Effect of Interface on Mechanical Property of Steel-mushy Al-20Sn Bonding Plate

1 IntroductionSteel-Al-20Sn bonding plate is an ideal material ofneotype bearing[1-3].Almost one milliontons of this bond-ing plate are needed in machinery and automobile fieldannually[4-6].Forthis bonding plate ,theinterfacial struc-ture is very important .It determines the interfacial me-chanical property.Broadly,there are there kinds of inter-face for steel-Al-20Sn bonding plate .For solid steel plateto solid Al-20Sn bonding plate ,the interface is basicallymade upof Fe-Al solidsolution…     

Ratio of Fe-Al compound at interface of steel-backed Al-graphite semi-solid bonding plate

The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interfacial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters (such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interfacial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.     

The Influence of Preheat Temperature of Steel Plate on Steel-mushy Cu-graphite Bonding

The pressing bonding of steel plate to QTi3.5-3.5 graphite slurry was conducted. Under the conditions of 530 ℃ for the preheat temperature of dies, 45% for the solid fraction of QTi3.5- 3.5 graphite slurry, 50 MPa for the pressure and 2 min for the pressing time, the relationship between the preheat temperature of steel plate and interfacial mechanical property of bonding plate was studied. The results show that when the preheat temperature of steel plate is lower titan 618 ℃ , the interfacial shear strength of bonding plate increases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is higher than 618 ℃ , the interfacial shear strength decreases with the increasing of the preheat temperature of steel plate. When the preheat temperature of steel plate is 618 ℃ , the highest interfacial shear strength of bonding plate of 127.8 MPa can be got.     

Influence of diffusion time on property of steel—aluminum solid to liquid bonding

The bonding of solid steel to liquid aluminum was conducted using rapid solidification.The influence of diffusion time on interfacial shear strength was studied.The results show that when the temperature of aluminum liquid is 700℃and the preheat temperature of steel plate is 250℃,the relationship between diffusion time(t) and interfacial shear strength(σ)is σ=15.1 8.14t-0.37t 0.005t^3,and the maximum interfacial shear strength is 71.1MPa.     

Relationship between interfacial structure and property of steel-mushy Al-28Pb bonding-pate

1INTRODUCTION SteelAl28Pbbondingplateismadeupof steelplateandAl28Pballoylayer[13].Steelplate hasahigherstrength,andAl28Pballoylayerhasexcellentheatconductivityandperfectlubricating property.Thusthisbondingplateisanidealmate rialofneotypebearingwhichiswidelyneededinmachineryandautomobilefields[46].Forthis bondingplate,theinterfacialmechanicalproperty thatdeterminesthesafetyofproductisveryim portant.Thehighertheinterfacialmechanicalproperty,thesafertheproduct.Interfacialmechanicalpropert…     

Thickness of compound layer in steel-aluminum solid to liquid bonding

The bonding of solid steel plate to liquid aluminum was studied using rapid solidification. The surface of solid steel plate was defatted, descaled, immersed (in K2ZrF6 flux aqueous solution) and stoved. In order to determine the thickness of Fe-AI compound layer at the interface of steel-aluminum solid to liquid bonding under rapid solidification, the interface of bonding plate was investigated by SEM (Scanning Electron Microscope) experiment. The relationship between bonding parameters (such as preheat temperature of steel plate, temperature of aluminum liquid and bonding time) and thickness of Fe-AI compound layer at the interface was established by artificial neural networks (ANN) perfectly. The maximum of relative error between the output and the desired output of the ANN is only 5.4%. From the bonding parameters for the largest interfacial shear strength of bonding plate (226℃for preheat temperature of steel plate, 723℃ for temperature of aluminum liquid and 15.8 s for bonding time), the reasona     

Semi—solid Processing of Steel—Al—7 Graphite BInding Plate

The bonding of steel plate to Al-7 graphite slurry was studied for the first time.The relationship model about preheat temperature of steel plate,solid fiaction of Al-7 graphite slurry,rolling speed and nterfacial shear strength of bonding plate could be established by artificial neural networks perfectly.This model could be optimized with a genetic algorthm.The optimum bonding parameters are :516℃ for preheat temperature of steel plate,32.5% for solid fraction of Al-7 graphite slurry and 12mm/s for rolling speed,and the largest interfacial shear strength of bonding plate is 70.6MPa.     

