Materials Characterization最新文献

{"title":"Study on high temperature tensile constitutive behavior and deformation mechanism of Ti-47.5Al-2.5 V-1.0Cr-0.2Zr alloy","authors":"Xuejian Lin ,&nbsp;Xin Liu ,&nbsp;Hongjun Huang ,&nbsp;Bowen Zheng ,&nbsp;Kai Du ,&nbsp;Xiaojiao Zuo ,&nbsp;Xiaoguang Yuan","doi":"10.1016/j.matchar.2024.114594","DOIUrl":"10.1016/j.matchar.2024.114594","url":null,"abstract":"<div><div>The high temperature tensile test of Ti-47.5Al-2.5 V-1.0Cr-0.2Zr alloy was carried out by electronic universal testing machine under the condition of 750–900 °C/10⁻⁵–10⁻³ s⁻¹. The hot tensile stress-strain curves were analyzed, and the constitutive model under hot tensile conditions was established. The microstructure transformation rule and deformation mechanism during tensile process were determined. The results show that the hot tensile curve is longer in the steady-state flow stage corresponding to lower strain rate and higher tensile temperature, the true stress declines and the elongation at break increases. The constitutive equation was established based on the tensile curve data, and the corresponding thermal activation energy was 310.3 kJ/mol. As the rise of tensile temperature and the decline of strain rate, the proportion about cross-layer fracture in the tensile fracture morphology decreases, the number of dimples increases, more lamellar structures change into recrystallized structures, and the softening effect of the alloy is more obvious. The dislocation deformation mechanism mainly includes the existence of dislocation slip and climb, dislocation intersection and dislocation ring or dislocation network formation. Twinning deformation is also another important mechanism of high temperature tensile deformation of TiAl alloy. Twins are formed in parallel with each other, so that the deformation can be further carried out. The dislocations and twins in the deformed microstructure will provide nucleation conditions for recrystallized grains. The dynamic recrystallization(DRX) grains are preferentially formed around the grain boundary and the vicinity of dislocation and twin is also preferred nucleation site for DRX. The DRX behavior is the main softening mechanism, and DRX size and volume fraction corresponding to lower tensile rate and higher tensile temperature are larger.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114594"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757455","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":"Effect of warm rolling on microstructure evolution and mechanical properties of a Ni–W–Co–Ta medium-heavy alloy","authors":"Jin-Jin Tang ,&nbsp;Yi Xiong ,&nbsp;Xiao-Qin Zha ,&nbsp;Xiu-Ju Du ,&nbsp;Yong Li ,&nbsp;Feng-Zhang Ren ,&nbsp;Shubo Wang","doi":"10.1016/j.matchar.2024.114591","DOIUrl":"10.1016/j.matchar.2024.114591","url":null,"abstract":"<div><div>The microstructure and mechanical properties influenced by warm rolling in a Ni–W–Co–Ta medium-heavy alloy (MHA) is studied in this work in order to explore the optimal processing-microstructure-property paradigm. The results show that the initially equiaxed grains evolves into a fibrous structure, aligned with the rolling direction, as the rolling progresses. Texture analysis reveals a transition from Brass-type component to a mixed texture component of Brass-type and Copper-type with increasing deformation. Concurrently, dislocation density rise, and nano deformation twins and precipitation of Ni₄W take place. The strength is significantly enhanced. However, the trade-off between strength and ductility still persists. An optimal combination of strength and ductility has been achieved at a 50 % rolling deformation. These demonstrate that warm rolling is an effective processing route for manufacturing high-strength and still ductile MHA.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114591"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747386","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":"Ferrite formation and decomposition in 316H austenitic stainless steel electro slag remelting ingot for nuclear power applications","authors":"Yang Wang ,&nbsp;Chao Chen ,&nbsp;Ruijie Ren ,&nbsp;Zhixuan Xue ,&nbsp;Haozheng Wang ,&nbsp;Yunzhe Zhang ,&nbsp;Junxian Wang ,&nbsp;Jian Wang ,&nbsp;Lei Chen ,&nbsp;Wangzhong Mu","doi":"10.1016/j.matchar.2024.114581","DOIUrl":"10.1016/j.matchar.2024.114581","url":null,"abstract":"<div><div>316H austenitic stainless steel used in nuclear power has higher requirements for material magnetism, and the main magnetic phase is ferrite. Thus, the ferrite content in 316H steel castings needs to be strictly controlled. This study investigated the ferrite phases in 316H austenitic stainless steel electro-slag remelting (ESR) ingot used in nuclear power applications. The morphology, content and decomposition of ferrite as well as microsegregation in 316H ESR ingot are studied by optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA). The solidification process is calculated by thermodynamic calculation using Thermo-Calc. Besides, the empirical chromium and nickel equivalent