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Minor pre-tension and aging-induced fine dispersion of precipitates for strength-ductility coordination in Mg-Y-Nd alloys

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Journal of Rare Earths 2025年

作者： Yanan Yu Luyi Han Ximan Sun Xiangjian Zhu Dejin Wei Guangchun Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University Jinan 250061 China State key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan 250061 China

Increasing the number density of precipitates is a critical factor in enhancing the strength-ductility balance of metallic materials. This study investigates the precipitation behavior of dislocation-induced precipitates and its impact on the strength-ductility coordination through minor pre-tension applied before aging. Statistical analysis of precipitate size reveals that pre-tension-induced dislocations provide additional nucleation sites, resulting in β′ phase refinement and a more dispersed distribution, which effectively alleviates stress concentration. In contrast, non-pre-tensioned samples exhibit increased grain boundary precipitates and larger PFZs, leading to extensive intergranular fracture. The pre-tension treatment accelerates aging kinetics, significantly reducing prismatic dislocation density after aging. This reduction facilitates β 1 phase nucleation and its linear arrangement along specific prismatic planes. This work systematically examined intra-granular precipitation strengthening induced by minor pre-tension, along with the interaction mechanisms between grain boundary precipitates and PFZs, providing crucial insights for developing high-performance magnesium alloys.

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Interaction between crack and twins in TMS-82 superalloy during thermomechanical fatigue process

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Progress in Natural Science:materials International 2013年第5期23卷 508-513页

作者： Baidong Fu Jianxin Zhang H.Harada Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education) Shandong University National Institute for Materials Science 1-2-1 Sengen

Thermomechanical fatigue behavior of a nickel base single crystal superalloy TMS-82 has been *** was found that the micropores in the alloy tend to initiate large amounts of deformation twins and the crack causes many twins to occur during its *** is postulated that these twins around the micropores or the crack are induced by the stress eld of the micropores or the crack tip,respectively.A thermodynamic model is adopted linking the twin formation energy with the stress eld around the crack tip,which explains the observed results with good *** in uencing factors for a crack to stimulate twins around it are shown by the model,which might provide possible ways to enhance the alloy’s thermomechanical fatigue performance.

关键词： Twin Crack Formation energy Stress eld Nickel base superalloy

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Numerical analysis of weld pool geometry in pulsed current plasma arc welding

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China Welding 2010年第3期19卷 6-10页

作者：孙俊华武传松 Sun Junhua and Wu Chuansong Key Lab for Liquid-Solid Structure Evolution and Materials Processing （Ministry of Education） and Institute for Materials Joining Shandong University Jinan 250061.

Numerical analysis of weld pool shape and size is of great significance for selection and optimization of the process parameters in pulsed current plasma arc welding （PAW）. In this paper, a mathematical model and relevant algorithm are developed to determine the temperature profiles and weld pool geometry in pulsed current PAW through employing an adaptive heat source model. The volumetric heat source consists of semi-ellipsoid at upper part and a conic body at lower part along the workpiece thickness direction. The dynamic variation features of weld pool shape during a pulse cycle are numerically simulated. The calculated weld cross-section is consistent with the measure one.

关键词： pulsed current plasma arc welding weld pool numerical analysis

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liquid metal assisted regulation of macro-/micro-structures and mechanical properties of nanoporous copper

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Science China(Technological Sciences) 2021年第10期64卷 2229-2236页

作者： ZHANG Ying BAI QingGuo YANG WanFeng ZHANG ZhongHua Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China School of Applied Physics and Materials Wuyi UniversityJiangmen 529020China

Nanoporous metals have received significant attention as a new class of structural and functional ***,the macroscopic brittle fracture under the tensile test is an impediment to their practical ***,it is of central importance to develop nanoporous materials with low cost and high tensile ***,a nanoporous Cu film supported on a pure Cu substrate(NPC@Cu)was fabricated by utilizing a liquid Ga assisted alloying-dealloying strategy,and the thickness of NPC film can be precisely regulated by changing the mass loading of liquid ***-situ X-ray diffraction was performed to further explore the alloying/dealloying *** NPC@Cu films show good tensile mechanical properties with a minimum elongation of 13.5%,which can be attributed to the good interface bonding and certain modulus matching between the nanoporous Cu layer and the Cu *** findings demonstrate that the design of film-substrate structure provides a feasible strategy for enhancing the mechanical properties of nanoporous metals.

