共查询到18条相似文献,搜索用时 125 毫秒
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蠕变时效成形技术是为实现大型整体壁板构件高性能与精确成形协同制造而发展起来的一种新型钣金成形方法.分析了大型整体壁板构件的特点和蠕变时效成形技术的原理,从蠕变时效材料本构建模、模具型面回弹补偿和模具设计3个关键方面重点阐述了蠕变时效成形技术的研究进展,并且从材料本构向构件本构发展、蠕变成形向塑变与蠕变复合成形发展和简单热力能场向多级复合能场时效成形发展3个研究热点阐述了该技术进一步发展面临的挑战. 相似文献
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为研究2219铝合金在蠕变时效成形过程中,不同应力状态(拉/压)对其蠕变行为的影响规律,采用室温拉伸的方法研究了165~185℃内单轴拉/压2219铝合金力学性能的变化。结果表明:最佳蠕变时效时间为11 h;在相同的时效制度下,拉/压应力蠕变变形量均随着温度的升高而增加,拉应力的蠕变变形量始终大于压应力的蠕变变形量;无论是拉/压应力蠕变时效还是无应力常规时效,其时效后的性能均随着温度的升高而降低,然而,拉应力时效后性能的下降幅度最为明显;最后,在时效温度为165℃时,不同应力状态下的各项性能指标均表现为最佳。 相似文献
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先进航空板材成形技术应用现状与发展趋势 总被引:3,自引:0,他引:3
板材成形技术是武器装备发展中至关重要的技术之一,是一个国家军事技术能力和科技水平的重要组成部分。本文综合论述了以超塑成形/扩散连接技术、喷丸和蠕变时效成形技术、柔性多点模具蒙皮拉形技术和旋压成形技术等为代表的先进航空板材成形技术的应用现状,总结和提出了航空板材成形技术的发展趋势和重点。 相似文献
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大型机翼整体壁板时效成形技术 总被引:5,自引:0,他引:5
分析了单级时效、双/多级时效、振动时效以及应力位向效应等工艺措施和因素对铝合金机翼整体壁板材料时效成形特性的影响,得到以下结论:应采用双/多级时效处理,以提高成形后壁板材料的综合性能;应采用振动时效应力松弛,以加速应力松弛,降低回弹,并提高成形后壁板材料的抗疲劳性能;对时效过程中存在应力位向效应的铝合金,应设计合适的时间温度曲线与加载曲线,以避免壁板材料因应力位向效应产生各向异性,导致材料屈服强度降低。提出了大型机翼整体壁板时效成形的工艺流程,给出了成形过程中热压罐内的温度时间曲线和气压时间曲线;提出了成形工装的模块化、标准化与柔性化设计以及解决壁板时效成形回弹问题的有限元方法,并对中国研究发展大型机翼整体壁板时效成形技术提出了建议。 相似文献
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飞机大型蒙皮制造技术现状分析 总被引:1,自引:1,他引:0
大型蒙皮是大型飞机的外表主要大型薄壁零件,飞机大型蒙皮制造是大型飞机制造的关键技术之一。重点介绍了喷丸成形和蠕变时效成形两种大型蒙皮制造技术的特点、国内外发展现状以及其中的关键技术。为了提高我国大型蒙皮技术制造水平,必须加大设备和关键技术方面的投入,同时也要对激光钣金技术予以必要的关注。 相似文献
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Huang Lin Wan Min Chi Cailou Ji Xiusheng 《中国航空学报》2007,20(6):564-569
The age forming technology, characterized by huge spring-backs, has been developed to manufacture large integral wing-skin panel parts, which necessitates devising a method of predicting spring-backs. A 7B04-T7451 aluminum alloy creep test in tension is accomplished at 155 ℃, and the creep curves are obtained. The material constants of the mechanism-based creep constitutive equations are determined through experiments. The age forming process and the spring-backs of 7B04 aluminum alloy plates are analyzed using the commercial finite element software ABAQUS. The effects of plate thickness and forming time on spring-backs are researched. The spring-backs decrease with the increase of plate thickness and forming time. The test results verify the reliability of the finite element method (FEM) analysis. 相似文献
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《中国航空学报》2023,36(5):566-581
Non-isothermal Creep Age Forming (CAF), including loading, heating, holding, cooling and springback stages, is an advanced forming technique for manufacturing high performance large integral panels at short production period and low cost. However, the creep deformation and aging precipitation during heating stage is often neglected in experiments and modeling, leading to low forming precision. To achieve shape forming and property tailoring simultaneously, a deep understanding of the non-isothermal creep aging behavior and the establishment of predictive models are urgently required. A new five-stage creep feature of Al-Cu-Li alloy during the non-isothermal creep aging is observed. The microstructural interactions between the dislocations, solute atoms, Guinier Preston zones (GP zones) and T1 precipitates are found to dominate the five-stage creep aging behavior. The physical-based model considering temperature evolution history is established to describe the five-stage creep feature. The springback and yield strength of non-isothermal creep age formed plates with different thicknesses are predicted and compared by non-isothermal CAF experiments and corresponding simulations. The CAF experiments show that the springback and yield strength of the non-isothermal creep age formed plate are 62.1% and 506 MPa, respectively. Simulation results are in good agreement with experimental results. The proposed model broadens the application of traditional CAF models that mainly focus on isothermal conditions. 相似文献