formulas and phase stability diagram are used for prediction of the solidification mode and ferrite content. The experiment results show that the ferrite morphology changes greatly in the direction of the thickness of ESR ingot. From surface to center of the ESR ingot, the ferrite morphology varies as granular → short rod-shaped → blocky → skeletal → parallel short rod-like + network-like. The ferrite content in the thickness direction of the electroslag ingot varied from 1.92 to 3.57 %, showing an “A” shape distribution. There are three kinds of decomposition behavior of ferrite: decomposition into Sigma phase and austenite phase by the eutectoid reaction, transformation into Chi phase in regions enriched with high Mo element along grain boundaries, and direct transformation into secondary austenite phase. In addition, the thermodynamic calculation and most of empirical formulas predicts the solidification mode is FA mode. From the microstructure analysis, the solidification mode of ESR ingots change from AF mode to FA mode from surface to center. Furthermore, the formulas proposed by Hull provides most accurate predictions results in ferrite content.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114581"},"PeriodicalIF":4.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721585","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":"Enhancement of mechanical and electrical properties of copper matrix composites by different types of carbon nanotubes","authors":"XianFeng Zhao,&nbsp;XiaoNa Ren,&nbsp;ZhiPei Chen,&nbsp;ChangChun Ge","doi":"10.1016/j.matchar.2024.114575","DOIUrl":"10.1016/j.matchar.2024.114575","url":null,"abstract":"<div><div>Copper-based composites with carbon nanotubes (CNTs) as the reinforcing phase possess excellent comprehensive mechanical and electrical properties and have received widespread attention in the electronics industry in recent years. However, a handful of studies concerns CNTs reinforced copper matrix composites with different wall layers. In this study, multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were selected. An improved molecular-level blending method was exploited to produce copper matrix composites reinforced by MWCNTs and SWCNTs in our study. The characterization results showed that the copper coated MWCNTs and SWCNTs were evenly distributed in the copper matrix and ensured the connection structure tightly between CNTs as heterogeneous strengthening factors and the copper matrix. Meanwhile, in the mechanical property test, the MWCNTs/Cu composite material had the highest tensile strength (262.5 MPa), which was 23.6 % higher than pure copper and 12.6 % higher than the SWCNTs/Cu composite materials. In addition, in the electrical performance test, MWCNTs/Cu and SWCNTs/Cu composites all possessed excellent electrical conductivity, 95 % IACS and 96 % IACS, respectively. The research work in this paper can be extended to the development of ultra-light copper and copper alloy electronic devices and provide a reference for future research on CNTs augmented metal matrix composites.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114575"},"PeriodicalIF":4.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721586","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":"Heterogeneous Fe-Mn-Al-C lightweight steel breaking the strength-ductility trade-off via high-temperature warm rolling process","authors":"Hua Wang ,&nbsp;Yongping Liang ,&nbsp;ShiYu Hao ,&nbsp;Junfeng Wang ,&nbsp;Hao Shi","doi":"10.1016/j.matchar.2024.114571","DOIUrl":"10.1016/j.matchar.2024.114571","url":null,"abstract":"<div><div>In this study, a lightweight heterogeneous Fe-6Mn-4.1Al-0.41C-0.62Si-0.2 V (wt%) steel with the synergy of high tensile strength and ductility was achieved by warm-rolling at 850 °C with a 93 % thickness reduction, namely, an ultimate tensile strength of 1.18 GPa, a total elongation of 35.4 %, and the product of strength and elongation (PSE) of 41.9 GPa%. The microstructure of the investigated steel consists of δ-ferrite (δ-F), retained austenite (RA), inter-critical ferrite (IF) and Fe₃C precipitates. The moderate stability of RA, induced by its different morphologies (<em>i.e.</em>, lath, block shape), provides a discontinuous and local phase transformation-induced plasticity (TRIP) effect that contributes to the excellent work hardening ability. Meanwhile, the isomeric hetero deformation induced (HDI) strengthening between RA and δ-F, and between RA and IF, further enhances the investigated steel's high strength and ductility. In addition, our results indicate that increasing the rolling temperature results in the increment of RA, while increasing the rolling reduction (<em>i.e.</em>, 5 % at 800 °C) has a limited effect on the formation of RA.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114571"},"PeriodicalIF":4.