Acta Materialia最新文献_第2页

Revealing the unique evolution and splitting behavior of carbides at atomic-scale in TiAl alloys: the role of elastic interactions and chemical fluctuations

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-19 DOI: 10.1016/j.actamat.2025.121277

Li Wang, Yihao Wang, Xiaopeng Liang, Bin Liu, Junyang He, Michael Oehring, Florian Pyczak, Yong Liu

{"title":"Revealing the unique evolution and splitting behavior of carbides at atomic-scale in TiAl alloys: the role of elastic interactions and chemical fluctuations","authors":"Li Wang, Yihao Wang, Xiaopeng Liang, Bin Liu, Junyang He, Michael Oehring, Florian Pyczak, Yong Liu","doi":"10.1016/j.actamat.2025.121277","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121277","url":null,"abstract":"Cubic perovskite-Ti<sub>3</sub>AlC carbides are essential strengthening particles in TiAl alloys, especially for application above 800°C where coarsening is expected to occur. However, these carbides can decompose into small sub-particles upon extended annealing, and the underlying atomic-scale mechanisms, especially structural and compositional changes, driving this unique splitting remain unclear. This study revisits this behavior in a Ti-45Al-5Nb-0.75C alloy utilizing probe-corrected transmission electron microscopy, atom probe tomography and first-principle calculations. The results reveal that the elastic interactions significantly influence carbide evolution. While needle-like carbides transform to intact plates during aging, those in high-density regions tend to coalesce or align along elastically softest γ-matrix directions, forming low-energy plate-like carbide conglomerates. With extended annealing, periodic chemical fluctuations driven by lattice misfit, especially along the needles induce splitting. Simultaneously, a γ<sub>i</sub>-phase with a larger tetragonality and a 90°-rotated c-axis relative to the γ matrix emerges between the sub-particles, which exhibits near-zero lattice mismatch with carbides along [001], combined with mass-center shifts of carbides, further stabilizing the split configurations. This study provides atomic-scale insights into the evolution and stability of strengthening precipitates in systems with tetragonal misfit, and offers new strategies for improving creep properties of TiAl alloys by tailoring carbide configurations.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"22 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microstructure classification and the polycrystalline microstructure state space 微观结构分类与多晶微观结构状态空间

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121219

Dylan Miley, Ethan Suwandi, Benjamin Schweinhart, Jeremy K. Mason

{"title":"Microstructure classification and the polycrystalline microstructure state space","authors":"Dylan Miley, Ethan Suwandi, Benjamin Schweinhart, Jeremy K. Mason","doi":"10.1016/j.actamat.2025.121219","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121219","url":null,"abstract":"A cornerstone of materials science is that material properties are determined by their microstructure. While the community has already developed a wide variety of approaches to describe microstructure, most of these are tailored to specific material systems or classes. This work proposes a way to quantitatively measure the similarity of microstructures based on the geometry of the grain boundary network, a feature which is fundamental to and characteristic of all polycrystalline materials. Specifically, a distance on all single-phase polycrystalline microstructures is proposed such that two microstructures that are close with regard to the distance have grain boundary networks that are statistically similar in all geometric respects below a user-specified length scale. Given a pair of micrographs, the distance is approximated by sampling windows from the micrographs, defining a distance between pairs of windows, and finding a window matching that minimizes the sum of the pairwise window distances. The approach is used to compare a variety of synthetic microstructures and to develop a procedure to query a proof-of-concept database suitable for general single-phase polycrystalline microstructures.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"15 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design of Inherent Zero Poisson's Ratio Textured Piezoelectric Ceramics via Partial Auxetic Effect 基于局部形变效应的固有零泊松比织构压电陶瓷设计

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121265

Mingyang Tang, Xin Liu, Jiacong Bian, Liqing Hu, Yike Wang, Xiaodan Ren, Yan Wang, Hui Zhao, Shashank Priya, Zhuo Xu, Liwei D. Geng, Yongke Yan