Influence of aluminum solid fraction on property of steel-mushy aluminum bonding plate

The interfacial shear property of steel-mushy aluminum bonding plate was studied, and the relationship between aluminum solid fraction and the interfacial shear strength of bonding plate was determined. The results showed that when aluminum solid fraction is 34.3 %, the maximum interfacial shear strength of bonding plate is 71 .0 MPa.     

The Bonding Properties of Solid Steel to Liquid Aluminum

The bonding of solid steel plate to liquid aluminum was studied using rapid solidification. The relationship models of interfacial shear strength and thickness of interfacial layer of bonding plate vs bonding parameters ( such as preheat temperature of steel plate, temperature of aluminum liquid and bonding time ) were respectively established by artificial neural networks perfectly. The bonding parameters for the largest interfacial shear strength were optimized with genetic algorithm successfully. They are 226℃ for preheating temperature of steel plate, 723℃ for temperature of aluminum liquid and 15.8s for bonding time, and the largest interfacial shear strength of bonding plate is 71.6MPa. Under these conditions, the corresponding reasonable thickness of interfacial layer (10.8μm) is gotten using the relationship model established by artificial neural networks.     

Immersing Treatment of Steel Plate Surface in Steel-Aluminum Solid to Liquid Bonding

The interfacial status of the steel-aluminum solid to liquid bonding plates (their steel plate surfaces were or were not immersed in flux aqueous solution) were measured by using SEM (Scanning Electron Microscope) and X-ray diffraction . The results showed that the layer of flux (the minimum thickness was 15 μm on the steel plate surface) could protect the steel plate surface from oxidizing effectively at high temperature in solid to liquid bonding. The melt temperatUre of the flux should be lower than 580 ℃ so that it could be melted and removed completely. No. 1 flux (patent product made by the author) made up of halogeindes could also force liquid aluminum to infiltrate into steel plate surface and thus the interfacial shear strength of the bonding plate was rather large.     

铝合金板与混凝土的粘贴粘结强度研究

为了在提高加固钢筋混凝土梁承载力的同时具有很好的延性和耗能能力,特别是满足侵蚀环境及寒冷环境中加固工程的需要,采用铝合金板加固钢筋混凝土梁是一个很好的解决办法。铝合金板通过粘贴层将力传给钢筋混凝土梁,故铝合金板与混凝土的粘贴粘结性能决定了铝合金板加固钢筋混凝土梁的效果。铝合金板与混凝土的粘贴粘结强度作为铝合金板加固钢筋混凝土梁连接设计的基础,对其开展试验和理论研究。开展105个试件的铝合金板与混凝土面内单剪试验发现：对粘贴界面没有进行粗糙处理的试件发生了界面剥离破坏,其他试件均发生了混凝土层剥离破坏;界面剥离破坏的粘结性能远差于混凝土层剥离破坏,说明了对粘贴界面进行处理的必要性。通过试验得到铝合金板和混凝土连接的极限粘结荷载,根据铝合金板正应力的变化率与粘贴界面剪应力的关系,得到剪应力的分布曲线和有效粘结长度;假设剪应力沿有效粘结长度处处相等,得到了铝合金板与混凝土的粘贴试验粘结强度,并基于此讨论了界面处理、混凝土强度、铝合金板宽度、厚度和粘贴长度等因素对试验粘结强度的影响。结合试验数据的统计回归分析,提出计算铝合金板与混凝土的粘贴粘结强度的修正Niedermeier模型,得到了铝合金板与混凝土的有效粘结长度和粘贴粘结强度的理论计算公式,其理论值和试验值吻合较好,误差最大值为8.98%,平均值为0.004,标准差为0.041。研究成果为铝合金板加固钢筋混凝土梁的粘贴设计提供了理论基础。     

