Materials Characterization最新文献

{"title":"Simultaneous enhancement of the strength and plasticity of Fe12Mn steel through modulating grain morphology","authors":"Tao Li ,&nbsp;Zhiqiang Wu ,&nbsp;Wei Liu ,&nbsp;Hui Liu ,&nbsp;Nan Tang ,&nbsp;Haijun Pan ,&nbsp;Zhihui Cai ,&nbsp;Jun Hu","doi":"10.1016/j.matchar.2024.114566","DOIUrl":"10.1016/j.matchar.2024.114566","url":null,"abstract":"<div><div>The relationship between grain morphology and tensile properties of Fe-<img>12Mn steel thermo-mechanically processed by rolling annealing and re-cold rolling processes was investigated. The results indicated that the re-cold rolling deformed the mostly austenite grain morphology from equiaxed to lamellar, and the steel exhibited a yield strength of 1295 MPa, tensile strength of 1518 MPa, and elongation of 18 %. Compared to the experimental steel without re-cold rolling processes, more than 300 MPa tensile strength was improved and elongation increased from 14 % to 18 %. The steel demonstrated remarkable enhancement in mechanical properties owing to the “multistage TRIP effect”, which referred to the sequential martensitic phase transformation of austenite with varying stability as the strain increased. The change in grain morphology reduced the rate of twin formation and increased the nucleation point of the martensitic phase transition, this also stabilized the retained austenite by increasing the hard phases surrounding the retained austenite, which had multistage stability. These factors contributed to the “multistage TRIP effect”, which could be sustained to higher strains and presented regular fluctuations in work-hardening rates</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114566"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747368","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":"Investigation of microstructure, mechanical performance, and corrosion resistance of thin-walled titanium welded pipe by annealing process","authors":"Jibing Chen ,&nbsp;Yanfeng Liu ,&nbsp;Qi Chen ,&nbsp;Zhixiong Xie","doi":"10.1016/j.matchar.2024.114579","DOIUrl":"10.1016/j.matchar.2024.114579","url":null,"abstract":"<div><div>Thin-wall titanium welded pipe has important applications in the fields of new energy vehicles, aerospace, and heat exchangers, the mechanical properties and corrosion resistance after high-frequency induction welding are rarely studied. To improve the comprehensive performance of thin-walled titanium welded pipe, a heat process and the performance optimization mechanism were studied in this paper. In addition, we systematically explored the influence of heat treatment conditions on the microstructure, mechanical performance, and dissolution behavior of the welded pipe through various methods, including tensile tests, immersion tests, and electrochemical tests. The results indicated that heat treatment primarily regulates the quantity and distribution of martensitic phases, acicular structures, and serrated structures in the welded joints, thereby impacting the mechanical performance of the welded pipe. By following high-temperature annealing at 800 °C for 0.5 h, with a heating rate of 5 °C/min, the acicular and serrated structures in the welded joints completely disappeared, forming an annealed equiaxed structure consistent with the base material. Subsequent furnace cooling reduced internal thermal stresses within the grains, resulting in relatively smooth grain boundaries, reduced small-sized grains, and a more uniform distribution of grain sizes, ultimately eliminating the residual stresses. Consequently, the welded pipe exhibited outstanding comprehensive performance, including ultimate tensile strength, Vickers hardness, and fracture elongation of 439.2 MPa, 178.3 HV, and 18 %, respectively. Notably, under room temperature, after immersion in a 3.5 % sodium chloride solution for 28 days, there was no significant change in the sample's mass. Therefore, the properties of thin-walled titanium welded pipe can be improved by annealing process, and it provides strong support and reliable evidence for its application in related fields.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114579"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747391","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 facilitated by stray-grain chains in a high-γ'-content nickel-based alloy K4002 produced via electron beam powder bed fusion","authors":"Yunting Li ,&nbsp;Maodong Kang ,&nbsp;Yang Zhou ,&nbsp;Yuantao Xu ,&nbsp;Huipeng Yu ,&nbsp;Yufei Pan ,&nbsp;Jun Wang ,&nbsp;Chengqi Zhang","doi":"10.1016/j.matchar.2024.114589","DOIUrl":"10.1016/j.matchar.2024.114589","url":null,"abstract":"<div><div>Cracking significantly hinders the development of additive manufactured high-γ’-content nickel-based alloys. This study investigates the microstructure and cracking behavior of a high-γ'-content nickel-based alloy K4002 produced via electron beam powder bed fusion (EBPBF). The results suggest that liquation cracking is the predominant cracking mechanism observed. Stray-grain chains were