基于拉伸试验和冲击液压胀形技术,研究了不同退火工艺对H65黄铜管力学性能和成形性能的影响。首先,基于拉伸试验分析了不同退火工艺参数下管材的力学性能,结果表明,随着退火温度的升高,强度和硬度下降,塑性上升,保温时间对材料力学性能

Liquid impact forming (LIF) is a new composite forming technology based on tube hydroforming (THF) technology, which changes the volume of die cavity through impact load and rapidly generates internal pressure to realize tube forming. It does not need external pressure supply source, and it is low cost and high efficiency. In order to study the forming characteristics of the natural bulging area of thin-walled metal tube under different model side lengths and different closing velocities, the change of the cavity volume of thin-walled metal tube under impact hydraulic bulging was first analyzed theoretically, and a mathematical model of internal pressure was established. Then the effects of different loading parameters on the internal pressure, bulging height and wall thickness distribution in the natural bulging area of thin-walled metal tube were studied. Finally, through the comparison of finite element simulation analysis and experiment, it was found that the deviation between the experimental results and the numerical simulation was within 6%, which verified the accuracy and reliability of LIF. It also provides a certain theoretical research and application basis for the development of LIF of metal thin-walled tube. © 2023 This work is made available under the terms of the Creative Commons Attribution 4.0 International license,.

The contact state of a seamless internal threaded copper tube and an aluminium foil fin not only affects the heat transfer efficiency of a tube–fin heat exchanger but also seriously affects its service life. In this study, hydraulic expansion technology was used to connect the copper tube with an internal thread with a 7 mm diameter to the fin of the heat exchanger. The influence of the expansion pressure and pressure holding time on the contact state was analysed through experiments and finite element simulation, and the variation law of the two on the contact state was obtained. The contact state was characterised by the contact gap and contact area. In order to obtain the specific contact area value, a new method of measuring the contact area was developed to reveal the variation in contact area between the copper tube and the fin after expansion. The results show that the contact gap decreases with an increase in expansion pressure, while the pressure holding time remains the same. The contact area increases with an increase in expansion pressure, and the rate of increase slows. When the expansion pressure is 18 MPa, the average contact gap is approximately 0.018 mm. When the expansion pressure reaches 16 MPa, the contact area ratio is 91.0%. When the expansion pressure increases to 18 MPa, the contact area ratio only increases by approximately 0.6%. Compared with the influence of the expansion pressure on the increase in contact area, the influence of the pressure holding time on the contact area is lower. © 2023 by the authors.

管材液压胀形（Tube Hydroforming）是实现零件结构轻量化、响应节能减排与可持续发展政策的先进塑性成形技术。其产品在保证高质量、高精度的同时,又兼具质量轻、强度高的优点,但液压胀形技术必须依赖高性能专用外部供压源,设备成本较高,同时加压、卸压周期较长影响了成形效率。冲击液压胀形（Liquid Impact Forming）是在液压胀形和冲压成形基础上发展起来的一种先进制造技术。该技术既保留了液压胀形的优点,又提高了成形效率,具有广阔的应用前景和研究价值。同时热处理工艺对材料的力学性能、成形性能及组织影响密切,因此本文以H65黄铜和6061铝合金管材为对象,基于冲击液压胀形技术研究了热处理工艺对其性能与组织的影响,希望为冲击液压胀形技术的研究提供有益参考。通过室温拉伸试验,测试了不同热处理工艺下H65黄铜和6061铝合金管材的力学性能,分析总结了管材力学性能参数随热处理工艺参数的变化规律;基于幂指数硬化模型建立了不同热处理工艺下H65黄铜和6061铝合金管材的塑性本构模型;退火温度为450℃、保温时间为60min时,H65黄铜管具有较小的屈强比和较大的应变硬化指数,更有益于材料的塑性变形,伸长率达到76.7%;热处理温度为550℃、保温时间为120min、冷却方式为空冷时,6061铝合金管具有较大的应变硬化指数,较小的屈强比,力学性能较佳,伸长率为26.1%。基于冲击液压胀形技术,完成了热处理态H65黄铜管和6061铝合金管的胀形试验,采集了不同热处理态成形件的冲击液压成形参数,总结了不同热处理工艺下成形件自然胀形区胀形高度、壁厚分布等胀形性能变化规律以及合模区胀形高度、圆角半径、壁厚分布等填充性能变化规律;退火温度为450℃、保温时间为60min时,H65黄铜成形件具有较佳的成形性能,自然胀形区胀形高度达到55.82mm,提高了约47%,且壁厚分布较为均匀;综合考虑成本、效率等因素,热处理温度为550℃、保温时间为120min、冷却方式为空冷是6061铝合金管材较为合理的热处理工艺,其自然胀形区胀形高度为46.26mm,提高了约22%。采用光学显微镜和扫描电镜的材料分析测试方法,分析了H65黄铜和6061铝合金冲击液压成形件典型部位微观组织及宏微观断口形貌。随着温度升高,材料初始组织的晶粒尺寸细化,成形件断口表面韧窝数量和深度增大,不同保温时间下试样组织变化不明显;由于塑性变形,各取样位置的晶粒发生不同程度的破碎、细化,自然胀形区试样的晶粒有沿塑性变形方向被拉长的趋势,晶粒具有较为明显的取向。