{"title":"Design of Inherent Zero Poisson's Ratio Textured Piezoelectric Ceramics via Partial Auxetic Effect","authors":"Mingyang Tang, Xin Liu, Jiacong Bian, Liqing Hu, Yike Wang, Xiaodan Ren, Yan Wang, Hui Zhao, Shashank Priya, Zhuo Xu, Liwei D. Geng, Yongke Yan","doi":"10.1016/j.actamat.2025.121265","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121265","url":null,"abstract":"Materials with unusual Poisson's ratios, have attracted significant attention due to the fundamental physics and innovative applications in tailoring piezoelectric and mechanical properties. Here, we present a breakthrough in achieving near-zero Poisson's ratio in textured piezoelectric ceramics through the auxetic effect via controlled grain orientation and polarization. Theoretical analysis and phase field simulation reveal that the mechanism of zero Poisson's ratio originates from the cancellation of opposing Poisson’s ratio contributions between grains, and this design is universal. To validate this mechanism, Laser Doppler Vibrometer testing experimentally demonstrates the unique deformation configuration of the near-zero Poisson’s ratio. Furthermore, a hydrophone transducer prototype utilizing this material exhibits an intrinsic pure thickness vibration mode, significantly enhancing the sensitivity by up to 10 dB. By exploiting the intrinsic material properties, this work establishes important design strategies for novel piezoelectric materials, with broad implications for sensors, transducers, energy harvesting systems, and phased array technologies.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"28 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tribo-induced microstructural evolutions and wear mechanisms of AlCoCrFeNi2.1 eutectic high-entropy alloy at elevated temperatures 高温下AlCoCrFeNi2.1共晶高熵合金摩擦诱导的显微组织演变及磨损机制

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121272

Wei Jiang, Jian Zhou, Yang Cao, Ao Meng, Runchang Liu, Jiansheng Li, Zhuming Li, Yu Zhao, Yonghao Zhao

{"title":"Tribo-induced microstructural evolutions and wear mechanisms of AlCoCrFeNi2.1 eutectic high-entropy alloy at elevated temperatures","authors":"Wei Jiang, Jian Zhou, Yang Cao, Ao Meng, Runchang Liu, Jiansheng Li, Zhuming Li, Yu Zhao, Yonghao Zhao","doi":"10.1016/j.actamat.2025.121272","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121272","url":null,"abstract":"The tribological behaviors and wear mechanisms of the AlCoCrFeNi<sub>2.1</sub> eutectic high-entropy alloy (EHEA) were investigated in the broad temperature range 25 – 800 °C. The AlCoCrFeNi<sub>2.1</sub> EHEA exhibits a very low wear rate at 25 °C, owing to the formation of the composite type oxidation layer consisting of nanocrystals embedded in amorphous matrix. The EHEA exhibits decreasing trends for COF and stable wear rates with increasing temperature. The synergistic effect of oxidation and plastic deformation causes the formation and thickening of oxidation layer which is beneficial to wear resistance at 400 °C. At 800 °C, the high temperature enhances atomic diffusion, thus the amorphous oxide layer undergoes partial crystallization to form nano and ultrafine grains. Both the newly formed nanograins and ultrafine grains are thermally stable, and possess high hardness which can improve anti-wear performance of the alloy. This work gets insights into developing new wear-resistant alloys that is applicable in a broad temperature range, by revealing the tribo-induced surface deformation mechanisms.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"34 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthetic training data for CT image segmentation of microstructures 显微结构CT图像分割的合成训练数据

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121220

Lars Griem, Arnd Koeppe, Alexander Greß, Thomas Feser, Britta Nestler

引用次数: 0

Combining structural and chemical heterogeneities on the nanoscale to enable ductile solid solution with record-high specific strength

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121270

Qinghui Tang, Xingwang Cheng, Fan Zhang, Shipan Yin, Jingyao He, Zigao Zhang, Fei Zhang, Qingjin Zeng, Zezhou. Li, Hongmei Zhang, Junping Li, Evan Ma

