Science and Technology of Welding and Joining最新文献

{"title":"Frequency of cardioversions as an additional risk factor for stroke in atrial fibrillation - the FinCV-4 study.","authors":"Samuli Jaakkola, Tuomas O Kiviniemi, Jussi Jaakkola, Jussi-Pekka Pouru, Ilpo Nuotio, Tuija Vasankari, Juha E K Hartikainen, K E Juhani Airaksinen","doi":"10.1080/07853890.2022.2077430","DOIUrl":"10.1080/07853890.2022.2077430","url":null,"abstract":"<p><strong>Background: </strong>Patients with atrial fibrillation (AF) are selected for oral anticoagulation based on individual patient characteristics. There is little information on how clinical AF burden associates with the risk of ischaemic stroke or systemic embolism (SSE). The aim of this study was to explore the association of the frequency of cardioversions (CV) as a measure of clinical AF burden on the long-term SSE risk, with a focus on patients at intermediate stroke risk based on CHA₂DS₂-VASc score. For these patients, additional SSE risk stratification by assessing CV frequency may aid in the decision on whether to initiate oral anticoagulation.</p><p><strong>Methods: </strong>This retrospective analysis of FinCV Study from years 2003-2010 included 2074 patients who were not using any oral anticoagulation (long term or temporary) after CVs and undergoing a total of 6534 CVs for AF from emergency departments of three hospitals. Two study groups were formed: high CV frequency (mean interval between CVs ≤12 months and low frequency (>12 months).</p><p><strong>Results: </strong>A total of 107 SSEs occurred during a mean follow-up of 5.4 years. The event rates per 100 patient-years were 1.82 and 0.67 in high versus low CV frequency groups, respectively. After adjustment for CHA₂DS₂-VASc score, CV frequency independently predicted SSE (HR, 2.87 [95% CI, 1.47 to 5.64]; <i>p</i> = .002) at 3 years. Competing risk analysis also identified CV frequency (sHR, 2.70 [95% CI, 1.38-5.31]; <i>p</i> = .004) as an independent predictor for SSE. In patients with CHA₂DS₂-VASc score 1 and low CV frequency, the SSE risk was only 0.08 per 100 patient-years.</p><p><strong>Conclusions: </strong>Frequency of CVs for symptomatic AF episodes provides additional information on stroke risk in AF patients with CHA₂DS₂-VASc score 1.Key messagesThis retrospective study offers a unique opportunity to observe the natural course of AF patients with infrequent episodes of clinical arrhythmia when they were not using OAC (before introduction of CHA₂DS₂-VASc score).Stroke or systemic embolism rate was very low (0.08 per 100 patient-years) in patients with one CHA₂DS₂-VASc point who visited the emergency room for cardioversion less than once a year.Frequency of cardioversions can be used for additional risk stratification in patients at intermediate risk of stroke based on CHA₂DS₂-VASc score.</p>","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"18 1","pages":"1452-1458"},"PeriodicalIF":4.9,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9132398/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87699789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining the weldability window based on the interface morphologies formed during high-speed collision in magnetic pulse welding","authors":"Jishuai Li, R. N. Raoelison, T. Sapanathan, M. Rachik","doi":"10.1080/13621718.2022.2151733","DOIUrl":"https://doi.org/10.1080/13621718.2022.2151733","url":null,"abstract":"This paper aims to determine the weldability window in magnetic pulse welding, via computational and experimental analysis of the Al/Cu interface material response during the high-speed collision. The results reveal that the interface morphologies (straight, various type waves, vortices, cavities) arise from the differences in thermal and kinematic instabilities in between the aluminium side and copper side. The analysis of the percentage of straight and wavy morphologies based on the impact velocity versus impact angle allows to predict the weldability window which is potentially ‘L’ shaped with a convex shape tendency. Therefore, the proposed Eulerian model is robust enough to accurately predict the interface morphologies, and be used as tool to non-destructively depict the weldability window for an impact welding.