基于结构轻量化和一体化的管材液压胀形技术（Tube Hydroforming）如今正广泛应用于各个领域,该技术是以管材为毛坯,在液体压力和轴向载荷的联合作用下,将管材胀形为所需形状,但因其必须依赖高压液压源和相应的控制系统,存在制造成本较高、工作效率不足等缺点。冲击液压胀形（Liquid Impact Forming）是在冲击载荷和液压力联合作用下的管材胀形新技术,通过冲击载荷改变管材型腔体积,从而快速提高液压力,该技术不需要高压液压源,成形效率较高,具备一定的研究价值。目前许多学者对冲击液压胀形下管材合模区的研究取得了一定的成果,但缺乏冲击液压胀形下管材自然胀形区的研究,因此本文基于冲击液压胀形下管材自然胀形区的成形特性展开以下研究:（1）冲击液压胀形下管材合模区和自然胀形区力学行为的理论分析。基于材料力学等系统剖析了管材在成形过程中合模区和自然胀形区的受力情况,得到了相关的力学平衡公式,构建了液压力与型腔体积改变量的数学模型,并根据弹塑性理论等分析了管材自然胀形区的应力应变情况,得到了应力应变与液压力的数学模型,以及构建了接触压力和残余接触压力的数学模型。（2）冲击液压胀形下管材自然胀形区力学行为的数值模拟分析。基于管材冲击液压胀形的工作原理,本文系统介绍了ANSYS与DYNAFORM联合使用的数值模拟方法,通过ANSYS获取了不同载荷参数下的液压力曲线,发现AA6010单层管的破裂极限液压力值约为17Mpa,SS304单层管未破裂,模具越小,液压力值越大,液压力与速度无明显联系,双金属复合管的破裂极限液压力值约为30Mpa,并且进一步分析了不同载荷参数对管材自然胀形区应力应变的影响规律。（3）冲击液压胀形下管材自然胀形区成形规律的分析。基于已经获取的液压力曲线和DYNAFORM后处理模块,研究了不同载荷参数对管材自然胀形区胀形高度和壁厚分布的影响,并通过管材冲击液压成形极限图分析了管材的破裂情况。（4）管材冲击液压胀形试验研究。开展了冲击液压胀形试验,测量了成形后管材自然胀形区的胀形高度和壁厚分布,并与数值模拟结果进行分析和讨论,进一步验证了管材冲击液压胀形下自然胀形区的成形特性和该方法的可行性。本文基于冲击液压胀形下管材的成形机理,对管材自然胀形区的力学行为和成形规律进行了研究,构建了相关的数学模型,研究了管材自然胀形区的成形特性,并通过数值模拟与冲击液压胀形试验对管材自然胀形区的成形特性进行了验证,为管材冲击液压胀形技术的后续发展奠定基础。

