碳纤维增强树脂基复合材料和金属材料连接技术综述:应用和展望（英文）

复合材料(如碳纤维增强树脂基复合材料(CFRP))和金属材料(如钢、铝合金、钛合金等)混合结构有效实现轻量化,并保证结构强度,其应用在飞机、汽车、船舶中迅速增加。先进的基于塑性变形连接的CFRP-金属混合接头重量轻、强度高、适用于复杂多样环境,具有广泛的应用前景。本文综述了不同CFRP和金属连接技术应用范围、接头强度等方面的研究成果。指出了高性能、轻量化、高可靠性的CFRP-金属混合接头进一步研究发展所要解决的问题。     

碳纤维增强树脂基复合材料和金属材料连接技术综述：方法和应用

碳纤维增强树脂基复合材料(CFRP)在航空、汽车、舰船、海洋等工业中用量迅速增加。同时,如铝合金等金属材料在这些工业中仍然广泛应用。因此,CFRP和金属材料之间的连接技术是航空、汽车等此类工业中所面临迫切需要解决和发展的关键问题之一。本文综述了CFRP和金属连接技术的一些研究成果。总结了胶接连接、螺栓连接、焊接、金属插入连接以及基于塑性变形连接(如自穿孔铆接、热铆接、无铆链接、摩擦焊接等)技术的实现和连接材料类型范围。指出了高性能、轻量化、高可靠性的CFRP-金属混合接头进一步研究发展所要解决的问题。     

金属/CFRP异种材料连接技术的研究进展及界面结合机理分析

碳纤维复合材料(CFRP)具有质轻高强、高模量和低膨胀优势，在“陆海空天”等领域应用潜力和需求极大.其中热塑性碳纤维复合材料(CFRTP)近年来快速发展，CFRP和CFRTP与金属结构件的连接技术受到国内外学者和工业界的广泛关注.文中综述了金属材料与CFRP连接的主要技术及界面的结合机理；对比分析了不同连接工艺的成形原理，总结了金属与CFRP连接界面的不同作用效果；结合发展现状及未来工程应用需求，对金属/CFRP高质量连接技术瓶颈的突破方向进行了展望.     

树脂基CFRP/金属异种材料激光连接工艺研究现状

树脂基碳纤维增强复合材料(CFRP)作为新型轻质结构复合材料,广泛应用于航空航天器件的零部件中。CFRP与航空常用金属传统连接主要有胶接和机械连接,但具有一定的局限性。激光连接技术具有能量密度高,可控性好等特点,可用于复合材料和金属的连接。本文针对当前树脂基CFRP与金属(铝合金、钛合金、钢等)激光连接接头成形机理以及接头缺陷进行了综述,同时分析了焊接工艺、组织结构优化以及焊前金属表面处理对接头成形的调控,并对CFRP/金属激光连接的发展趋势提出了展望。     

CFRP/金属异种材料激光连接工艺的研究现状

树脂基碳纤维增强复合材料（CFRP）作为新型轻质结构复合材料,广泛应用于航空航天器件的零部件中。CFRP与航空常用金属传统连接主要有胶接和机械连接,但具有一定的局限性。激光连接技术具有能量密度高,可控性好等特点,可用于复合材料和金属的连接。本文针对当前树脂基CFRP与金属（铝合金、钛合金、钢等）激光连接接头成形机理以及接头缺陷进行了综述,同时分析了焊接工艺、组织结构优化以及焊前金属表面处理对接头成形的调控,并对CFRP/金属激光连接的发展趋势提出了展望。     

纤维增强热塑性树脂基复合材料与金属激光连接研究进展

纤维增强热塑性树脂基复合材料与金属的异质构件在轻量化现代装备中的应用日趋广泛,实现异质构件优质、高效、可靠的连接具有重要的学术意义和工程应用价值. 详细综述了异质接头激光连接原理和界面结合机制,以及连接界面结合强度增强方法和激光连接工艺对连接接头抗剪强度的影响. 通过增强机械结合和化学键结合,同时采用控制激光热输入、施加压力、填充树脂材料等措施抑制缺陷的产生,接头抗剪强度已可以满足工业应用对静载强度的要求. 同时展望了纤维增强热塑性树脂基复合材料与金属激光连接技术的发展趋势.     