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"259 - 267"},"PeriodicalIF":3.3,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42840410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural aging of heterogeneous arc-welded AA6061-AA7075 joints with nanocomposite filler","authors":"Narayanan Murali, Shiqi Zheng, Y. Chi, Xiaochun Li","doi":"10.1080/13621718.2022.2148066","DOIUrl":"https://doi.org/10.1080/13621718.2022.2148066","url":null,"abstract":"We report the dissimilar joining of aluminium alloys 6061 and 7075 using filler rods nano-treated with TiC nanoparticles. TiC enables the formation of a fine and equiaxial weld metal microstructure while preventing the formation of hot cracks. Dissimilar joints were also naturally aged, and their strength evolutions were tracked over 8 weeks and compared to a nano-treated, homogeneous AA7075 joint. Heterogeneous weld metals regained over 30 HV with a mix of MgZn2 and Mg2Si strengthening phases. Nano-treatment thus shows great promise, being able to facilitate the fusion welding of a traditionally difficult-to-weld system and enable a natural aging response between two artificially aged alloys.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"249 - 258"},"PeriodicalIF":3.3,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42479790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 dispersed carbon fibre network for reinforcing a C/C composite–TC4 alloy brazed joint","authors":"Zeyu Wang, Zhenjiang Ju, H. Butt, Guo-Hui Li, Tianmou Zhao, Zhao Mo, Manni Li, Zhijie Wang","doi":"10.1080/13621718.2022.2146323","DOIUrl":"https://doi.org/10.1080/13621718.2022.2146323","url":null,"abstract":"ABSTRACT In this work, a robust brazed joint of carbon fibre-reinforced carbon-based (C/C) composite and TC4 alloy was produced by utilising a slice of C/C as an interlayer. The C/C slice interlayer caused microstructural and mechanical property enhancement. During brazing, massive in situ formed carbon fibres broke away from the C/C slice bundles and were distributed in a three-dimensional interlocked network. These unique fibres consumed excessive Ti to inhibit the formation of excess brittle Ti–Cu compounds in the brazing seam. This reduced the coefficient of thermal expansion effectively, consequently relieving the high residual stress in the joint interface. The average shear strength of the joint brazed with the C/C slice interlayer reached 1.65 times higher than the directly brazed one.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"235 - 241"},"PeriodicalIF":3.3,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59817616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of delta-ferrite and its effect on impact toughness of GTAW weld metals in a 12 wt-% Cr steel","authors":"Dong-Sheng Wu, W. Tian, Kaiyuan Zhang, S. Lu","doi":"10.1080/13621718.2022.2148063","DOIUrl":"https://doi.org/10.1080/13621718.2022.2148063","url":null,"abstract":"This research focused on the formation of the δ-phase and the corresponding effect on the impact toughness in a GTAW weld metal of a 12%Cr F/M steel. Two kinds of δ-phase were identified: one located at the prior austenitic grain boundaries (PAGBs) (called δPAGB) and the other was in the inter-dendritic region (called δinter). The δinter implied that the peritectic transition that occurred at the final stage of solidification in the DSC test, was suppressed in the welding process. A preheating treatment at 95°C decreased optimally the δ-phase fraction and thereby decrease the ductile-brittle transition temperature (DBTT). However, excessive preheating at higher temperatures enhanced the fraction of the δinter by promoting the micro-segregation and thus increased the DBTT.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"242 - 248"},"PeriodicalIF":3.3,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46519970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of inclusions in novel cryogenic high-Mn austenitic steel weld metal with cerium addition","authors":"Jinshuai Zhang, Guangqiang Li, Honghong Wang, X. Wan, Mingfeng Hu, Yulong Cao","doi":"10.1080/13621718.2022.2146322","DOIUrl":"https://doi.org/10.1080/13621718.2022.2146322","url":null,"abstract":"Cerium (Ce) was effectively transitioned into the high-Mn austenitic steel weld metal under submerged arc welding by adding cerium dioxide and calcium silicon reducing agents into flux. The evolution behaviours of the composition, number density and size of inclusions in weld metal with different Ce contents were systematically investigated by thermodynamic calculation and experiments. The results show that the number density of inclusions increased and average size decreased with the increase of Ce content from 0 to 0.087 wt-%. Meanwhile, and the percentage of inclusions number with size less than 0.80 μm increased from 79.28% to 91.43%. The evolutionary process of inclusions was Al2O3 → Al11O18Ce → CeAlO3 → Ce2O3 → Ce2O2S with the increase of Ce content in the present weld metal. In particular, Ce-O-S-Al inclusion was extracted by in-situ sample preparation method, which proved its internal structure and evolution process. The complete formation model of Ce-Al-O-S system was also established.