CFRP布混合粘贴形式界面剪切性能试验

为了研究CFRP布混合粘贴的界面粘结性能,设计了4组自锚式面内双剪试验.根据界面剪应力的发展规律,将CFRP布混合粘贴中碳纤维布由初始受力至破坏的过程划分为3个阶段.试验考虑了碳纤维布不同的粘贴长度因素,分析试验中的破坏形式、破坏过程和界面粘结性能.研究表明CFRP布混合粘贴形式中的钢板锚固件提高了CFRP-混凝土界面的粘结强度,将破坏形态由碳纤维布的剥离破坏转变为碳纤维布的断裂破坏,极大地的提高了碳纤维布材料的强度利用率.碳纤维布在未剥离阶段其界面粘结性能较为稳定,钢板锚固件对碳纤维布的初始剥离影响较小;在碳纤维布持续剥离阶段,钢板锚固件可以延缓碳纤维布的剥离,使得界面粘结强度提高18.02%.     

无机胶粘贴铝合金板与混凝土界面黏结性能试验

为满足耐环境侵蚀及较高使用温度要求而采用的无机胶粘贴铝合金板加固混凝土结构,需解决铝合金板、胶与界面的黏结问题.以黏结长度为基本参数,分别采用硫铝酸盐水泥浆、磷酸镁水泥浆及碱激发矿渣浆三种无机胶粘剂,将3 mm厚铝合金板粘贴至素混凝土试块,完成了无机胶粘贴铝合金板与混凝土界面双剪性能试验.试验结果表明:铝合金板、胶层与界面黏结性能随黏结长度与胶粘剂种类不同而不同,破坏时主要表现为铝合金板脱粘、胶层失效及界面失效三种典型形态;发现相同黏结条件下,三类无机胶粘贴铝合金板与混凝土界面黏结强度中,磷酸镁水泥最大、硫铝酸盐水泥其次、碱激发矿渣最小.基于实测的界面黏结-滑移关系,获得了适用于不同胶粘剂的有效黏结长度取值方法,提出了与试验结果吻合较好的三类无机胶黏结强度-滑移关系模型.可为粘贴铝合金板加固混凝土受弯构件用无机胶粘剂优选提供参考.     

耐碱玻璃纤维与树脂界面剪切强度的实验测定

玻璃纤维筋具有耐腐蚀性,可以克服钢筋易锈蚀的缺点,在工程中有良好应用前景.玻璃纤维筋是由耐碱玻璃纤维和乙烯基脂树脂组成的复合材料,其性能受很多因素影响,而界面剪切强度是复合材料设计的重要指标,采用单纤维埋入法(SFM)测定这一参数,对基体力学性能对界面剪切强度的影响进行了研究,得出一些结论,这些结论无疑会对玻璃纤维筋的优化设计提供依据,为玻璃纤维筋在工程中的应用提供理论基础.     

L形截面双钢板组合剪力墙受力性能有限元分析

双钢板组合剪力墙结构因其整体性好、刚度大、抗剪承载力高等优点而广泛应用于高层建筑,国内外学者对其进行了大量研究,研究主要集中在“一”字形和T字形截面形式,对L形截面形式研究较少。本文在已有试验的基础上,分析了L形截面双钢板组合剪力墙结构的受力特点,通过有限元软件ABAQUS对L形截面双钢板组合剪力墙分析建模,与试验结果进行了对比,结果表明有限元模拟与试验结果较吻合;然后通过有限元参数化建模,研究了轴压比、钢板厚度、钢板强度、混凝土强度、端部H型钢尺寸等主要参数对剪力墙滞回性能的影响规律及其特征。研究结果表明,增加钢板厚度及端部H型钢尺寸、提高钢板强度及混凝土强度都会提高L形截面双钢板组合剪力墙承载力。其中钢板厚度及在无翼缘腹板处增设H型钢是影响承载能力的主要因素。最后,对L形截面双钢板组合剪力墙的设计轴压比建议不宜大于0.4。     

