钛合金超塑性成形

本文从介绍金属材料超塑性成形的优缺点入手,列举了迄今世界上已证明具有超塑性特性的钛合金的牌号(成分)及其重要的超塑性特性指标,然后介绍了几项钛合金超塑性特性在生产中正在成功地应用的技术—胀形、成形和扩散连接以及超塑性等温锻造和等温锻造。     

块体非晶合金超塑性成形的研究进展

简述了块体非晶合金的研究现状及其超塑性成形技术,重点介绍了温度及应变速率对非晶合金超塑性的影响、块体非晶合金过冷液相区本构模型研究概况以及超塑性成形的应用,提出了块体非晶合金超塑性研究中仍需解决的问题。     

搅拌摩擦在超塑性材料焊接及成形方面的应用

大量的研究结果表明搅拌摩擦焊接是保证超塑性材料焊接后仍能保持高强度和高塑性的有效焊接方法。尤其是在高应变速度、低温和较低流动应力情况，采用搅拌摩擦成形（Friction Stir Process:FSP）技术来生产超塑性材料是相对简单且有效的方法。对搅拌摩擦在超塑性材料焊接和成形方面的进展做了简要的总结，包括材料、工艺参数及其影响因素等方面。     

大块非晶态合金成形技术研究现状

介绍了两种非晶态合金材料成型技术的研究状况,一是超塑性精密净成形,另一是近净铸造成形技术.对其适应性做了评述:认为超塑性成形要求的温度区间很窄,应变速率很低,限制了它的进一步应用;近净铸造成形技术在较大尺寸非品器件成形方面具有更大优势,但其理论和应用研究尚需深入.     

镁合金的成形技术及其应用研究

介绍了镁合金的铸造、塑性变形、超塑性成形等成形技术,以及镁合金在航空航天、汽车、电子产品等领域的应用,讨论了存在的问题和对前景展望。     

金属超塑性成形的应用概况

叙述金属超塑性成形的种类,实现细晶粒超塑性的必要条件。介绍超塑性成形工艺的应用现状。列出金属及合金的超塑特性。推荐超塑性成形用的模具材料。文末指出超塑性模锻工艺的优点。     

SPF／DB在空心叶片制造中的应用

主要介绍了超塑性成形和扩散连接（SPF／DB）技术在夹心结构空心叶片制造方面的应用，前、后缘以及局部形状设计要求，叶片的厚度分布，金相组织，机械特性和可行的工艺流程。     

镁合金的特点及其塑性加工技术研究进展

介绍了镁合金的性能特点及其在航天航空领域、汽车工业、3C产品中的应用前景,阐述了镁合金塑性加工现状及研究进展,分析了镁合金挤压、热冲、热锻、等温锻造、超塑性成形及剧塑性成形技术特点及工艺关键。     

H13钢锻模型腔超塑性成形工艺研究

本文主要叙述 H13钢摩托车曲拐头锻模采用超塑性成形工艺制模的有关问题.首先介绍了自己改造的超塑性成形压机的主要性能以及研制的超塑性成形 SL—2非玻璃质润滑保护剂的优异性能;同时对超塑性制模工艺中的主要问题包括工装结构设计、选材及工艺参数的选择等进行了详细论述,并探索出了不预处理型腔超塑性成形工艺。本研究中,采用超塑性成形工艺成形的曲拐头锻模寿命可达2万件以上,比现用的机械加工3Cr2 W8V 锻模寿命高3.5倍左右。当锻件产量大于5万件时,超塑性制模成本将低于机械加工制模成本.产量越大,成本越低,经济效益就越好。     

第2届钛合金结构成形技术交流会暨第7届超塑性学术研讨会在广西桂林召开

第二届钛合金结构成形技术交流会暨第七届超塑性学术研讨会于2006年5月26日至30日在桂林圆满结束。此次会议由北京航空制造工程研究所主办，中国航空一集团科技发展部、中国锻压学会超塑性专业分会、中国航空学会工艺专业分会协办，法国奥伯杜瓦公司独家赞助，是继2002年上海会议以来，又一次关于钛合金结构成形技术方面的全国性技术、学术交流会。本次会议共有来自航空、航天、兵器和船舶等国防工业部门以及高校等50多个单位的130多名代表出席了会议。与会代表主要围绕钛合金新结构设计与应用技术、SPF和SPF／DB技术及其模拟仿真、钛合金的热成形技术、管件成形技术、旋压成形技术、钛合金薄壁结构焊接技术、钛合金化铣和阳极氧化技术等专题进行了交流，并邀请了一些高校和研究院所的知名专家学者就相关主题做了学术与技术报告，充分展示了近年来我国在钛合金结构成形方面的科研、生产中的新进展，显示出钛合金结构成形技术在武器装备领域的良好应用前景。     

镍基合金超塑成形与扩散连接技术研究进展

本文对镍基合金超塑成形与扩散连接技术的研究概况及取得的研究成果进行了综述 ,并根据镍基合金在航空航天中的应用情况 ,对镍基合金超塑成形 /扩散连接 (SPF/DB)技术在航空航天工业中的应用进行了探讨与展望。     

纳米陶瓷超塑加工成形的研究进展

在对纳米陶瓷超塑性拉伸研究进行总结的基础上 ,综述了陶瓷超塑成形的研究进展情况。指出 :陶瓷材料由于其超塑特性 ,所以能够用各种现有的金属塑性成形方法来成形。最佳成形温度范围大约在 12 0 0℃～ 15 0 0℃之间 ,最佳晶粒平均直径为 10 0nm～ 2 0 0nm。     

A review of the numerical analysis of superplastic forming

This paper reviews the literature on the numerical simulation of superplastic forming (SPF). After introducing the phenomena of superplasticity and superplastic constitutive equations, non finite element analyses are reviewed. The finite element method of solution to SPF simulation is then examined within the context of the standard flow formulation. However non steady state SPF is not ideally suited to a standard flow formulation and an alternative, incremental flow formulation is discussed.     