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721332","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":"Cavity self-healing mechanism at the interface of high-Cr ferritic steel/austenitic steel dissimilar diffusion-bonded joint during cyclic phase transformation treatment","authors":"Chenxi Liu,&nbsp;Yingying Wang,&nbsp;Ruijiang Chang,&nbsp;Qianying Guo,&nbsp;Ran Ding,&nbsp;Yongchang Liu","doi":"10.1016/j.matchar.2024.114569","DOIUrl":"10.1016/j.matchar.2024.114569","url":null,"abstract":"<div><div>In this work, cyclic phase transformation treatment (CPTT) was developed to achieve self-healing of interfacial voids in high-Cr ferritic steel/austenitic steel dissimilar diffusion-bonded joints. The evolution of voids was analyzed based on microstructural characteristics, and mechanical properties of joints were assessed through lap-shear tensile tests. The results indicate that, in contrast to isothermal heat treatment (IHT), CPTT significantly enhances efficiency of cavity healing, leading to substantial improvements in both interface bonded ratio and shear performance of joints. By considering equivalent interfacial internal stress, a kinetic model for cavity healing was proposed, incorporating coupled the interface and surface diffusion, and the power-law creep mechanism. Simulation results demonstrate that diffusion predominates during cavity healing with negligible contribution of plastic flow. The actual cavity healing can be divided into two stages: in initial stage the large penny-shaped cavities become shorter in length with negligible change of height, while in the final stage, nearly circular voids shrinkage with a significant decrease of void size due to the enhanced effect of local surface diffusion. Moreover, it suggests that tensile internal stresses can impede healing or even promote residual void growth. Conversely, normal compressive internal stresses within cavity healing zone induced by the cyclic α↔γ phase transformation during CPTT intensify chemical gradients around void neck. This promotes accelerated atomic diffusion adjacent to void neck region, thereby resulting in a notable reduction in the duration required for complete cavity healing.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114569"},"PeriodicalIF":4.8,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721333","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":"Strength and plasticity coordination improvement mechanism in network structure TiBw/TA15 composite via multi-DOF forming","authors":"Jishi Zhang ,&nbsp;Xinghui Han ,&nbsp;Xuan Hu ,&nbsp;Lin Hua ,&nbsp;Fang Chai ,&nbsp;Baoyi Su ,&nbsp;Xinxin Fan","doi":"10.1016/j.matchar.2024.114564","DOIUrl":"10.1016/j.matchar.2024.114564","url":null,"abstract":"<div><div>TiBw/TA15 composite with network TiB whisker (TiBw) reinforcement architecture, exhibits high strength but limited plasticity, presenting a significant challenge in enhancing the plasticity of TiBw/TA15 composites. In the current work, strength and plasticity coordination improvement of TiBw/TA15 composite is achieved through the application of multi-degrees of freedom forming (multi-DOF forming) technology. The α phase spheroidization behaviour and strength-plasticity coordination improvement mechanisms are investigated. The results elucidate that increasing deformation amount through multi-DOF forming leads to more pronounced α phase spheroidization and refinement. This effect is attributed to the generation of substantial strain along the deformation path, particularly in the regions where hard TiBw particles rotate (i.e., the tips of TiBw). Additionally, the impediment of dislocation movement by TiBw causes dislocations to accumulate along these rotation regions via single slip and cross slip mechanisms, thereby accelerating the α phase spheroidization process. Furthermore, with increasing deformation amount, the strength and plasticity are coordinately improved. The tensile strength and elongation increase linearly from 972 MPa to 1239 MPa (increased by 27.5 %) and from 5.6 % to 7.9 % (increased by 41.1 %) as the deformation condition advanced from the sintered state to the 40 % deformation condition, respectively. Improved plasticity can be attributed to the refinement of grains and TiBw, promoting more uniform plastic deformation and reducing stress concentrations during tensile testing. The strengthening mechanisms encompass load transfer strengthening facilitated by TiBw, grain refinement strengthening and dislocation pinning effect caused by TiBw.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114564"},"PeriodicalIF":4.