found to promote liquation cracking due to several factors: i) The presence of <em>high angle grain boundaries (HAGBs)</em> between the stray grains and adjacent columnar grains; ii) the <em>higher density of geometrically necessary dislocations (GND)</em> within stray grains; iii) <em>Cr</em>_<em>23</em><em>C</em>_<em>6</em> carbides, at the stray grain boundaries, hinder dislocation motion and promote strain accumulation; and iv) the formation of <em>low-melting-point regions</em> around the Cr₂₃C₆ within the stray grain chains. Furthermore, the origin of stray-grain chains was analyzed using the Rayleigh number and the columnar-to-equiaxed transition (CET) criterion, revealing that the stray-grain chains originate from the CET. As a result, through optimizing the solidification rate to inhibit CET, stray-grain chains were effectively eliminated, leading to a 55 % reduction in crack incidence. The findings in this work provide guidance for mitigating liquation cracking induced by stray-grain chains during additive manufacturing.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114589"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747389","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":"On the dislocation storage capacity of additively manufactured Hastelloy X: In situ synchrotron diffraction study","authors":"Kartik Prasad ,&nbsp;Atsushi Ito ,&nbsp;Shiro Torizuka","doi":"10.1016/j.matchar.2024.114573","DOIUrl":"10.1016/j.matchar.2024.114573","url":null,"abstract":"<div><div>Considering the results obtained from different types of synchrotron diffraction experiments, this research investigation presents deeper insights about the effects of heat treatment on characterization of microstructure and mechanical properties of laser powder bed fusion (L-PBF) processed Hastelloy X (HX). HX is a candidate material for variety of applications ranging from petroleum and chemical industries, high temperature gas cooled reactors and gas turbine engines. L-PBF processed samples of HX were subjected to three aging treatments at 650 °C, 760 °C and 870 °C after solutionizing them at 1175 °C. Examination of Debye-Scherrer rings and orientation imaging maps (OIM) of electron back scattered diffraction (EBSD) experiments revealed the randomization of grains in heat treated microstructures of HX. Synchrotron diffraction patterns and transmission electron microscopy observations confirmed the presence of laves phase and carbides (M₆C and M₂₃C₆) in as-built HX (AB-HX). Increase in precipitation of M₂₃C₆ carbides with increase in aging treatment from 650 °C to 870 °C was revealed by line profiles of synchrotron diffraction patterns and EBSD phase maps. Tensile deformation behavior in four different metallurgical conditions of HX viz. AB-HX, solution treated (ST), solution treated and aged conditions was characterized by evaluating the evolving dislocation density carrying out in situ synchrotron diffraction experiments. The diffraction data corresponding to the first six {hkl} reflections were considered for evaluating the dislocation density using modified Warren-Averback methodology. Analysis of work hardening behavior, as probed by dislocation density measurements, indicated increase in dislocation storage capacity with increase in aging treatment from 650 °C to 870 °C. Variations in tensile properties were analyzed in light of the dislocation density measurements and EBSD results to gain more insight into the deformation mechanisms operating in different heat-treated conditions.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114573"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747392","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":"Twin-twin interaction behavior in tensile-deformed austenitic manganese steel","authors":"Linnan Dong ,&nbsp;Zhimin Ding ,&nbsp;Bo Liang ,&nbsp;Qiaomei Huang ,&nbsp;Rujin Tian","doi":"10.1016/j.matchar.2024.114582","DOIUrl":"10.1016/j.matchar.2024.114582","url":null,"abstract":"<div><div>Electron back scatter diffraction instrument and high-resolution transmission electron microscope were used to observe and characterize the twin-twin interaction behavior in tensile-deformed 120Mn13 steel at the atomic scale. Here the whole twin-twin interaction behavior was divided into three processes and the deformation mechanisms of each process were revealed, including the interaction between the incident twin and the coherent twin boundary of the barrier twin, which can lead to a twinning or detwinning process of the barrier twin, the trigger formation of secondary twins and the formation of second order twins in the intersection region. Based on the Thomson tetrahedron, the dislocation movements in different twin-twin interaction processes were systematically described, and the possibility of dislocation reactions were discussed in energy. The interaction mechanism of the microscopic zero-stain twin (MZST) was proposed for the first time, and its differences from the classical twin-twin interaction mechanism were expounded. Present work further enriches the twin-twin interaction behavior in face centered cubic metallic materials. It can also guide the in-depth understanding of the classical twin-twin interaction behaviors and be used to explain the formation of classical secondary and second order twins.