硅烷涂层提升钢纤维-砂浆界面性能的试验研究

为了提升钢纤维-砂浆界面的黏结性能,采用9种基于硅烷的表面处理剂对钢纤维进行浸渍处理并高温固化成膜;埋置于水泥砂浆圆柱体试块中,开展单根纤维拉拔试验,获得拉拔荷载-位移曲线. 试验结果表明,采用不同的硅烷涂层对钢纤维进行表面改性,可以不同程度地改善钢纤维-砂浆界面的黏结性能;拉拔峰值荷载最高增加5.75倍,拉拔能耗最多增加2.48倍. 硅烷Z6011和Z6020及复合涂层能够较大幅度地提升界面黏结强度,主要增加钢纤维与砂浆界面的化学黏结力;硅烷Z6030和Z6040及复合涂层对界面黏结强度的提升幅度相对较小,主要增加界面滑移摩擦力. 采用扫描电子显微镜（SEM）研究界面黏结性能的提升机理,发现硅烷涂层使得界面过渡区的微观结构更致密,显著提升了钢纤维-砂浆之间的黏结性能.     

铝合金板与混凝土的粘结性能

铝合金材料具有强度高、变形性能好、耐腐蚀等优点,是沿海侵蚀环境中钢筋混凝土结构加固工程的理想材料;而铝合金板与混凝土的粘结性能是铝合金板加固钢筋混凝土梁能否协同工作的关键问题。基于此,对铝合金板与混凝土的粘结性能进行试验和理论研究。考虑混凝土强度、铝合金板宽度和厚度、粘贴长度及界面处理等因素对铝合金板和混凝土块体粘结性能的影响,设计了一套试件固定装置,采用万能试验机对105个铝合金板与混凝土棱柱体的粘贴试件进行了面内单剪试验。根据试验结果,结合理论分析,得到了铝合金板和混凝土连接的粘结破坏典型特征、剪应力分布曲线和粘结滑移曲线。研究表明,试件存在两种破坏形式：界面剥离破坏和混凝土层剥离破坏。界面处理对粘结性能有重要的影响,粘贴界面没有进行糙化处理的试件发生了界面剥离破坏,其他试件发生了混凝土层剥离破坏;随着混凝土强度的提高、铝合金板宽度和厚度的变小,粘结性能提高;存在一个有效粘贴长度,当粘贴长度大于有效粘贴长度后,增大粘贴长度并不能提高连接的极限荷载。     

Ni-Cr合金烤瓷材料界面组织结构和力学性能

应用扫描电镜、能谱、X射线衍射及电子拉伸试验机对Ni-Cr合金与烤瓷材料的界面组织结构与力学性能进行了分析。结果表明:Ni-Cr合金烤瓷制作过程中产生残余应力和缺陷将导致瓷崩、瓷裂、剥离或脱落。烤瓷温度T对金-瓷界面剪切结合强度影响较大,T=990℃、保温时间t=1.0 min时,金-瓷界面剪切结合强度可达到37.52 MPa。在金-瓷界面处由于Ni-Cr合金与熔融的玻璃相烤瓷材料相互作用,形成新的化合物型界面,对提高金-瓷界面结合强度将起到非常重要的作用。     

A Novel Method to Fabricate Steel-Al Foam Sandwich Panel with Metallic Bonding

Al foam sandwich panel(AFS) with metallic bonding was fabricated by foaming a hotpressed three-layer composite with two steel facesheets and a melt route precursor as core. The melt route precursor was fabricated by dispersing undecomposed blowing agent into molten Al, followed by solidification. Microstructures of the joints during fabrication process were analyzed by scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS). Static three-point bending was conducted to evaluate joint quality of the AFS. It was found that a primary bonding was achieved by hot-pressing and significant diffusion layer of Fe-Al intermetallic compounds was sustained between steel and Al foam core by foaming. Damage modes of the AFS under three-point bending were dominated by indentation, plastic hinges, core shear and crack. Delamination between steel and foam was absent, implying that reliable metallic bonding was achieved. This method allows for producing large-scale AFS with steel facesheets.     

