Baoyu Luo, Yanhui Guo, Linghuan Pang, Xin Liu, Mingzhe Cui, Bin Fu
{"title":"Excellent combinations of strength-ductility and corrosion resistance in SAF 2205 duplex stainless steel with multi-scale grain distribution","authors":"Baoyu Luo, Yanhui Guo, Linghuan Pang, Xin Liu, Mingzhe Cui, Bin Fu","doi":"10.1016/j.matchar.2024.114490","DOIUrl":"10.1016/j.matchar.2024.114490","url":null,"abstract":"<div><div>In this work, a multi-scale grain structure was obtained in SAF 2205 duplex stainless steel (DSS) by severe deformation and short-term annealing process. The influence of this structure on the mechanical properties and electrochemical behavior is systematically investigated. Experimental results indicate that the sample subjected to short-term annealing at 1000 °C (SA-1000 °C) exhibits the best comprehensive properties, with a yield strength (YS) of 652.6 MPa and an elongation (EL) of 39.9 %. Both strength and ductility surpass those of the original sample and long-term annealed (LA-1000 °C) samples. The strength-ductility product is increased by 32 % compared to the original sample and by 18 % compared to the LA-1000 °C sample. The increase in YS is predominantly attributed to dislocation strengthening and grain refinement strengthening, and the heterogeneous microstructure leads to good ductility. Moreover, the multi-scale distribution of the grain structure exhibits enhanced corrosion resistance due to the increased low-Σ grain boundaries and the promotion of stable passivation film formation by a limited number of defects, thereby mitigating the corrosion rate.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114490"},"PeriodicalIF":4.8,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of TiC and Ni addition on densification and mechanical properties of microwave sintered ZrB2 based composites","authors":"Ankur Sharma, Anish Upadhyaya","doi":"10.1016/j.matchar.2024.114481","DOIUrl":"10.1016/j.matchar.2024.114481","url":null,"abstract":"<div><div>The effects of TiC (10–30 vol%) and Ni (1–2 vol%) incorporation on densification, microstructural evolution and mechanical properties of microwave sintered ZrB<sub>2</sub> matrix-based composites were investigated in the present study. The findings reveal that TiC addition significantly improves the densification of ZrB<sub>2</sub> based composites, while the inclusion of Ni further improves densification of ZrB<sub>2</sub>–20 vol% TiC composite by reducing porosity and restricting the grain growth of both ZrB<sub>2</sub> and TiC phases. Additionally, the highest Vickers hardness of 22.25 ± 1.33 GPa and compressive strength of 1556.2 ± 40.17 MPa were obtained for the ZrB<sub>2</sub>–20 vol% TiC composite due to lower porosity, lower grain size and higher TiC diffusion in the ZrB<sub>2</sub> matrix. The fracture toughness enhanced with TiC and Ni addition and the maximum fracture toughness was observed as 6.66 ± 0.47 MPa.m<sup>0.5</sup> along with the highest critical energy release rate of 95.16 ± 11.68 J/m<sup>2</sup> for the ZrB<sub>2</sub>–20 vol% TiC-2 vol% Ni composite owing to the activation of toughening mechanisms like crack bridging, crack deflection and open pores as crack deflectors. Nanoindentation studies revealed significant improvements in elastic modulus and stiffness with the addition of TiC. The maximum elastic modulus and stiffness were observed as 482.91 ± 36.36 GPa and 237.24 ± 20.28 μN/nm for ZrB<sub>2</sub>–20 vol% TiC composite. The study highlights the potential of incorporating metallic additives with secondary reinforcements to enhance the mechanical properties and microstructures of ZrB<sub>2</sub> matrix, making them potential materials for high-temperature applications such as control surfaces, nose caps and leading edges of supersonic aircrafts.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114481"},"PeriodicalIF":4.8,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhimin Liang , Zhuobin Sun , Dan Liu , Xiao Yang , Yongmei Liang , Dianlong Wang , Dejun Yan , Yuzhong Rao , Kehong Wang
