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1.
Reinforced ceramic dies for superplastic forming operations 总被引:2,自引:0,他引:2
Daniel G. Sanders 《Journal of Materials Engineering and Performance》2004,13(6):753-757
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. 相似文献
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Advances in fabricating superplastically formed and diffusion bonded components for aerospace structures 总被引:1,自引:0,他引:1
Larry D. Hefti 《Journal of Materials Engineering and Performance》2004,13(6):678-682
Superplastic forming and diffusion bonding (SPF/DB) production hardware is being fabricated today for aerospace applications.
Metal tooling is being used to bring the titanium sheets into contact so diffusion bonding can occur. However, due to material
sheet and tooling tolerances, good bond quality is difficult to achieve over large areas. A better method for achieving DB
is to use “stop-off” inside sealed sheets of titanium, which constitutes a pack, and then the pack is bonded using external
gas pressure. A good method for heating the pack for this process is to use induction heating. Components using “stop-off”
that were diffusion bonded first and then superplastically formed have shown much better bond quality than components that
were produced using matched metal tooling. This type of tooling has been successful at bonding small areas as long as the
exerted pressure is concentrated on the area where bonding is required. Finite element modeling is providing weight effect
solutions for titanium SPF/DB aerospace structures.
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. 相似文献
4.
《稀有金属材料与工程》2004,21(6):10-13
简要介绍了超塑性在压力加工方面以及相变超塑性在焊接方面的应用。重点介绍了超塑性成形和超塑性成形/扩散焊接技术在钛合金上的应用、超塑成形模具材料选择的原则、以及提高SPF部件性能的措施。 相似文献
5.
赵冰 《稀有金属材料与工程》2016,45(8):2189-2200
介绍了国内外在金属三维点阵结构制备方法的研究进展,及不同制备方法的特点,并进行了对比分析。提出了一种超塑成形/扩散连接工艺(SPF/DB)来制备金属三维点阵结构的方法,这种方法将点阵夹层结构看作三层或多层夹层结构,采用SPF/DB工艺方法在一个热循环中制备了金字塔型、四面体型、X型等典型的金属三维点阵结构,验证了工艺的可行性,为金属三维点阵结构的制备开辟了一条新的技术路径。对比分析了增材制造方法、塑性成形方法、SPF/DB等制备方法的特点和优点,对金属点阵结构技术的发展进行了展望。 相似文献
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F. Pitt M. Ramulu P. Labossiere S. Young 《Journal of Materials Engineering and Performance》2004,13(6):735-743
Ductility of three titanium alloys was evaluated after exposure to time and temperature conditions representative of superplastic
forming (SPF). Following exposure, flexural specimens were postprocessed to remove the α-case by one of three methods: no
material removed, the standard amount of material removed by chemical processing, or a reduced amount of material removed
also by chemical processing. Results include the evaluation of the specimens per ASTM E 290-97a and AMS-T 9046, springback
analysis, and prediction of minimum bend radius criteria for the three alloys from finite element method simulation. It was
found that results varied based on alloy and exposure temperature and the reduced postprocessing of titanium SPF parts produced
acceptable results under certain conditions.
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. 相似文献
8.
Peter N. Comley 《Journal of Materials Engineering and Performance》2004,13(6):660-664
Superplastic forming (SPF) of Ti-6Al-4V has traditionally been performed at 900 °C. Although SPF equipment and dies have been
developed to withstand this high temperature, their life is limited and maintenance is high. In addition, the formed sheets
need chemical milling after processing to remove a significant layer of alpha case, and parts require hand polishing due to
a rough die surface caused by high temperature oxidation. The recent development of a Ti-6Al-4V alloy with a grain size of
around 1 μm has led to the possibility of superplastic forming at a much lower temperature than regular Ti-6Al-4V. In addition,
the forming speed can be increased. This work looks at some of the SPF attributes of fine-grain titanium, in particular, the
optimum forming temperature, the thinning characteristics, alpha case formation, and forming speeds. The authors also address
manufacturing advantages, such as die life, equipment needs, and operator comfort. Some prototype and preproduction aircraft
components on Boeing airplanes are presented. The results show that the new fine-grain material could significantly lower
the cost of SPF Ti-6Al-4V part production for the aerospace industry.
