The aim of this study is to master the influence of the forging process on the micro structure and properties of TA15 flat billets,and to determine the appropriate forging process for the field.In this study,the effec...The aim of this study is to master the influence of the forging process on the micro structure and properties of TA15 flat billets,and to determine the appropriate forging process for the field.In this study,the effects of different forging deformation processes on the micro structure and mechanical properties of TA15 titanium alloy flat billets(80 mm×150 mm×1400 mm)were investigated.The billets underwent various heat treatments at 800-850℃for 1-4 h,and their resulting microstructures and mechanical properties were analyzed.The results showed that billets formed at a primary forging temperature(T_(1)),then air-cooled,and then subjected to a secondary forging temperature(T_(2))with rapid cooling,contained only 10%primaryα-phase,alongside abundant thin acicular phases.This micro structure exhibited high strength at both room and elevated temperatures,with comparable transverse and longitudinal strengths.These findings suggest that a two-step forging process—primary forging followed by air cooling,then secondary forging followed by rapid cooling—is ideal for manufacturing aircraft frame components.展开更多
Plasma arc cold hearth melting(PAM)technology represents a notable advancement in titanium metallurgy,as it effectively eliminates high-and low-density inclusions in titanium alloys.This study aims to explore the comp...Plasma arc cold hearth melting(PAM)technology represents a notable advancement in titanium metallurgy,as it effectively eliminates high-and low-density inclusions in titanium alloys.This study aims to explore the compositional homogeneity and longitudinal/transverse macrostructures of∅660 mm titanium alloy ingots produced via single-pass PAM.Further,the compositional uniformity of∅760 mm titanium alloy ingots fabricated through hybrid PAM and vacuum arc remelting(VAR)is examined.Thereafter,the mechanical properties of forged bars from PAM+VAR ingots are experimentally evaluated,revealing that the PAM ingots exhibit shallower melt pools and finer grain structures compared with the VAR ingots,although with inferior compositional uniformity and surface quality relative to triple VAR ingots.Overall,PAM+VAR effectively mitigates composition heterogeneity in single PAM ingots while satisfying forging requirements.展开更多
目的梳理过渡期护理的发展脉络,分析对比国内外过渡期护理的研究热点与前沿。方法通过中国期刊全文数据库和Web of ScienceTM核心合集检索2000-2019年发表的过渡期护理相关文献,采用CiteSpace软件构建科学知识图谱进行可视化分析。结果...目的梳理过渡期护理的发展脉络,分析对比国内外过渡期护理的研究热点与前沿。方法通过中国期刊全文数据库和Web of ScienceTM核心合集检索2000-2019年发表的过渡期护理相关文献,采用CiteSpace软件构建科学知识图谱进行可视化分析。结果共检出中、英文文献285篇、1179篇,年度刊载量均从2012年开始呈较明显的上升趋势,高产机构和作者相对分散,中文文献侧重生命质量等主观指标,体裁多为综述,而英文文献则聚焦于再入院率、病死率等更为客观的指标,且以干预性研究为主;中文的"微信"和英文的"姑息照护"为近年的突显词。结论国内过渡期护理发展相对滞后,发文机构及作者间合作有待加强;未来关于姑息照护和以微信为干预媒介的研究可能成为该领域的关注热点。展开更多
目的对比国内外翻转课堂在护理教育领域应用的研究热点,旨在为我国护理教育工作者进一步开展翻转课堂提供参考。方法应用CiteSpace软件对CNKI及万方数据库2015—2019年、Web of Science核心合集数据库2013—2019年收录的关于翻转课堂在...目的对比国内外翻转课堂在护理教育领域应用的研究热点,旨在为我国护理教育工作者进一步开展翻转课堂提供参考。方法应用CiteSpace软件对CNKI及万方数据库2015—2019年、Web of Science核心合集数据库2013—2019年收录的关于翻转课堂在护理教育中应用的文献进行可视化分析。结果筛选出中文文献135篇,英文文献114篇,发文量整体呈现逐年上升趋势,中文文献关键词网络密度不高,研究学者相对分散。结论中文文献主要以应用实践为主,应加强理论模式研究和本土化探索合作,促进翻转课堂在护理教育领域的深入发展。展开更多
基金funding received from the National Key R&D Program of China(No.2022YFB3705600)。
文摘The aim of this study is to master the influence of the forging process on the micro structure and properties of TA15 flat billets,and to determine the appropriate forging process for the field.In this study,the effects of different forging deformation processes on the micro structure and mechanical properties of TA15 titanium alloy flat billets(80 mm×150 mm×1400 mm)were investigated.The billets underwent various heat treatments at 800-850℃for 1-4 h,and their resulting microstructures and mechanical properties were analyzed.The results showed that billets formed at a primary forging temperature(T_(1)),then air-cooled,and then subjected to a secondary forging temperature(T_(2))with rapid cooling,contained only 10%primaryα-phase,alongside abundant thin acicular phases.This micro structure exhibited high strength at both room and elevated temperatures,with comparable transverse and longitudinal strengths.These findings suggest that a two-step forging process—primary forging followed by air cooling,then secondary forging followed by rapid cooling—is ideal for manufacturing aircraft frame components.
文摘Plasma arc cold hearth melting(PAM)technology represents a notable advancement in titanium metallurgy,as it effectively eliminates high-and low-density inclusions in titanium alloys.This study aims to explore the compositional homogeneity and longitudinal/transverse macrostructures of∅660 mm titanium alloy ingots produced via single-pass PAM.Further,the compositional uniformity of∅760 mm titanium alloy ingots fabricated through hybrid PAM and vacuum arc remelting(VAR)is examined.Thereafter,the mechanical properties of forged bars from PAM+VAR ingots are experimentally evaluated,revealing that the PAM ingots exhibit shallower melt pools and finer grain structures compared with the VAR ingots,although with inferior compositional uniformity and surface quality relative to triple VAR ingots.Overall,PAM+VAR effectively mitigates composition heterogeneity in single PAM ingots while satisfying forging requirements.
文摘目的梳理过渡期护理的发展脉络,分析对比国内外过渡期护理的研究热点与前沿。方法通过中国期刊全文数据库和Web of ScienceTM核心合集检索2000-2019年发表的过渡期护理相关文献,采用CiteSpace软件构建科学知识图谱进行可视化分析。结果共检出中、英文文献285篇、1179篇,年度刊载量均从2012年开始呈较明显的上升趋势,高产机构和作者相对分散,中文文献侧重生命质量等主观指标,体裁多为综述,而英文文献则聚焦于再入院率、病死率等更为客观的指标,且以干预性研究为主;中文的"微信"和英文的"姑息照护"为近年的突显词。结论国内过渡期护理发展相对滞后,发文机构及作者间合作有待加强;未来关于姑息照护和以微信为干预媒介的研究可能成为该领域的关注热点。
文摘目的对比国内外翻转课堂在护理教育领域应用的研究热点,旨在为我国护理教育工作者进一步开展翻转课堂提供参考。方法应用CiteSpace软件对CNKI及万方数据库2015—2019年、Web of Science核心合集数据库2013—2019年收录的关于翻转课堂在护理教育中应用的文献进行可视化分析。结果筛选出中文文献135篇,英文文献114篇,发文量整体呈现逐年上升趋势,中文文献关键词网络密度不高,研究学者相对分散。结论中文文献主要以应用实践为主,应加强理论模式研究和本土化探索合作,促进翻转课堂在护理教育领域的深入发展。