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114582"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747390","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":"Ex-situ observation of ferrite grain growth behavior in a welded 9Cr-1Mo-V-Nb steel during aging at 740 °C","authors":"Katsuhiro Sato ,&nbsp;Masatoshi Mitsuhara ,&nbsp;Akihiro Shin ,&nbsp;Yoshiki Shioda ,&nbsp;Kyohei Nomura ,&nbsp;Keiji Kubushiro ,&nbsp;Noriko Saito ,&nbsp;Hideharu Nakashima","doi":"10.1016/j.matchar.2024.114584","DOIUrl":"10.1016/j.matchar.2024.114584","url":null,"abstract":"<div><div>It has recently been reported that ferrite grains coarsened to several hundred micrometers were occasionally observed in long-term serviced 9Cr-1Mo-V-Nb steel welds. To clarify the factors that cause ferrite grain growth in martensite during high-temperature exposure, alternating aging heat treatment and observation of the same field of view was performed using a welded 9Cr-1Mo-V-Nb steel. Such ex-situ observations revealed that the rapid grain growth of ferrite by consuming martensite occurred in the weld metal during aging at 740 °C. In the test material used in this study, some δ-ferrite grains were observed in the weld metal near the fusion line. In the region where δ-ferrite grains were observed, the concentrations of austenite-forming elements such as Mn and Ni were locally decreased in the matrix due to dilution by the base metal, promoting δ-ferrite retention after welding. Ex-situ observation indicated that no significant grain growth of δ-ferrite occurred during aging. Therefore, it was suggested that a new ferrite grain formation followed by rapid grain growth consuming martensite occurred during aging. The elastic strain energy density of the dislocations <em>P</em>^M_dis and the interfacial energy density <em>P</em>^M_surf in martensite can affect the driving force for ferrite grain growth by consuming martensite. Based on the evaluation results for <em>P</em>^M_dis and <em>P</em>^M_surf after 500 h of aging, <em>P</em>^M_surf was considered to be the main driving force for ferrite grain growth. Although the ferrite-formation process could not be directly observed, it is possible that ferrite was formed by the recrystallization of martensite through the bulging mechanism.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114584"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747385","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":"Microstructure and ablation resistance of C/C-HfC-SiC composites prepared by RMI with different powder particle sizes","authors":"Zhiqiang Liu,&nbsp;Yifan Sun,&nbsp;Shubo Zhang,&nbsp;Yawen Wang,&nbsp;Luncheng Tang,&nbsp;Tian Li,&nbsp;Qiangang Fu,&nbsp;Yujun Jia","doi":"10.1016/j.matchar.2024.114577","DOIUrl":"10.1016/j.matchar.2024.114577","url":null,"abstract":"<div><div>To improve the ablation and scouring resistance of C/C composites, powder with particle sizes of 0.5–1 μm, 1–3 μm and 10–20 μm were used as infiltration powder to prepare C/C-HfC-SiC composites, named HSV-0.5-1, HSV-1-3 and HSV-10-20, respectively. Results show that the agglomeration of the powder makes it difficult to form a uniform and dense ceramic layer on the sample surface. The content of HfC ceramics increases with the particle size of the initial powder. In addition, the grain size of HfC first increases and then becomes irregularly spherical as the initial powder particle size increases. After ablation for 40s, HSV-1-3 shows the best resistance to ablation due to the mixed crystal form of flakes and spheres that form a denser oxide film in the center of the ablation. In three subsequent room-temperature airflow scour tests, the oxide film of HSV-1-3 and HSV-10-20 were damaged in the sample surface. After following ablation for 40 s, HSV-10-20 showed good ablation resistance with the linear ablation of −0.75 μm/s. The reason is the high HfC content and dense ceramic layer contribute to the formation of a continuous and complete oxide layer that prevents oxygen diffusion during ablation. This work provides guidance on the use of particle size in the RMI.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114577"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747367","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 ball milling on densification and alloying in SiCp/Al powder metallurgy processes","authors":"X.M. Feng ,&nbsp;J.F. Zhang ,&nbsp;D. Wang ,&nbsp;B. Deng ,&nbsp;J. Wang ,&nbsp;B.L. Xiao ,&nbsp;Z.Y. Ma","doi":"10.1016/j.matchar.2024.114583","DOIUrl":"10.1016/j.matchar.2024.114583","url":null,"abstract":"<div><div>In this study, unprocessed raw Al, Cu, Mg powders, and SiC particles were mixed and subjected to high-energy ball milling (HEBM) to mitigate the negative effects of the oxide film on the quality of the pressureless sintering billets. Comparative experiments including pores and intermetallics examination were performed on both the mixed and HEBM powders across various preparation stages, including cold isostatic pressing, sintering, and hot extrusion of the 15vol.