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. 相似文献
9.
Larry D. Hefti 《Journal of Materials Engineering and Performance》2008,17(2):178-182
The Superplastically Formed and Diffusion Bonded (SPF/DB) titanium structure in production today for Boeing products, not
including engines, are all diffusion bonded using matched metal tooling and are all fabricated using the common 6Al-4V alloy.
The matched metal tooling concept presents a challenge in obtaining high-quality bonds over large areas due to tolerance build-up
in the tools and the titanium sheets. Boeing Commercial Airplanes (BCA) is currently advancing the state of the SPF/DB process
in several ways. One of these advances is using stop-off between the sheets and diffusion bonding the pack first and then
superplastically forming the stiffening features. This generates a component that is very well bonded in the required locations.
However, this process also has its challenges. One of these involves how to apply the stop-off material in the proper location
using the most cost effective process. Historically, silk screening has been used to define the required pattern for the stop-off
material. This process requires several pieces of equipment including a wash booth since the screen needs to be cleaned after
each part. A paper maskant and laser scribing process has been developed for defining the stop-off pattern. Also, because
diffusion bonding is performed first, when the component is superplastically formed, there is a tendency to form creases on
the surface of the part. Methods have been developed to eliminate these surface creases on the unformed surface. Another advance
in the SPF/DB process is in the titanium alloys being used for products. A fine grain 6Al-4V material has been developed that
bonds and forms at 775 °C. The use of this material will minimize wear on the tools and presses as well as significantly reducing
the amount of alpha case on the part surface.
This article was presented at the AeroMat Conference, International Symposium on Superplasticity and Superplastic Forming
(SPF) held in Baltimore, MD, June 25-28, 2007. 相似文献
10.
钛合金空心风扇叶片成形三维有限元分析 总被引:1,自引:0,他引:1
随着高旁路涡扇发动机在军用、民用飞机上的应用,采用超塑成形/扩散连接(SPF/DB)技术制造大尺寸钛合金宽弦风扇叶片已经成为涡扇发动机的一项关键制造技术.钛合金空心风扇叶片的成形过程包括3个阶段:扭转成形、热成形、超塑成形.在本研究中,为了分析空心风扇叶片的成形过程,建立了一个三维有限元模型,钛合金的变形行为符合Backofen方程.通过三维有限元模型,分析扭转速率、热成形模具下落速度、超塑成形目标应变速率、板材与模具之间的摩擦系数、芯板和面板的厚度比等参数对成形力的影响规律.研究表明,随着扭转速度、热成形模具的下落速度、目标应变速率、板材厚度比的提高,成形力将提高,而摩擦系数对成形力的影响很小. 相似文献
11.
Ti-6Al-4V (Ti-6-4) sheets of two different grain sizes were exposed to time and temperature conditions representative of superplastic
forming (SPF). The influence of SPF conditions on oxidation rates was evaluated in terms of weight gain, α-case depth, and
microhardness profile. Differences in the response are related to the difference in grain size between the two lots of Ti-6-4.
Fine grain Ti-6Al-4V exhibits faster oxygen diffusion in all three areas examined in this study, weight gain, α-case thickness,
and increased microhardness depth. The differences were found to be significant relative to diffusion analysis and processing
during manufacturing. Results from this work support reduced temperature SPF using fine grain material and the accompanying
benefits in manufacturing superplastic parts.
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. 相似文献
12.
Krajewski Paul E. Morales Arianna T. 《Journal of Materials Engineering and Performance》2004,13(6):700-709
Quick plastic forming (QPF) was developed as a high-volume, hot blow forming process for automobile components, enabling larger
volume applications than traditional superplastic forming (SPF). One critical aspect of the process is the tribological interaction
between the forming tool and the aluminum blank, as this impacts formability, surface quality, and tool durability. While
QPF has been successfully implemented for automobile components, many opportunities exist for improving the tribological condition
during the process, including the die coating or treatment, the lubricant, and the fundamental understanding of aluminum/iron
adhesion under QPF conditions (450 °C). This work reviews key tribological issues affecting QPF and identifies areas where
additional research is required.