关键词： nanoporous metals dealloying mechanical properties in-situ X-ray diffraction structural regulation

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Promoting amorphization of commercial TiO_(2) upon sodiation to boost the sodium storage performance

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Journal of Energy Chemistry 2023年第6期81卷 379-388,I0009页

作者： Tao Li Ling-Yun Kong Xue Bai Yan-Xiang Wang Yong-Xin Qi Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials of Ministry of Education State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250061ShandongChina School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590ShandongChina

Anatase TiO_(2) is a promising anode material for sodium-ion batteries,yet the low electronic and ionic conductivities are the main obstacles for its practical *** though the amorphization of TiO_(2) upon sodiation has already been observed,its underneath mechanisms are not fully ***,a low-cost nitrogen-containing carbon source of polyacrylonitrile is adopted to modify commercial anatase TiO_(2) by a convenient and nontoxic ball-milling technique combined with subsequent annealing *** particular,the employment of a nitrogen-doping approach accompanied by nitrogendoped carbon coating,results in a greatly improved conductivity,overall leading to a high reversible capacity of about 260 m A h g^(-1)at 25 m A g^(-1),superior rate capabilities,and an ultra-stable capacity of about 186 m A h g^(-1)after 1600 cycles at 500 m A g^(-1).Detailed characterizations denote that the improved conductivity as well as the small size of the synthesized TiO_(2) grains play a key role in the TiO_(2) amorphization upon sodiation,with the TiO_(2)/C nanocomposite undergoing a complete amorphization in just few ***,the irreversible amorphization of TiO_(2) is confirmed to be a crucial ingredient facilitating the Na+diffusion kinetics and pseudocapacitive behavior,thus boosting the sodium storage performance.

关键词： Commercial TiO_(2) Anode material Amorphization Nitrogen doping Sodium-ion battery

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Structural optimization of Sr/Zn-phosphate conversion coatings triggered by ions preloading on micro/nanostructured titanium surfaces for bacterial infection control and enhanced osteogenesis

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Journal of Nanobiotechnology 2025年第1期23卷 1-23页

作者： Zuo, Kangqing Li, Aonan Si, Taoning Lei, Weiyi Liu, Yusheng Zhang, Linbo Zhang, Taixing Xiao, Guiyong Lu, Yupeng Li, Ningbo Department of Stomatology Shandong Provincial Hospital Affiliated to Shandong First Medical University Shandong Province Ji’nan 250021 China School of Stomatology Shandong First Medical University & Shandong Academy of Medical Sciences Shandong Province Ji’nan 250117 China Medical Science and Technology Innovation Center Shandong First Medical University & Shandong Academy of Medical Sciences Shandong Province Ji’nan 250117 China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education Shandong University Shandong Province Ji’nan 250061 China School of Materials Science and Engineering Shandong University Shandong Province Ji’nan 250061 China

Phosphate conversion coatings on metallic implants can synergistically integrate functional components and structural regulation, offering excellent biocompatibility and osteogenic activity. However, the passive oxide layer on the titanium (Ti) surface impedes the following chemical reactivity, adversely affecting the microstructure and properties of phosphate coatings. This study proposes a strategy for achieving structural optimization and properties enhancement of strontium-zinc phosphate (SrZnP) conversion coatings on Ti via regulating interface chemical reaction between coatings and Ti substrates. The results indicated that Sr²⁺ and Zn²⁺ ions-preloading (IPL) treatment enhanced the interfacial reactivity, which can further achieve crystal refinement and uniform crystal size in nucleation. In contrast, microstructural modifications on Ti substrates induced by acid etching, sandblasting, and alkali etching had minimal effects on the phase composition and crystal morphology (irregular cubic) of the SrZnP coatings. The coatings on IPL-Ti exhibited better mechanical properties and corrosion resistance. Besides, the coatings with optimized structures and surface characteristics elicited bacterial growth inhibition rates of 91.09% and 84.04% against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. Meanwhile, the crystal-refined coatings further significantly enhanced the adhesion, proliferation, and differentiation of bone marrow mesenchymal stem cells (BMSCs), proving anticipated osteogenic activity. Overall, the ions preloading strategy on variable micro/nanostructured Ti substrates facilitates the potential application of Sr/Zn-phosphate conversion coatings for repairing infected bone defects. © The Author(s) 2025.

关键词： Antibacterial capacity Interface reaction Ions preloading Osteogenic activity Sr/Zn-phosphate conversion coating Titanium

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Enhanced microwave absorption performance of high-entropy (Mo 0.2 Cr 0.2 Nb 0.2 Ti 0.2 V 0.2 ) 4 AlC 3 MAX phase through high-energy ball milling

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Ceramics International 2025年

作者： Linjing Qiao Jianqiang Bi Chengjiao Che Jiacheng Rong Shuyong Liang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education Shandong University Jinan Shandong 250061 PR China School of Materials Science and Engineering Shandong University Jinan Shandong 250061 PR China

