Quasi-static tensile behavior of large-diameter thin-walled Ti-6Al-4V tubes at elevated temperature

来源 :Chinese Journal of Aeronautics | 被引量 : 0次 | 上传用户:l1otus
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
As promising light-weight and high-performance structure components, large-diameter thin-walled(LDTW) Ti–6Al–4V titanium alloy(TC4) bent tubes are needed most urgently in many industries such as aviation and aerospace. Warm bending may be a feasible way for manufacturing these components. Understanding their temperature and strain rate dependent tensile behavior is the foundation for formability improvement and warm bending design. In this paper, uniaxial tensile tests were conducted at elevated temperatures ranging from 298 K to 873 K at tensile velocities of 2, 10, 15 mm/min. The main results show that the tensile behavior of LDTW TC4 tubes is different from that of TC4 sheets. The typical elongation of TC4 tubes at room temperature is 10%lower than that of TC4 sheets. The flow stress of TC4 tubes decreases greatly by about 50% with the temperature rising to 873 K. At temperatures of 573–673 K, the hardening exponent is at its highest value, which means the deformation mechanism changes from twining to more dislocation movement by slipping. The fracture elongation of TC4 tubes fluctuates with increasing temperature,which is associated with changes in the deformation mechanism and with the blue brittleness. The fractography of TC4 tubes at various temperatures, especially at 673 K, shows that second phases and impurities significantly influence fracture elongation. By considering the characteristics of the tensile behavior and by properly choosing the die material, the warm bending for TC4 tubes can be achieved at temperatures of 723–823 K. As promising light-weight and high-performance structure components, large-diameter thin-walled (LDTW) Ti-6Al-4V titanium alloy (TC4) bent tubes are needed most urgently in many industries such as aviation and aerospace. a feasible way for manufacturing these components. Understanding their temperature and strain rate dependent tensile behavior is the foundation for formability improvement and warm bending design. In this paper, uniaxial tensile tests were conducted at elevated temperatures ranging from 298 K to 873 K at tensile velocities of 2, 10, 15 mm / min. The main results show that the tensile behavior of LDTW TC4 tubes is different from that of TC4 sheets. The typical elongation of TC4 tubes at room temperature is 10% lower than that of TC4 sheets. The flow stress of TC4 tubes decreases greatly by about 50% with the temperature rising to 873 K. At temperatures of 573-673 K, the hardening exponent is at its highest value, which means the deformation mechanis m changes from twining to more dislocation movement by slipping. The fracture elongation of TC4 tubes fluctuates with increasing temperature, which is associated with changes in the deformation mechanism and with the blue brittleness. The fractography of TC4 tubes at various temperatures, especially at 673 K , shows that the second phases and the more prominent influence fracture elongation. By considering the characteristics of the tensile behavior and by properly choosing the die material, the warm bending for TC4 tubes can be achieved at temperatures of 723-823 K.
其他文献
提到我国的花生,想必大家都会想到河南正阳花生,该地区的花生以“珍珠豆”型特色著称,不仅在国内湖南、广东、广西、山东等省市畅销,还远销至日本、韩国、东南亚等国家和地区
为了研究新型连续地月转移系统的动力学及能量需求,采用Lagrange方法,在系绳为刚性杆假设的前提下,同时忽略第三体引力、地球扁率和系绳轴向变形等扰动因素的影响,建立了驱动
高职院校的人才培养目标是培养“具有良好职业道德和内在素质,服务生产、建设、管理等一线应用型专业人才”。高等数学作为高职教育的重要基础课程,对人才目标培养的实现具有至关重要的作用。其中,数学建模有利于培养和提高高职学生的知识应用能力、信息技术应用能力、文献查询和创新能力。  一、高职院校数学建模现状  1.学生  随着近几年高校扩招,在一定程度上影响了生源质量。高职学生基础薄弱,知识体系不完善,进入
音乐教育作为我国教育领域的一部分,随着我国对教育事业的大力推进,也有了显著的发展,主要表现在对于高职高专开设了专门的音乐教学课程,但由于音乐教学存在一定的缺陷,所以
本文采用实证研究的方式探讨决策者背景特征对跨国并购绩效的影响机制。本文筛选出44家在2009-2012年发生重大并购案的上市公司。以经济心理学、行为经济学、管理学的相关理论及跨国并购理论为研究的理论基础,选取样本公司跨国并购前一年、跨国并购当年、跨国并购后第一年、跨国并购后第二年等四年的可以代表公司盈利能力、营运能力、成长能力和偿债能力的十二个财务指标,通过对其进行因子分析,提取出四个能够代表这四
互联网金融是一种新型的金融方式,在传统的互联网金融管理工作中,利用的管理模式是无法适合现代社会的发展需要,也无法合理解决互联网金融中存在的一些风险因素.所以,四川大
通过长期的教学实践和经验总结阐述了培养学生语感的几种重要途径,在教学中充分开展教、学互动,相辅相成,共同提高教学质量。 Through the long-term teaching practice and
近年来,流动性已成为政府部门和学术界关注的一个热点问题。但关于流动性的研究尚处于初级阶段,对其内涵的理解并不统一,对其表现、成因及影响的分析也不深入和系统,而对其度
2015年10月17日,由中国工艺美术协会、中国工艺美术学会和福建省惠安县人民政府联合主办的“心造天成—中国惠安南派雕刻艺术展”在中国国家博物馆开幕。全国人大常委会原副
为进一步提高广大书法爱好者的创作水平,使刊物成为读者的良师益友。《巾国书法·翰墨天下》自2014年创刊起,开设了“月选、季评、年赛”栏日。《征稿启事》发出后得到了广大书法爱好者的热切关注和大力支持,每个月编辑部都会收到来自全国各地的大量投稿。2014年岁尾,我们对全年的月选及季评入选作品进行了初步评选,遴选出28人进入年赛,每人提供新作两件进行年赛评选。年赛由《巾国书法》杂志社与巾国书法家协会考级