{"title":"Enhancing mechanical and corrosion properties of Al-Zn-Mg-Cu alloy through electropulsing and aging alternate treatment","authors":"Zhimin Liang , Zhuobin Sun , Dan Liu , Xiao Yang , Yongmei Liang , Dianlong Wang , Dejun Yan , Yuzhong Rao , Kehong Wang","doi":"10.1016/j.matchar.2024.114485","DOIUrl":"10.1016/j.matchar.2024.114485","url":null,"abstract":"<div><div>The contradiction between mechanical and corrosion properties restricts the further research and application of Al-Zn-Mg-Cu alloy. Studies report a new technique, electropulsing and aging alternate treatment (EPAAT), including twice electropulsing and aging treatment, to solve this contradiction by precisely controlling the intragranular precipitates and grain boundary precipitates (GBPs). The results show that the grain boundary precipitates (GBPs, η) are discontinuous and the intragranular precipitates (η’) are not coarsened after EPAAT. The precise regulation of precipitated phase by EPAAT can be attributed the differing effect of electropulsing current on the GBPs and the intragranular precipitates. Utilize electropulsing primary treatment to obtain the supersaturated solid solution. Following natural aging, the small continuous phases at the grain boundary and the GP zones within the grain were precipitated again. The small continuous GPBs of the sample diffuse along the grain boundaries and become discontinuously distributed, while the GP zones within the grain dissolve with under the electropulsing secondary treatment. After artificial aging, the intragranular phase is fully precipitated, yet the GBPs remain unchanged, thereby achieving phase regulation. Consequently, the <em>i</em><sub>corr</sub> of Al-Zn-Mg-Cu alloy decreases from 28 to 5.87 μA/cm<sup>2</sup> and the tensile strength increases from 511 MPa to 524 MPa. The EPAAT technology realizes the accurate treatment of Al-Zn-Mg-Cu alloys and provides a new solution for improving strength and corrosion properties.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114485"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ji Liu , Yugang Miao , Ruizhi Wu , Chao Wei , Yuyang Zhao , Yifan Wu , Qingwen Deng
{"title":"Improved material properties of wire arc additively manufactured Al-Zn-mg-cu alloy through severe deformation interlayer friction stir processing and post-deposition heat treatment","authors":"Ji Liu , Yugang Miao , Ruizhi Wu , Chao Wei , Yuyang Zhao , Yifan Wu , Qingwen Deng","doi":"10.1016/j.matchar.2024.114487","DOIUrl":"10.1016/j.matchar.2024.114487","url":null,"abstract":"<div><div>In this study, Al-Zn-Mg-Cu alloys were prepared by wire arc additive manufacturing (WAAM) combined with interlayer friction stir processing (IFSP). To enhance the FSP region, an improved stirring pin was designed to broaden the stir zone effectively. Moreover, the effects of typical T6 and T73 heat treatments on the microstructure and mechanical properties of as-deposited (AS) specimen were meticulously investigated. The results indicated that heat treatments had minimal impact on grain size, dislocation density, and texture strength, but significantly altered the type, size, and distribution of precipitates. The differences in strength were primarily attributed to precipitation strengthening rather than grain boundary or dislocation strengthening. Following T6 heat treatment, the precipitates were predominantly η’, which were smaller in size and exhibited a significantly increased number density compared to AS specimen. Therefore, the average yield strength (YS) and ultimate tensile strength (UTS) increased by 39.51 % (500.21 MPa) and 15.84 % (584.26 MPa), respectively. In contrast, T73 treatment caused a substantial number of fine η’ to transform into coarser η, leading to a significant decrease in precipitate number density. Consequently, compared to T6 specimen, the average YS and UTS decreased by 47.19 % and 13.13 %, respectively.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114487"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingyao Wang , Qinghua Lu , Peilei Zhang , Hua Yan , Haichuan Shi , Tianzhu Sun
{"title":"Microstructure evolution and mechanical properties of selective laser melting fabricated hybrid particle reinforced AlSi10Mg composites","authors":"Xingyao Wang , Qinghua Lu , Peilei Zhang , Hua Yan , Haichuan Shi , Tianzhu Sun","doi":"10.1016/j.matchar.2024.114483","DOIUrl":"10.1016/j.matchar.2024.114483","url":null,"abstract":"<div><div>(SiC+TiB<sub>2</sub>)/AlSi10Mg composite powders with 5 wt% micro-SiC particles and 1.5 wt% nano-TiB<sub>2</sub> particles were prepared by high energy ball milling, and hybrid particle reinforced aluminum matrix composites (AMCs) were fabricated by SLM. This study systematically investigated the effects of SiC and TiB<sub>2</sub> particles on the phase composition, microstructure evolution, grain crystallization, and mechanical properties. The machanisms of potential strengthening and fracture mechanisms were revealed. The tribological behaviors of the hybrid particle reinforced AlSi10Mg composites under different friction conditions were explored as well. The results show that the 1.5 wt% nano-TiB<sub>2</sub> particles provided sufficient nucleation sites for grain growth, completely transforming from coarse columnar to fined equiaxed grains. The average grain size decreases from 7.98 μm to 3.34 μm, and the texture is