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723693","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":"Liquation cracking resistance and microstructural characteristics leading to low susceptibility in borated stainless steels for neutron absorbers","authors":"Gitae Park ,&nbsp;Yongjoon Kang ,&nbsp;Chan Kyu Kim ,&nbsp;Seolbin Jeong ,&nbsp;Jung-Min Kim ,&nbsp;Sang Woo Song","doi":"10.1016/j.matchar.2024.114568","DOIUrl":"10.1016/j.matchar.2024.114568","url":null,"abstract":"<div><div>This study presents a comprehensive investigation of liquation cracking resistance in Borated Stainless Steels (BSSs) within the compositional range of ASTM A887 grade. Thermomechanical simulation was utilized to evaluate their hot cracking characteristics, providing valuable insights into the microstructural aspects. Cylindrical specimens were prepared from the three types of hot-rolled BSS sheets with varying boron content. The Gleeble simulator was employed to conduct on-heating and on-cooling hot ductility tests, specifically replicating the thermal cycles of the weld heat-affected zone, with a focus on the partially melted zone. The reduction in area was quantified as a measure of ductility, and in-depth microstructural analysis was conducted to unveil the underlying mechanisms contributing to liquation cracking susceptibility. BSSs corresponding to 304B3, B4, and B5 generally exhibited a lower brittle temperature range, and an increase in boron content was found to slightly reduce cracking susceptibility. This research clarifies the issues of low liquation cracking susceptibility in BSSs, offering valuable insights that significantly enhance their industrial performance as neutron absorbers in disposal of used nuclear fuel and nuclear power plants.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114568"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723688","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":"High-strength stainless steel joints achieved by co-regulation mechanism of phosphide dispersed distribution and γ-phase generation","authors":"Rui Xu ,&nbsp;Tong Wu ,&nbsp;Xinyue Li ,&nbsp;Xinfei Zhang ,&nbsp;Jingze Cui ,&nbsp;Fugang Lu ,&nbsp;Shuye Zhang ,&nbsp;Ce Wang ,&nbsp;Panpan Lin ,&nbsp;Peng He","doi":"10.1016/j.matchar.2024.114565","DOIUrl":"10.1016/j.matchar.2024.114565","url":null,"abstract":"<div><div>A novel iron-based filler FeCr18Ni10Si6P6 was designed to address the inherent limitations of joint strength reduction caused by the formation of the continuous brittle phase in the diffusion affected zone (DAZ) during traditional iron-based filler joints. The influence of process parameters on the microstructure evolution and mechanical properties of the joints was subjected to a comprehensive examination. The results indicated that the diffusion of Cr would result in the formation of α-phase in DAZ of the joints, which predominantly solidified most of the P atoms. This ultimately led to the precipitation of phosphide in the form of fine needles, enhancing the strength of the joints and altering the joint fracture region from DAZ to athermal solidified zone (ASZ). The joint strength peaked at 177 MPa when brazed at 1120 °C for 15 min, which is 2.6 times higher than that of traditional iron-based filler metals used in bonding. This filler metal presents a novel approach to the low-cost and high-quality joining of stainless steel.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114565"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723136","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":"Characteristic of phase precipitation and its role in grain evolution and mechanical properties of high entropy alloy","authors":"Shaolong Song,&nbsp;Xiaodi Wang,&nbsp;Zhe Zhang,&nbsp;Xuechong Ren","doi":"10.1016/j.matchar.2024.114563","DOIUrl":"10.1016/j.matchar.2024.114563","url":null,"abstract":"<div><div>High entropy alloys have attracted great interests in research due to the novel designing concept. In this work, the microstructural evolution of Al_0.3CoCrFeNi high entropy alloy after cold rolling and annealing treatment (at 750 °C, 850 °C and 950 °C) was investigated by scanning electron microscopy and electron backscatter diffraction. It was found that this alloy was subject to recrystallization, grain growth and abnormal grain growth, accompanied by second phase precipitation with increasing annealing time. Precipitates were formed in non-recrystallized areas at low temperatures, which delayed recrystallization and subsequent grain growth. On the other hand, precipitates were detected in both recrystallized grain interiors and boundaries at all temperatures after recrystallization, and with increasing annealing time, their total volume fractions firstly increased, then decreased and finally remained nearly unchanged. The grain growth was highly impeded by precipitates, e.g., the grain size was only ∼1.41 μm after 150 h annealing at 750 °C, which was reflected by the higher activation energy for grain growth (<em>Q</em>) of ∼1730 kJ/mol compared with other reported HEAs and conventional alloys. In addition, the resistance to grain growth and appearance time of abnormal grain growth (detected simultaneously with recrystallization completion at 950 °C) decreased with increasing temperature, which was explained by the variation of Zener effect. Considering the above results, the 750 °C/96 h annealed specimen with the homogeneous microstructure of micron-sized (∼1.13 μm) grains and abundant submicron-sized (∼0.40 μm) precipitates was selected and verified to possess a good combination of tensile and fatigue properties.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114563"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723694","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}