{"title":"Combining structural and chemical heterogeneities on the nanoscale to enable ductile solid solution with record-high specific strength","authors":"Qinghui Tang, Xingwang Cheng, Fan Zhang, Shipan Yin, Jingyao He, Zigao Zhang, Fei Zhang, Qingjin Zeng, Zezhou. Li, Hongmei Zhang, Junping Li, Evan Ma","doi":"10.1016/j.actamat.2025.121270","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121270","url":null,"abstract":"Heterogeneous nanostructuring can strengthen metallic materials without excessive degradation in strain hardening and ductility. Here we show that the complex concentrated make-up in multi-principal element alloys makes it feasible to combine structural and chemical heterogeneities together, both at high levels and on the nanoscale, as demonstrated in a lightweight (Ti<sub>55</sub>V<sub>30</sub>Zr<sub>15</sub>)<sub>95</sub>Al<sub>5</sub> alloy (∼ 5.16 g/cm<sup>3</sup>). First, the pronounced local chemical ordering (LCO) promotes “dislocation channels” upon room-temperature rolling. This micro-deformation localization induces numerous nano-deformation bands, many of which are refined into nanocrystalline grains during extended cold rolling. Second, subsequent ageing leads to spinodal decomposition, thereby introducing compositional undulations on the nanoscale. Combined structural and chemical heterogeneities promote strengthening and strain hardening, leading to a record-high yield strength (∼ 1.7 GPa) and specific yield strength (326 MPa·cm<sup>3</sup>·g<sup>-1</sup>), while retaining a respectable elongation-to-failure over 10%, a combination unprecedented in previous lightweight alloys. Our success showcases a novel heterogeneity strategy that achieves unusually high strength without hard precipitates, opening a solid solution route towards high-performance lightweight alloys.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"180 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Direct microstructural observations and atomistic simulations on Hematite to Magnetite reduction 赤铁矿还原成磁铁矿的直接微观结构观察与原子模拟

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121269

V. Chavan , N.N. Pai , A. Prakash , P. Raut , B. Hazra , H.K. Mehtani , H. Sharma , S. Girish , S. Nag , S. Kundu , S. Basu , A. Alam , A.S. Panwar , I. Samajdar

{"title":"Direct microstructural observations and atomistic simulations on Hematite to Magnetite reduction","authors":"V. Chavan , N.N. Pai , A. Prakash , P. Raut , B. Hazra , H.K. Mehtani , H. Sharma , S. Girish , S. Nag , S. Kundu , S. Basu , A. Alam , A.S. Panwar , I. Samajdar","doi":"10.1016/j.actamat.2025.121269","DOIUrl":"10.1016/j.actamat.2025.121269","url":null,"abstract":"<div><div>This study used a combination of direct microstructural observations and atomistic simulations to examine Hematite to Magnetite reduction under molecular hydrogen. Reduction at 1123 K revealed noticeable microscopic strains, and associated grain fragmentation with increased defect densities plus residual stresses. Larger Magnetite grains exhibited deformation twinning, which reduced the transformation induced elastic-plastic deformation. Experimental orientation relationship (∼<span><math><mrow><msup><mrow><mn>50</mn></mrow><mo>∘</mo></msup><mo><</mo><mn>110</mn><mo>></mo></mrow></math></span>) and lattice correspondence-based transformation strains were also established. Atomistic simulations involved both reactive force field molecular dynamics (ReaxFF MD) and density functional theory (DFT). None of the ReaxFF parametrizations were able to fully capture all the thermodynamic and physical properties of the oxide phases. Choice of a specific parametrization was based on its ability to model the transition from α-Hematite to γ-Hematite or Maghemite. This was also shown with subsequent DFT calculations and direct microstructural observations. Experimentally, two distinct transformation paths emerged: (I) direct Hematite-to-Magnetite reduction and (II) Hematite-to-Magnetite transformation through Maghemite. Though (I) and (II) were crystallographically identical, (II) was observed <span><math><mrow><mo>≥</mo><mo>∼</mo><mn>973</mn><mi>K</mi></mrow></math></span> and had significantly more microscopic strains. Maghemite transition, and corresponding atomic shear, emerged as a key factor for transformation-induced microscopic strains, which is critical to the overall reduction kinetics. ReaxFF MD simulated this atomistic shear of experimental Maghemite formation.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121269"},"PeriodicalIF":8.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Depth-dependent microstructural observations reveal the role of thermal cycling on the formation of a hierarchical dislocation cell structure during selective laser melting of 316L stainless steel