一种超塑成形设备的控制与应用

超塑成形是制造难变形材料复杂零部件的一种精密成形技术,超塑成形设备通过温度加热和测控系统以及成形速度和压力控制系统,使特殊材料在温度和气压作用下发生超塑变形。     

Reinforced ceramic dies for superplastic forming operations

Ceramic dies have been developed to meet the need for a dimensionally stable tool, which can withstand the temperatures (425 to 950 °C) and high forming pressures (up to 7 MPa) that are required for superplastic forming (SPF), superplastic forming with diffusion bonding (SPF/DB), and hot sizing of metal parts. With the improvements that have been made to strengthen fused silica based ceramics, the performance of ceramic tools is slowly closing in on meeting the same forming complexity as corrosion-resistant steel (CRES) dies can achieve. Boeing has successfully superplastically formed jet engine wide chord fan blades using ceramic dies, and many production aircraft parts are being built with Boeing’s patented ceramic die technology. This paper was presented at the International Symposium on Superplasticity and Superplastic Forming, sponsored by the Manufacturing Critical Sector at the ASM International AeroMat 2004 Conference and Exposition, June 8–9, 2004, in Seattle WA. The symposium was organized by Daniel G. Sanders, The Boeing Company.     

大型双曲率非等厚TC4钛合金壁板整体SPF/DB成形工艺及优化

针对大型双曲率非等厚TC4钛合金壁板整体SPF/DB成形工艺进行了研究.由于零件尺寸超过1800 mm,型面复杂(双曲率,弦高为330 mm),壁厚分布不均匀,成形后出现了严重开裂(多于6处)、明显缩沟(深度大于1.1 mm)和不贴模等缺陷,且在成形后难于通过化铣精确控制壁厚分布,提出了预变形、化铣、扩散连接和超塑成形...     

On the model of solid state joint formation under superplastic forming conditions

The peculiarities of solid state joint (SSJ) formation under conditions of superplastic forming (SPF) were investigated for the titanium alloy VT6S (Ti-6Al-4V). The influence of annealing and SPF on the change of state of the alloy surface was considered. A significant role of grain boundary sliding (GBS) in the formation of both surface microrelief and SSJ was established. It was shown that SSJ formation under SPF conditions is primarily a deformation process. Corresponding schemes of the appearance of surface microrelief and SSJ formation are proposed.     

Effect of superplastic forming exposure on fatigue crack propagation behavior of Ti-6Al-4V alloy

The effect of superplastic forming (SPF) exposure on the ε (strain)-N (number of cycles to failure) fatigue and fatigue crack propagation (FCP) behaviors of Ti-6Al-4V (Ti64) alloy was examined at 298 and 473 K. To simulate the thermal exposure during superplastic forming process, the mill-annealed Ti64 alloy sheet was heated in the vacuum chamber with the pre-determined temperature profile. Notable microstructural change during the SPF exposure included the shape of transformed β phase from fine and round particles in the as-received specimen to coarse angular particles in the as-exposed specimen. The effective grain size tended to increase with the exposure, enhancing the slip reversibility and the resistance to FCP. However, the crack hindering effect by fine, particle-like β phase became weak with the exposure, offseting the beneficial effect associated with the increment of effective grain size. The effect of SPF exposure on ε-N fatigue and FCP behavior of mill-annealed Ti64 alloy was therefore marginal, excluding the effect of α-case (the oxygen-enriched phase) on the surface.     

Superplastic forming gas pressure of titanium alloy bellows

The complex superplastic forming (SPF) technology applying gas pressure and compressive axial load is an advanced forming method for titanium alloy bellows, whose forming process consists of the three main forming phases namely bulging, clamping and calibrating phase. The influence of forming gas pressure in various phases on the forming process was analyzed and the models of forming gas pressure for bellows were derived according to the thin shell theory and the plasticity deformation theory. Using the model values, taking a two-convolution DN250 Ti-6Al-4V titanium alloy bellows as an example, a series of superplastic forming tests were performed to evaluate the influence of the variation of forming gas pressure on the forming process. According to the experimental results these models were corrected to make the forming gas pressures prediction more accurate.     

The Effects of Stress State and Cavitation on Deformation Stability During Superplastic Forming

The current available models describing superplastic deformation do not account for a number of important characteristics, leading to the current limited predictive capabilities of deformation and failure. In this work, the effects of cavitation and stress state on deformation stability during superplastic forming are investigated using Finite Element simulations. The simulations are performed using constant strain rate forming and using a proposed optimization approach based on a multiscale failure criterion that accounts for stress state, geometrical necking, and microstructural evolution including grain growth and cavitation. The simulations are conducted for the superplastic copper-based alloy Coronze-638 and the superplastic aluminum alloy Al-5083 which are known to develop significant cavitation during deformation. The results clearly show the importance of accounting for microstructural evolution during superplastic forming, especially when the state of stress is biaxial. Furthermore, the results highlight the effectiveness of the proposed optimization technique in reducing the forming time and maintaining the integrity of the formed parts. This article was presented at the AeroMat Conference, International Symposium on Superplasticity and Superplastic Forming (SPF) held in Seattle, WA, June 6-9, 2005.