significantly weakened, which is beneficial to the homogenization of the microstructure, thereby improving the mechanical properties of the SiC/AlSi10Mg composites. The (SiC+TiB<sub>2</sub>)/AlSi10Mg composites showed a high ultimate tensile strength (∼ 489.1 MP), hardness (172.2 HV) and elongation of 8.2 %. The enhancement of mechanical properties was attributed to Orowan strengthening, fine grain strengthening, and load-bearing strengthening. Due to the Si precipitates and fine microstructure, a low wear rate of 0.50 × 10<sup>−5</sup> g/m was obtained, 10.7 % lower than that of SLM formed SiC/AlSi10Mg composites. The friction process is affected by abrasive wear, adhesive wear and delamination wear. It is aspired that the current approach can provide guidance for the design of new alloy systems with excellent performance.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114483"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu Xiao , Song-Wei Wang , Hong-Wu Song , Shuai-Feng Chen , Qi Yu , Shi-Hong Zhang
{"title":"La drives the remarkable strength enhancement of the Cu-Cr-Zr alloy through traditional thermo-mechanical treatment","authors":"Yu Xiao , Song-Wei Wang , Hong-Wu Song , Shuai-Feng Chen , Qi Yu , Shi-Hong Zhang","doi":"10.1016/j.matchar.2024.114488","DOIUrl":"10.1016/j.matchar.2024.114488","url":null,"abstract":"<div><div>The Cu-1Cr-0.1Zr alloy with different La addition (0 %, 0.07 % and 0.14 wt%) was processed using industry suitable two-step cold rolling and aging treatment to achieve superior strength and electrical conductivity. The role of La addition on the microstructure evolution and comprehensive properties of the Cu-1Cr-0.1Zr alloy is investigated during the second rolling and subsequent aging stages. During pre-aging process, the presence of La in the Cu-1Cr-0.1Zr-0.07La alloy led to formation of smaller precipitate sizes compared to La-free Cu-1Cr-0.1Zr alloy. This facilitates a stronger cut interaction between dislocations and precipitates during secondary rolling process, which promotes the redissolution of precipitates into Cu matrix and thus results in a larger decline of 44.72 % ICAS for the electrical conductivity of Cu-1Cr-0.1Zr-0.07La alloy. After post-aging treatment, precipitates are newly formed with increased number and refined size of Cr precipitates with maintaining a coherent relationship with the matrix. Besides, the addition of La promotes Cr-rich phase precipitation and dislocation accumulation. Resultantly, remarkable increase in tensile strength by 11 % with the addition of 0.07wt%La. While, the 0.14La added alloy exhibits comprehensive properties of tensile strength 600 MPa and electrical conductivity 80.08 %IACS after aging at 440 °C for 180 min. The increase in strength was primarily attributed to precipitation strengthening and dislocation strengthening. This work provides new kinds of Cu-1Cr-0.1Zr alloy and industrial suitable thermo-mechanical treatment for fabricating high performance cooper alloy sheets.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114488"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chenyu Zhai , Zhimin Yang , Shilin Feng , Yongfu Cai , Zhenhua Han , Hongyan Wang , Chen Chen , Tan Wang , Shaojie Wu , Haimei Li , Ran Wei
{"title":"A novel corrosion resistant NiFeCrAlTi eutectic high entropy alloy with high strength and ductility","authors":"Chenyu Zhai , Zhimin Yang , Shilin Feng , Yongfu Cai , Zhenhua Han , Hongyan Wang , Chen Chen , Tan Wang , Shaojie Wu , Haimei Li , Ran Wei","doi":"10.1016/j.matchar.2024.114479","DOIUrl":"10.1016/j.matchar.2024.114479","url":null,"abstract":"<div><div>We present a novel corrosion resistant Ni<sub>42.6</sub>Fe<sub>24.6</sub>Cr<sub>16.4</sub>Al<sub>13.4</sub>Ti<sub>3</sub> eutectic high entropy alloy (EHEA), which consists of FCC(L1<sub>2</sub>) phase and BCC(L2<sub>1</sub>) phase. The FCC and BCC phases contain numerous nano-precipitates, with sizes of ∼10 nm and 80 nm, respectively. The as-cast EHEA exhibits exceptional mechanical properties with a yield strength of ∼730 MPa, an ultimate tensile strength of 1220 MPa and elongation of 25 %, surpassing those observed in other as-cast EHEAs. The excellent mechanical properties are attributed to the extensive dislocation activities and precipitation strengthening in both BCC and FCC phases, as well as hetero-deformation induced (HDI) strengthening. Besides, the Kurdjumov-Sachs (K<img>S) orientation relationship between adjacent phases promotes the cooperative deformation of both constituent phases, thereby enhancing the ductility of the EHEA.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114479"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Clémence Fontaine , Lola Lilensten , Dalibor Preisler , Josef Strasky , Mathilde Laurent-Brocq , Philippe Chevallier , Amélie Fillon , Daniel Galy , Milos Janecek , Frédéric Prima