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大型整体壁板成形技术 总被引:25,自引:4,他引:21
大型整体壁板是现代先进民用飞机的重要结构件,大型整体壁板成形技术是整机研制过程中所必须要解决的重大关键技术。从大型整体壁板的结构特点出发,介绍了整体壁板的结构形式和分类,重点阐述了整体带筋壁板喷丸成形技术和时效成形技术的国外研究应用进展及发展趋势,分析了国内现有整体壁板成形技术的基础和存在问题,特别介绍了国内在ARJ21新支线飞机研制中所取得的最新进展。最后针对中国大飞机研制的紧迫需求,提出了尽快开展大飞机机翼和机身整体壁板成形技术研究的建议和对策。 相似文献
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《中国航空学报》2016,(5):1445-1454
The initial temper of the material may directly affect the whole creep age forming(CAF)process. In terms of creep deformation and stress relaxation, using the constant-stress creep aging and constant-strain stress relaxation aging tests, the relationship between initial temper and CAF formability is investigated for an Al-Zn-Mg-Cu alloy at 165 °C for 18 h. Three tempers are selected as the initial tempers in CAF, viz., solution, retrogression and re-solution. The CAF formability of this alloy with initial temper of retrogression is the best, and the creep strain of the retrogression tempered specimen after creep aging of 18 h is about 1.21 and 1.34 times than that of the solution and the re-solution tempered specimens, respectively. The calculated stress exponents of this alloy with three initial tempers range from 7.3 to 9.5, indicating that the CAF of this alloy is mainly controlled by the dislocation creep. The various formability for three initial tempers are attributed to different inhibitions of the transgranular precipitates on the dislocation movement. For the retrogression temper, the initial fine and uniformly distributed precipitates are seriously coarsened after6 h of CAF, which minimally inhibit the dislocation movement. While, for the re-solution temper,the fine precipitates are re-precipitated in the matrix of the alloy, which observably hinder the dislocation movement and lead to the worst formability. 相似文献
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Fangpu LYU Chunhui LIU Peipei MA Jianshi YANG Longhui CHEN Lihua ZHAN Minghui HUANG 《中国航空学报》2023,36(7):518-530
The improvement of post-form properties without compromising creep formability has been a critical issue in creep age forming of aluminum alloy component. A pretreatment process incorporating artificial pre-aging at 165 °C for 6 h/12 h/24 h followed by pre-strain(3%–9%)has been developed. This method not only evidently improves the strength but also accelerates the creep deformation during creep aging of an Al-Cu alloy. A strength increase of 50 MPa with a slight decrease of ductility relative t... 相似文献
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Advances and challenges on springback control for creep age forming of aluminum alloy 总被引:1,自引:1,他引:0
Creep age forming(CAF) is an advanced forming technology that combines creep deformation and age hardening processes. When compared with the conventional forming technologies including roll bending and shot-peen forming, CAF has many advantages of low residual stress,excellent dimensional stability, good service performance and short production cycle. It is an optimal technique for precise manufacturing for shape and properties of large-scale complicated thinwalled components of light-weight and... 相似文献
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为了研究不同预变形量对铝合金蠕变行为及力学性能的影响规律。以2219铝合金为研究对象,在温度为175℃,180 MPa应力条件下,研究0~8%的预变形量对2219铝合金蠕变行为及力学性能的影响。结果表明:预变形处理的引入,材料的蠕变变形量和力学性能大幅度增加。当预变形处理量为1%时,其蠕变变形量较未处理时试样蠕变变形量增加了118%。而随着预变形量的继续增加,试样的的力学性能呈现快速下降的变化趋势。综合考虑蠕变变形量与力学性能时,最利于构件的蠕变时效成形的2219铝合金的预变形处理量为3%。 相似文献