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. 相似文献
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This experimental study investigates a post-Superplastic Forming (SPF) processing method with reduced material removal requirements
and its effect on high-cycle fatigue behavior. Comprehensive high-cycle fatigue experiments were conducted on three titanium
alloys in part to validate the proposed post process and in part to provide baseline properties for evaluating additional
materials. High-Cycle Fatigue results indicated that lower temperature superplastic forming conditions allow more efficient
use of titanium material. Manufacturing process designers needing to predict the best SPF conditions and establish design
allowables for titanium alloys may find the results of this research useful.
This article was presented at the AeroMat Conference, International Symposium on Superplasticity and Superplastic Forming
(SPF) held in Seattle, WA, June 6-9, 2005 相似文献
16.
Superplastic forming (SPF) of titanium 6Al-4V, with a standard grain size of about 8 μm, is typically performed between 900°
and 920°C. Verknaya Salda Metallurgical Production Association in Russia has developed a fine-grain version of the 6–4 alloy,
with a grain size of about 1 μm, which can be superplastically formed at around 775° C. Since this material diffusion bonds
to itself as well as other standard grain size titanium alloys at this temperature, super-plastically formed and diffusion
bonded (SPF/DB) hardware can be produced. There are several advantages to using this lower forming temperature, including
a smaller amount of alpha case developed on parts, longer press platen and heater life, and less oxidation of the tool surface.
This fine-grained 6–4 material is currently being used in the production of SPF and SPF/DB aerospace components due to these
advantages. 相似文献
17.
本文针对目前超塑成形与扩散连接组合工艺(SPF/DB)中普遍存在的模具气路设计复杂、时间—气压曲线难以控制等问题,提出了一种采用新型加压价质进行SPF/DB的新工艺。文中给出了气体发生剂的选取原则,对Al-Li合金在空气中的扩散连接提出了一整套工艺规范。文中所提出的工艺对Al-Li合金外的其它材料也同样具有实用价值。 相似文献
18.
研究了SPF/DB Ti-6Al-4V合金及其激光焊接接头静态拉伸性能和疲劳性能,并获得S-N曲线.通过观察组织特征和疲劳断口形貌,分析了激光焊接对SPF/DB Ti-6Al-4V合金疲劳性能的影响.结果表明,SPF/DB T-6Al-4V合金激光焊接接头的抗拉强度略低于母材抗拉强度,而疲劳强度明显低于母材疲劳强度,约为其抗拉强度的40%.SPF/DB Ti-6Al-4V合金组织为α+β等轴细晶组织,其焊接接头组织为含α,针状马氏体α'和少量β相的魏氏组织结构.焊接接头组织结构的不均匀性,以及组织的粗大化是导致激光焊接接头疲劳性能下降的重要原因.SPF/DB Ti-6Al-4V合金疲劳断裂为塑性断裂,其焊接接头疲劳断裂为准解理断裂,这显著降低激光焊接接头的疲劳性能.而焊接气孔等焊缝表层微小几何不连续缺陷的存在往往成为激光焊接接头疲劳断裂的裂纹源. 相似文献
19.
Peter Comley 《Journal of Materials Engineering and Performance》2007,16(2):150-154
Most parts made by superplastic forming (SPF) have been formed at an optimum strain rate. The rate is selected to give the
best SPF properties of the material. However, it has been proposed that multi-rate forming, where an initial high strain rate
is successively reduced as the part is strained, can be used to make high strain parts in a much shorter time than traditional
SPF forming. This paper examines the performance of fine grain Ti-6Al-4V alloy at very high initial strain rates, from 10–30
times faster than usual, with step reductions at prescribed levels of strain that still enables a total strain of over 2.1
(800%) to be achieved without degradation of the material. The paper also shows that the forming time to 100% deformation
can be reduced from 55 min to 9 min. This technique can be used by industry to enable faster flow times and lower production
costs of SPF 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. 相似文献