现代制造业领域中,结构轻量化、低成本、低能耗、综合性能较优的材料已是未来发展的主流趋势。然而,目前双金属薄壁管材的复合成形必须依赖于昂贵的供液系统,导致成形复杂、效率低、成本高而限制了其发展。为了解决此问题,本文引进一种先进的成形方法——“双金属薄壁管冲击液压胀形法”,该方法结合液压胀形与冲压成形技术优势,使充满液体且密封的内管受到外部径向合模作用力而发生塑性变形,从而与外管紧密贴合成形。该方法无需供液系统即可实现高效率、低成本的批量生产,具有良好的发展前景。为了研究双金属薄壁管冲击液压胀形,本文在理论分析的基础上,开展有限元模拟与试验研究,全面剖析双金属薄壁管液压力形成机理与成形规律。具体研究内容如下:（1）双金属薄壁管冲击液压胀形的液压力形成机理的研究。首先,描述了双金属薄壁管液压胀形的原理;然后,利用理论分析得出液压力与体积变化之间的数学模型关系式,获取内外管径向冲击液压成形过程的液压力形成机理及变化规律;最后,分析不同模具型腔截面边长和不同内外管间的间隙对双金属薄壁管冲击液压产生的液压力影响与变化规律的研究。（2）基于ANSYS WORKBENCH的双金属薄壁管冲击液压胀形的液压力研究。首先,根据冲击液压胀形法的成形方式,提出了冲击液压成形的有限元模拟方法;然后,详细介绍ANSYS WORKBENCH的分析过程;最后,分析不同初始参数条件对双金属薄壁管冲击液压成形所产生的液压力影响并总结其变化规律。（3）基于DYNAFORM的双金属薄壁管成形数值模拟分析研究。首先,详细介绍了DYNAFORM模拟软件操作方法与研究目的;然后,利用DYNAFORM有限元软件分析轴向补料距离与冲击速度等成形参数对双金属薄壁管的填充性与成形性的影响;最后,总结成形规律并获取成形较优的参数。（4）双金属薄壁管冲击液压胀形的试验研究。首先,详细介绍了一种简单的双金属薄壁管冲击液压胀形装置;然后,以30mm/s的速度对双金属薄壁管进行冲击液压胀形试验;最后,将试验结果与有限元模拟所得相关参数结果进行对比,分析其误差,进一步证明双金属薄壁管冲击液压胀形方法的可行性。通过对双金属薄壁管冲击液压胀形成形机理、成形规律的理论分析、数值模拟与试验验证,获得了良好的研究成果,为双金属薄壁管成形技术的应用与推广提供了理论与实践依据。

The tube hydroforming technology is a rapid-forming technique in multi-way tube integrated and lightweight manufacturing. The forming performance of the multi-way tube under this technology was comprehensively analyzed and summarized in this paper. Firstly, the influencing factors, such as axial feed loading path and internal pressure, forming friction, and die transition fillet, in the process of multi-way tube forming were analyzed and summarized. Secondly, the optimization method of the multi-way tube forming performance in hydroforming was analyzed. Finally, the reduction of hydraulic expansion costs and the development of new hydroforming technologies were expounded. © Published under licence by IOP Publishing Ltd.

为分析层压过程中不同槽型结构挠性基板对光纤应力应变的影响,采用COMSOL软件对光纤埋入不同槽型（U形、梯形、矩形）挠性基板的层压工艺进行仿真,分析槽型结构尺寸对光纤偏移量的影响,得到最优槽型结构。仿真结果表明,光纤埋入矩形槽挠性基板可降低光纤在层压过程产生的偏移量,且最优的矩形槽槽型结构的宽度与深度分别为125、145μm,此时光纤最大应力和最大偏移量分别为19.89 MPa、2.0403μm。

