

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Journal of Harbin Institute of Technology(New Series) 2024年第1期31卷 1-15页

作者： Guanglei Jiao Zuhua Jiang jianmin Niu Wenjuan yu Department of Industrial Engineering and Management Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Ship Technology Research Institute Shanghai 200032China

This paper focuses on the optimization method for multi-skilled painting personnel *** budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.

关键词： ship painting personnel scheduling multi⁃skilled workers scatter search task constraints

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