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"226 - 234"},"PeriodicalIF":3.3,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49338066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring coil geometry for secondary heating of substrate towards the development of induction heating-based wire additive manufacturing","authors":"Avadh Kishore Prasad, S. Kapil, S. Bag","doi":"10.1080/13621718.2022.2144800","DOIUrl":"https://doi.org/10.1080/13621718.2022.2144800","url":null,"abstract":"Induction heating (IH), a clean energy source, is potentially used to develop wire additive manufacturing (AM) system. The optimised parameters that simultaneously melt the mild steel wire and raise the substrate temperature is established. A fully coupled thermal-electromagnetic model of AM system is developed to perform numerical experiments on temperature development. The proposed hybrid helical-pancake coil with circular cross-section melt the metallic wire and raise the substrate temperature to 1490 K. The hybrid coil provides rapid heating to the wire (2819 K) and substrate together by enhancing magnetic field strength. The experiments using high-frequency IH system (550 A and 353 kHz) with a 3-turn helical coil is validated with model results for 2 mm mild steel wire.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"209 - 217"},"PeriodicalIF":3.3,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46735186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The most unforgettable character Prof. Tom Eagar","authors":"","doi":"10.1080/13621718.2022.2139939","DOIUrl":"https://doi.org/10.1080/13621718.2022.2139939","url":null,"abstract":"","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"172 - 172"},"PeriodicalIF":3.3,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49051253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 assisted longitudinal magnetic field on the microstructure and mechanical properties of ER2319 aluminium alloy parts fabricated by wire and arc additive manufacturing","authors":"Xujing Zhang, Wenyong Zhao, J. Long, Yanhong Wei","doi":"10.1080/13621718.2022.2145419","DOIUrl":"https://doi.org/10.1080/13621718.2022.2145419","url":null,"abstract":"The deposit morphology, microstructure, and mechanical properties of wire and arc additive manufacturing (WAAM) of ER2319 aluminium alloy with and without assisted longitudinal magnetic field (ALMF) were investigated comprehensively and comparatively in this study. The results showed that the ALMF improved the surface forming accuracy slightly, and effectively promoted the equiaxed transformation of grains. Simultaneously, the introduction of ALMF is beneficial to improving the morphology and distribution of the strengthening phase and reducing the tendency of intergranular corrosion caused by the segregation of Cu elements along the grain boundaries. Moreover, ALMF can remarkably reduce the generation rate of large pores, thereby effectively improving the tensile strength of the deposits and reducing the anisotropy of mechanical properties.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"218 - 225"},"PeriodicalIF":3.3,"publicationDate":"2022-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42250465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ta/Cu transition region in TC4/Inconel718 bimetallic structure fabricated by laser deposition manufacturing","authors":"Wang Chenyang, Xing Fei, Xu Guojian, Liu Xiangyu, Bian Hongyou","doi":"10.1080/13621718.2022.2143095","DOIUrl":"https://doi.org/10.1080/13621718.2022.2143095","url":null,"abstract":"The bimetallic structure formed by TC4 and Inconel718 has broad potential applications in aerospace. Based on the laser deposition manufacturing technique, a TC4/Inconel718 bimetallic structure was fabricated via the Ta/Cu transition layer. The test results indicated that a Ta/Cu transition region with a width of 475.0 μm was formed. The microstructure of the transition region changed from a reticular to a rod structure, and the corresponding phase compositions were β-Ta + Ti2Cu + TiCu and TiCu+γ-Cu + Cr2Ta. Owing to the formation of Ti–Cu and Cr–Ta phases in the transition region, the Vickers hardness reached 444.0 HV. The ultimate tensile strength was 280 MPa, and the fracture morphology presented a quasi-cleavage fracture, which occurred in the Ta/Cu transition region where Ti–Cu brittle phases exist.","PeriodicalId":21729,"journal":{"name":"Science and Technology of Welding and Joining","volume":"28 1","pages":"200 - 208"},"PeriodicalIF":3.3,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47702720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}