%SiC/Al-Cu-Mg. The pore structure and degree of alloying were analyzed using X-ray synchrotron radiation tomography. The results indicate that the brief HEBM process led to excellent mechanical properties in aluminum matrix composites after pressureless sintering and hot extrusion. The composites using ball-milled powder was relatively denser and complete alloying after sintering and extrusion, resulting in a density of up to 0.995 and a uniform distribution of Cu elements. The HEBM SiCp/Al had a tensile strength of 573 MPa and a fracture strain of 5.1 % which were higher than that of the mixed SiCp/Al. The results indicate that diffusion of alloy elements such as Cu was hindered by the interfaces between powders, led to Cu segregation and lower density of only 0.982 even after extrusion. Therefore, the composites using mixed powder had a lower tensile strength of 483 MPa and a fracture strain of 3.5 %. The study concluded that reducing the number and types of inter-particle interfaces could enhance the alloying and pore bridging processes.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114583"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747387","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":"Enhanced ultra-high temperature creep resistance originating from preferred microstructures of W-Re-HfC alloys","authors":"Shuai Ma ,&nbsp;Di Dong ,&nbsp;Mengyao Zhang ,&nbsp;Ye Gao ,&nbsp;Zhuangzhi Wu ,&nbsp;Dezhi Wang","doi":"10.1016/j.matchar.2024.114585","DOIUrl":"10.1016/j.matchar.2024.114585","url":null,"abstract":"<div><div>W-Re-HfC alloys have been extensively applied in the field of high-temperature structural parts. To ensure high temperature reliability, it is essential to enhance creep resistance ability. In this study, the microstructures of forged W-Re-HfC alloys were adjusted using different heat treatment processes. The corresponding tensile creep properties were also measured at 2000 °C with 40 MPa. Furthermore, a possible creep fracture mechanism was also explored. The forged W-Re-HfC sample annealed for 2 h exhibited the best creep performances with a steady-state creep rate of 3.28 × 10⁻⁶ and a creep life of 5.6 h. Generally, a larger grain size indicates a lower steady-state creep rate; however, the precipitation of carbides at the grain boundaries (GBs) deteriorates the bonding strength of interfaces, thus reversing the former trend. The dominant creep mechanism is diffusion creep, in which the voids nucleate perpendicular to the GBs, grow and connect into cracks, ultimately leading to fractures.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114585"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747388","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":"In-situ TEM study on the precipitation behavior of an Al-Mn-Mg-Sc-Zr alloy formed by SLM","authors":"Wenhao Li ,&nbsp;Pucun Bai ,&nbsp;Xiaoming Cui ,&nbsp;Xueping Zhao ,&nbsp;Shaobo Liang ,&nbsp;Jianlin An ,&nbsp;Yinjun Tian","doi":"10.1016/j.matchar.2024.114578","DOIUrl":"10.1016/j.matchar.2024.114578","url":null,"abstract":"<div><div>In this study, an Al-Mn-Mg-Sc-Zr alloy was prepared using the selective laser melting (SLM) technique, and the precipitation behavior during heating was characterized by In-situ transmission electronic microscopy (TEM). The results show that the microstructure of the deposited alloy is mainly composed of columnar crystals in the molten pool and equiaxed crystals at the bottom edge of the molten pool. Al₆Mn was identified as the major phase within the deposited alloy, in which Al₆Mn showed rod-shaped and particulate behavior distributed along the grain boundary of columnar crystal and equiaxed crystal. A detailed characterization of the precipitation behavior was conducted using in-situ TEM at various temperatures. At 250 °C, it was observed that the dislocation density decreased with heating time, showing no precipitation behavior, indicating good thermal stability of the alloy at this temperature. After the temperature was raised from 250 °C to 425 °C, a large number of fine and dispersed needle-rod secondary Al₆Mn phases were precipitated in the inner and bottom of the molten pool. With the increase in heating time, the size of the needle-rod secondary Al₆Mn phase increased, and no Al₃Sc precipitates were observed. However, the precipitation of Al₃Sc was found by ex-situ TEM. Thermodynamic properties of Al₃Sc and Al₆Mn were calculated by first principles. It is found that the free energy of Al₆Mn is lower than that of Al₃Sc in the temperature range of 85 to 800 K, which indicates that Al₃Sc has better thermodynamic stability than Al₆Mn.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114578"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757454","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}