基于结构轻量化特征的管材液压胀形技术（Tube Hydroforming）近年来正得到快速发展。应用该技术成形的中空零部件普遍具有轻质量、高强度、表面质量佳等优点,目前正被逐步推广到航空航天和汽车等领域的零部件设计与制造。然而,该技术在工业生产过程中出现了效率低下、设备成本高等不足。冲击液压胀形技术（Liquid Impact Forming）将传统液压胀形技术和冲压成形技术相结合,通过冲压实现管内压力迅速升高,省去了传统液压胀形技术中复杂的高压供液系统,提高了零件成形效率,具有可预见的研究价值和应用前景。对冲击液压胀形过程中双金属复合管成形特性的研究是对该技术深入研究并推广应用的重要前提,因此本文针对冲击液压载荷作用下双金属复合管展开如下研究:（1）冲击液压载荷作用下管材内压力形成规律的分析。根据管材冲击液压胀形的成形特点,提出了基于ANSYS Workbench的双金属复合管冲击液压胀形数值模拟分析方法,详细介绍了双金属复合管冲击液压胀形内压力形成规律的数值模拟过程,针对不同载荷参数对双金属复合管成形过程中内压力形成规律的影响进行了分析与总结。（2）冲击液压载荷作用下管材成形规律的分析。基于获得的管材成形过程中内压力形成规律,开展了基于DYNAFORM的双金属复合管冲击液压胀形过程数值模拟研究,获得了不同载荷条件下管材的特征参数,分析了不同载荷条件对双金属复合管胀形高度、圆角半径和壁厚分布的影响,并对比了常规成形条件、有保压条件和有预成形条件下管材胀形尺寸参数的区别。（3）双金属复合管冲击液压胀形极限分析。通过对双金属复合管冲击液压胀形成形极限图进行分析,得到了管材在不同模具型腔和有无保压和预成形条件下的成形状态,针对不同载荷参数对管材胀形极限的影响规律进行了具体分析,得到了冲击液压环境下双金属复合管合理有效的成形参数区间。（4）基于响应面法的冲击液压胀形工艺参数优化。结合响应面法和数值模拟,选取壁厚方差、胀形高度和圆角半径作为优化目标,模具边长、合模速度和初始内压力作为优化参数,建立了优化目标和优化参数的响应面模型。针对目标函数进行优化,获得了最优的载荷参数匹配关系,确定了最终优化结果,并通过数值模拟验证了响应面优化结果的可靠性,证明了该响应面模型对冲击液压环境下双金属复合管工艺参数优化的有效性。（5）双金属复合管冲击液压胀形试验研究。对冲击液压胀形试验系统进行了介绍,选取了部分具有代表性的载荷参数进行了冲击液压胀形试验,并将其结果与数值模拟结果对比分析。通过测量所得成形管件的壁厚、胀形高度和圆角半径,验证了冲击液压载荷作用下双金属复合管成形规律和成形特性研究的可靠性。本文针对基于冲击液压载荷作用下双金属复合管内压力产生规律、管材成形规律和胀形极限进行了研究,通过冲击液压胀形试验对管材成形规律和特性进行了验证,为双金属复合管冲击液压胀形技术的后续研究奠定基础。

Rope saw technology played an important role in the field of high hardness material processing due to the high cutting efficiency, low equipment costs, energy saving and environmental protection. However, traditional wire saws can often become too slack for the beaded rope to cut due to reduced tension during the cutting process. A new diamond bead rope adaptive adjustment cutting method is proposed based on the conventional wire saw. Firstly, the three-dimensional structure of the beaded rope self-adjusting wire saw is modeled by SOLIDWORKS. Secondly, the modal analysis of the beaded rope adaptive adjustment wire saw is proposed based on the ANSYS. Thirdly, the kinematic model is established, and the dynamics of adaptive adjustment mechanism of diamond beaded rope wire saw is analyzed and verified by ADAMS. Finally, the mechanical property of the adaptive adjustment mechanism is analyzed by ADAMS and MATLAB co-simulation. The mechanical structure of the diamond wire saw is innovatively designed and its advantages are verified through dynamic analysis and co-simulation. This research IP:provides 203.8.109.10reference On:value Thu,for 09 the Mar optimization 2023 15:10:53 research of wire saw machine in the future.Copyright: American Scientific Publishers