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121271

Jinming Fan, Weiyi Wang, Yueyue Zhu, Andrew Godfrey, Hanqing Che, Xiaoxu Huang

{"title":"Depth-dependent microstructural observations reveal the role of thermal cycling on the formation of a hierarchical dislocation cell structure during selective laser melting of 316L stainless steel","authors":"Jinming Fan, Weiyi Wang, Yueyue Zhu, Andrew Godfrey, Hanqing Che, Xiaoxu Huang","doi":"10.1016/j.actamat.2025.121271","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121271","url":null,"abstract":"Detailed microstructural observations as a function of depth from the surface of the final melt pool using both transmission electron microscopy (TEM) and electron back-scatter diffraction (EBSD) have been carried out. The observations show that a well-defined dislocation cell block structure is formed during selective laser melting (SLM) of 316L stainless steel, resulting in hierarchical dislocation cell structure in interior volumes. Specifically, orientation measurements using both TEM and EBSD, combined with high-angle annular dark-field imaging, show that the evolution of the dislocation cell-block structure in SLM-prepared 316L is a combined effect of deformation, solute segregation, and thermal cycling. A segregation network forms first during solidification and then stresses due to rapid solidification/cooling coupled with melt-pool constraints result in a high density of dislocations becoming trapped at the segregation network to form dislocation cells in each melt pool. Thermal cycling of volumes below each finally-formed melt pool, from over-printed layers, then additionally leads to the formation of well-defined cell-block structure as a result of biased-dislocation accumulation associated with nascent small orientation variations in just-solidified melt pools. Depth dependent hardness measurements confirm that these cell-block boundaries directly contribute to the mechanical strength of the microstructure observed in interior (bulk) volumes of additively manufactured samples.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"626 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Elastic softening via crystallographic texture: Decoupling grain size, shape, and orientation effects in phase-transforming polycrystals 晶体织构的弹性软化：相变多晶中晶粒尺寸、形状和取向的去耦效应

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121246

Yuxuan Wang , Jianting Li , Cheng-Chao Hu , Yuxuan Chen , Yaodong Yang , Wei-Feng Rao

{"title":"Elastic softening via crystallographic texture: Decoupling grain size, shape, and orientation effects in phase-transforming polycrystals","authors":"Yuxuan Wang , Jianting Li , Cheng-Chao Hu , Yuxuan Chen , Yaodong Yang , Wei-Feng Rao","doi":"10.1016/j.actamat.2025.121246","DOIUrl":"10.1016/j.actamat.2025.121246","url":null,"abstract":"<div><div>The elastic softening of polycrystalline phase-transforming materials (PTMs) is intricately linked to their microstructural characteristics, yet the individual and coupled roles of grain size, shape, and orientation remain inadequately resolved. Here we employed 3D phase-field simulations on an iron-nickel alloy with strong elastic anisotropy to decouple these effects. It was demonstrated that crystallographic texture dominates elastic softening, reducing the modulus by up to 75 % when grains align along soft crystallographic orientations. Grain size exerts negligible influence on the elastic modulus of coarse- and fine-grained PTMs under small loads but critically governs phase transition hysteresis under large deformation. Morphological anisotropy introduced by elongated or flattened geometries of grains modifies the modulus by ∼10 %. Nonlinear interactions between texture and grain morphology further modulate softening magnitudes, deviating from linear superposition predictions. By decoupling these effects, it is suggested that texture engineering via orientation alignment is the most effective pathway for designing PTMs with tailored elastic softening. This work provides a microstructure-property map for designing PTMs with desired elasticity.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121246"},"PeriodicalIF":8.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Machine learning of microstructure–property relationships in materials leveraging microstructure representation from foundational vision transformers 利用基础视觉变压器的微观结构表示的材料微结构-性能关系的机器学习

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121217

Sheila E. Whitman, Marat I. Latypov

{"title":"Machine learning of microstructure–property relationships in materials leveraging microstructure representation from foundational vision transformers","authors":"Sheila E. Whitman, Marat I. Latypov","doi":"10.1016/j.actamat.2025.121217","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121217","url":null,"abstract":"Machine learning of microstructure–property relationships from data is an emerging approach in computational materials science. Most existing machine learning efforts focus on the development of task-specific models for each microstructure–property relationship. We propose utilizing pre-trained foundational vision transformers for the extraction of task-agnostic microstructure features and subsequent light-weight machine learning of a microstructure-dependent property. We demonstrate our approach with pre-trained state-of-the-art vision transformers (CLIP, DINOv2, SAM) in two case studies on machine-learning: (i) elastic modulus of two-phase microstructures based on simulations data; and (ii) Vicker’s hardness of Ni-base and Co-base superalloys based on experimental data published in literature. Our results show the potential of foundational vision transformers for robust microstructure representation and efficient machine learning of microstructure–property relationships without the need for expensive task-specific training or fine-tuning of bespoke deep learning models.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"6 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0