{"title":"Local characterization of mechanical properties and deformation mechanisms of SPS graded strain-transformable Ti-Nb alloy","authors":"Clémence Fontaine , Lola Lilensten , Dalibor Preisler , Josef Strasky , Mathilde Laurent-Brocq , Philippe Chevallier , Amélie Fillon , Daniel Galy , Milos Janecek , Frédéric Prima","doi":"10.1016/j.matchar.2024.114482","DOIUrl":"10.1016/j.matchar.2024.114482","url":null,"abstract":"<div><div>Compositional boundaries of activity regarding transformation-induced plasticity and mechanical twinning (TRIP/TWIP) in Ti-Nb alloying system is determined by a novel methodology using chemically graded samples prepared by Spark Plasma Sintering. Presented methods of characterization include nanoindentation and microindentation testing complemented by EBSD analyses. The link between composition, microstructure, deformation mechanisms and mechanical properties can be established. Applied to the Ti-Nb system for a proof of concept, both the identification of local mechanical properties with respect to composition, and the refinement of the compositional ranges within which the different deformation mechanisms occur can be obtained. The graded sample ranging from 14 at.% to 34 at.% Nb is studied. TRIP/TWIP activity is resolved by EBSD in range 17 to 24 at.% of Nb, which is significantly lower than the results from the literature. This difference is attributed to the presence of interstitial oxygen (2470 ± 60 weight ppm).</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114482"},"PeriodicalIF":4.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gaopeng Xu , Ting Wu , Ruili Liu , Yunqian Zhen , Funian Han , Kui Wang , Hongbin Xie , Hao Wang , Haiyan Jiang , Wenjiang Ding
{"title":"Architecture of a remelted layer with the nano-lamellar structure at the surface of FeB materials via laser remelting to resist liquid aluminum corrosion","authors":"Gaopeng Xu , Ting Wu , Ruili Liu , Yunqian Zhen , Funian Han , Kui Wang , Hongbin Xie , Hao Wang , Haiyan Jiang , Wenjiang Ding","doi":"10.1016/j.matchar.2024.114480","DOIUrl":"10.1016/j.matchar.2024.114480","url":null,"abstract":"<div><div>In this work, a significant enhancement of corrosion resistance of Fe-B materials in liquid Al (750 °C), with a corrosion rate one order of magnitude lower than that of H13 die steel, has been achieved by constructing nano-lamellar structures in the matrix. Results indicate that the nano-lamellar structure can not only effectively obstruct the interdiffusion between the Al and Fe atoms, restricting the growth of corrosion layers, but also accommodate sufficient growth and thermal stresses, suppressing the spallation of corrosion products. Furthermore, the ceramic nanoparticles in-situ formed in the nano-lamellar structure can inhibit the inward diffusion of Al atoms, greatly enhancing the corrosion resistance of α-Fe matrix. Besides, they also provide a robust pinning effect on the corrosion interface, improving the adhesion strength of corrosion products with the matrix. The architecture of nano-lamellar structure with nanoparticles may provide a novel strategy against liquid Al corrosion and shed new light on the development of corrosion-resistant materials.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114480"},"PeriodicalIF":4.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Precipitation behavior of Al-Zn-Mg-Cu alloys with the coupled soft/hard micro-scale areas and its effect on properties","authors":"Jinming Zhi , Mingxing Guo , Wen Meng , Wei Zhou , Linzhong Zhuang , Huafen Lou","doi":"10.1016/j.matchar.2024.114476","DOIUrl":"10.1016/j.matchar.2024.114476","url":null,"abstract":"<div><div>A novel thermomechanical processing route was developed to prepare Al-Zn-Mg-Cu alloys containing heterostructures with coupled soft/hard micro-scale areas. The heterostructure gives an effect on the subsequent precipitation behavior of alloys. Importantly, the tensile strengths, elongation and corrosion resistance of grain boundaries of the #3 alloy with an appropriate coupled distribution of soft/hard micro-scale areas are all greatly improved compared with the alloy with the homogeneous structure. Based on the detailed microstructure characterization, the corresponding strengthening and corrosion resistance mechanisms of alloys with heterostructure have been established in this paper.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114476"},"PeriodicalIF":4.8,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142526369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}