Herein, a 413-type high-entropy (Mo 0.2 Cr 0.2 Nb 0.2 Ti 0.2 V 0.2 ) 4 AlC 3 MAX phase was successfully prepared. To elucidate the influence of high-energy ball milling on microwave absorption performance, the microstructural evolution and electromagnetic characteristics of materials subjected to varying milling durations were comprehensively investigated. Via the ball-milling process, multiple reflections, polarization loss and conductive loss are largely improved due to particle size refinement, formation of thin flakes and increased shape anisotropy. Comparative analysis revealed substantial performance enhancement in samples milled for 1 h (M1) and 3 h (M3). The unmilled powders (M0) demonstrated a minimum reflection loss (RL min ) of -23.1 dB at 4.5 mm thickness and an effective absorption bandwidth (EAB) of 2.6 GHz at 5.0 mm. In contrast, M1 achieved a RL min low to -51.8 dB at 2.3 mm, while M3 exhibited an optimal EAB of 4.1 GHz at 1.06 mm. However, extending the milling duration to 6 h resulted in diminished absorption performance compared to M1 and M3, primarily due to compromised impedance matching characteristics. Therefore, via a proper ball-milling process, microwave absorption performance of high-entropy MAX phase powders can be remarkably boosted, providing a straightforward and effective approach for performance optimization in electromagnetic wave absorption applications.

关键词： (Mo 0.2 Cr 0.2 Nb 0.2 Ti 0.2 V 0.2 ) 4 AlC 3 high-entropy MAX phase high-energy ball milling microwave absorption

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First-principles calculations of solute–vacancy interactions in aluminum

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Chinese Physics B 2020年第6期29卷 369-373页

作者： Sha-Sha Zhang Zheng-Jun Yao Xiang-Shan Kong Liang Chen Jing-Yu Qin College of Materials and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

The interactions of solute atoms with vacancies play a key role in diffusion and precipitation of alloying elements,ultimately influencing the mechanical properties of aluminum *** this study,first-principles calculations are systematically performed to quantify the solute–vacancy interactions for the 3d–4p series and the 4d–5p *** solute–vacancy interaction gradually transforms from repulsion to attraction from left to *** solute–vacancy binding energy is sensitive to the supercell size for elements at the *** behaviors of the solute–vacancy binding energy can be understood in terms of the combination and competition between the elastic and electronic ***,the electronic binding energy follows a similar trend to the total binding energy and plays a major role in the solute–vacancy interactions.

关键词： first-principles calculations solute-vacancy binding aluminum alloys

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Abnormal grain growth mechanism and inhibiting strategy by a tailored two-step solution treatment of ZK60 Mg alloy

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Journal of Magnesium and Alloys 2025年

作者： Guanghan Dang Liang Chen Jianwei Tang Yuhui Zhao Cunsheng Zhang Xiangshan Kong State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan Shandong 250061 China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University Jinan Shandong 250061 China

Mg profiles extruded through porthole die inherently contain longitudinal welds, which can readily induce the abnormal grain growth (AGG) in solution treatment at elevated temperature. Here, a strategy of two-step (primary and secondary) solution is tailored to inhibit AGG. The results indicate that AGG during primary solution can only be suppressed when the temperature drops below 300 °C, while these samples experienced AGG during secondary solution. It is interesting that the width of abnormal grain after secondary solution significantly decreases from 1,473 to 71 µm with increasing the holding time of primary solution from 3 to 84 h. This inhibiting effect results in notable enhancements in mechanical properties, where the elongation, initial fracture points, and maximum bending force are improved by 88.58 %, 32.63 %, and 128.50 %, respectively. The dislocation density and types of the precipitated phases after primary solution are the main factors for inhibiting AGG. First, the dislocation density decreases with increasing the time of primary solution, reducing the stored energy in grain interior. Second, as the primary solution time is extended, MgZn 2 phases greatly become coarsening, accompanied by a transition in their relationship with α-Mg from coherent to semi-coherent. Moreover, the quantities of Mg 4 Zn 7 (non-coherent with α-Mg) and Mg 2 Zn 3 (semi-coherent with α-Mg) undergo a substantial increase, contributing to a high interfacial energy that effectively inhibits the grain boundary migration during secondary solution.

关键词： Abnormal grain growth Solution treatment Dislocation density Precipitated phases

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key technologies of FEM simulation for phase transformation

Key technologies of FEM simulation for phase transformation

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作者： He, L. Zhao, G. Li, H. Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials Ministry of Education Shandong University Jinan Shandong 250061 China

In order to accurately evaluate the phase transformation volume fraction and hardness of quenching using the finite element method (FEM), some key technologies are given. Using these key technologies, FEM software has been developed for simulating phase transformation. The end-quenching of P20 steel was performed and FEM software was used to simulate it. Comparison of experimental results and FEM simulation results shows that the FEM results are consistent with the experimental results, and that the FEM software is reliable and accurate. FEM simulation results show that the latent heat of phase transformation has an important effect on the phase transformation volume fraction and cooling speed of quenching. © W. S. Maney & Son Ltd. 2011.

关键词： Finite element method

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