全金属组元铁基块体非晶的制备与性能研究

3D打印成型碳纤维接枝碳纳米管增强热塑性复合材料的强度提高

王婼楠¹，吴海宏^1，2，郭子月³，刘春太²，申长雨²

（1. 河南工业大学 机电工程学院，郑州450001; 2.郑州大学 橡塑模具国家工程研究中心，郑州450002; 3.中山大学 数学学院（珠海）,珠海519082）

创新点说明：

1) 研究了碳纤维定量接枝碳纳米管对热塑性复合材料的界面性能及拉伸性能的影响。

2) 用3D打印模压成型的工艺方法制备了热塑性复合材料。

研究目的：

研究碳纤维表面接枝不同含量的碳纳米管对复合材料微观结构、界面性能和力学性能的影响。

研究方法：

1) 采用溶液法，通过控制碳纳米管接枝反应时间，制备不同含量碳纳米管接枝碳纤维，然后用硝酸刻蚀法，去除残留溶剂，验证了碳纳米管接枝的可靠性。用扫描电镜观察碳纤维的微观形貌，用FTIR测试碳纤维表面官能团并用XPS对碳纤维的表面官能团进行分析。

2) 用扫描电镜观察碳纤维与基体的结合情况并用接触角测量仪测试碳纤维与基体的接触角。

3) 通过 3D打印成型法成型了热塑性复合材料样条，并用扫描电镜观察碳纤维热塑性复合材料的界面微观形貌。

4) 采用万能试验机测试3D打印成型热塑性碳纤维复合材料的拉伸性能，并观察复合材料断口形貌。

结果：

1) 溶液法.扫描电镜观察发现碳纳米管在碳纤维表面均匀分布，表明碳纤维与碳纳米管之间存在较强的键合关系。但随着接枝时间的增加，碳纤维表面的碳纳米管含量逐渐增加，但达到0.4%时，出现分散不均匀现象。碳纤维表面含有上浆剂和去掉上浆剂的对比发现，无上浆剂的碳纤维表面沟壑明显，这些沟槽可以增加碳纤维的比表面积和表面能，增强了基体与碳纤维的机械相互作用。用FTIR测试碳纤维表面官能团并用XPS对碳纤维的表面官能团进行分析，结果表明，经偶联剂改性后，C=O键含量明显增加，碳纤维表面引入含氧官能团。C1，O1S峰增强，表明碳纳米管接枝到了碳纤维表面。

2) 扫描电镜结果表明，与表面未接枝碳纳米管的碳纤维相比，接枝碳纳米管的碳纤维与基体PA6具有更好的润湿性。接触角测试结果对比发现，接枝碳纳米管的碳纤维与基体的接触角，明显小于未接枝碳纳米管的。

3) 通过扫描电镜观察复合材料的界面微观形貌，结果表明：纤维与基体之间存在一定厚度的界面层，界面层的存在可以减轻纤维与基体之间的力学性能突变引起的应力集中，并防止界面缺陷的扩展。

4）界面结合强度测试结果表明，当碳纳米管的质量分数增加到0.25%时，复合材料的界面结合强度比未接枝碳纳米管的碳纤维增强的PA6复合材料提高了20%，比表面有环氧的碳纤维复合材料提高了41.8%。然而当碳纳米管含量大于0.4%时，界面结合强度不再继续增加。力学测试表明碳纳米管含量为0.25%的复合材料具有最高的平均模量、拉伸强度和界面剪切强度。接枝碳纳米管的碳纤维复合材料断口形貌可以观察到界面处基体中的韧窝。表明基体树脂在拔出纤维前经历了较大的塑性变形，表明纤维与基体有很好结合性。

结论：

实验结果表明，碳纳米管可以提高表面的润湿性和CF表面粗糙度。碳纳米管接枝碳纤维增强PA6与环氧上浆的碳纤维复合材料相比，当碳纳米管的质量分数达到0.25%时，复合材料的界面结合强度增加了41.8%，拉伸强度提高了130%，界面剪切强度提高了238%。然而，随着碳纳米管含量的继续增加到0.4%时，界面结合强度和力学性能就会下降。

关键词：热塑性复合材料，界面结合强度，界面剪切强度，3D打印成型