镀Cr层对低碳钢与CFRP接头力学性能的影响

以低碳钢与碳纤维增强树脂基复合材料CFRP激光连接接头为研究对象,采用表面电镀工艺在低碳钢表面镀Cr,分析了镀Cr层对低碳钢与CFRP接头剪切强度的影响。结果表明,镀Cr低碳钢与CFRP激光连接接头发生断裂的位置是CFRP内部,断裂后的CFRP依旧粘连着低碳钢基体,镀Cr层的存在明显提高了接头的剪切强度。     

碳纤维增强复合材料(CFRP)与铝合金的搅拌摩擦点焊

在航空航天、汽车等领域中,轻金属-复合材料混合结构的应用逐渐增加,碳纤维增强复合材料(Carbon Fiber Reinforced Poly,CFRP)与铝合金的焊接是亟待解决的难题之一。搅拌摩擦点焊(Friction Spot Welding,FSpW)是一种新型的可用于焊接金属与复合材料的焊接方法。综述近年来关于CFRP与铝合金搅拌摩擦点焊的可行性、影响因素、焊接性能以及接头断裂机理等方面的研究进展,最后展望了未来关于CFRP与铝合金搅拌摩擦点焊的研究热点。     

CFRTP/金属激光连接技术研究取得进展

碳纤维热塑性复合材料（CFRTP）具有比强度高、耐腐蚀、抗疲劳、耐热性好等特点,是轻量化制造的重要材料,在航空航天、新能源汽车领域应用前景广阔.实现CFRTP材料之间及CFRTP与金属材料之间高质量的连接是其应用的一个关键技术.激光连接技术具有速度快、强度高、振动应力、工艺灵活等特点,在CFRTP与金属材料连接上较胶结、机械连接等技术具有优势.     

碳纤维复合材料连接接头的防腐蚀

碳纤维复合材料具有很高的比强度和比刚度,较好的耐疲劳性和可设计性能,近年来得到了广泛的应用。复合材料零件间或复合材料与金属材料间的连接,主要有三种形式:胶接、机械连接和混合连接,其中以机械连接最为常用。在机械连接的接头上,由于金属和碳纤维直接接触,极易产生电化学腐蚀。     

Brazing zirconium alloys with an amorphous rapidly quenched strip brazing alloy

Application of aluminum alloy, which is a typical lightweight material, has been expected to achieve energy saving and prevention of pollution in many kinds of transportation vehicles. While the structure made of whole aluminum alloy, however, is lightweight, it still has problems, such as low mechanical strength and high cost. Hence, a hybrid or joining structure made of aluminum alloy and steel seems to be reasonable because of its light weight and higher strength.

To make a hybrid structure for transportation vehicles, we examined welding by friction stirring between aluminum alloy and low-carbon steel, which could be welded without melted weld materials. As a result, welding between aluminum alloy and low-carbon steel that had a thin intermetallic compound at the weld interface was obtained.

In recent automobile manufacturing, zinc-coated steel has been used for structural parts in general. On welding between zinc-coated steel and other materials such as aluminum alloy, existence of a Zn layer between aluminum and steel has to be taken into account to get a high-quality joint between the materials.

In this study, spot joining between aluminum alloy and several kinds of zinc-coated steels by friction stirring was carried out, and the effect of the coated layer both on the weld strength and weld interface microstructure was investigated. As a result, the joint between aluminum alloy and zinc-coated steel was stronger than that between aluminum alloy and non-coated steel, when the coated layer was removed at the weld interface by plastic flow of aluminum alloy.     

Hybrid joining process for carbon fiber reinforced thermosetting plastic and metallic thin sheets by chemical bonding and plastic deformation

A new joining process for thin metallic and continuous carbon fiber reinforced thermosetting plastic (CFRP) sheets is proposed. This joining process is a hybrid of chemical bonding and plastic deformation, usable for ultra-lightweight structures. In contrast to conventional joining methods, such as rivet joining with an adhesive, the proposed method does not require any additional components and can eliminate holes that would cut the continuous carbon fibers and cause stress concentration. Hence, a smaller weight and a higher joining quality can be attained, especially for thin sheets. Aiming at making comparison and demonstrating the applicability of the proposed hybrid joining method, two thermosetting CFRP sheets with different laminates were used as lap adherends in the experiment. The effects of the deformation temperature, the use of a dummy sheet and the relative positions of the sample and dummy sheet on the joining quality were systematically investigated and optimized. The optimal hybrid joint shows high-quality bonding without delamination or adhesive failure. The tensile shear test of single-lap A2017P-CFRP hybrid joints manufactured under optimal experimental conditions indicates that, compared with adhesive bonding and conventional rivet joining with an adhesive, the proposed joining method has obvious superiority in terms of tensile shear load, slip displacement and absorption energy.     

Zn-Al-Cu基合金无钎剂钎焊泡沫铝的界面结构及力学性能

以Zn--Al--Cu基合金为钎料, 对74.7%---91.6%不同孔隙率的泡沫铝采用无钎剂钎焊方法进行连接实验. 采用OM和SEM观察钎缝组织及界面结构, EDS测定界面元素分布, XRD分析界面物相, 通过热力学分析验证钎料中Cu和Zn与母材中Al元素的相互作用和除膜机理, 对钎焊接头试样进行拉伸和剪切性能实验, 分析孔隙率与接头试样强度之间的关系.结果表明, 该无钎剂钎焊方法在泡沫铝端 面之间形成密实结构的连续钎料层,未改变母材结构特征; 钎缝组织由Al(Zn) 固溶体、Zn(Al) 固溶体、Cu₄Zn及MgMnO₃组成; 连接界面主要由Al(Zn)固溶体组成, Zn,Al和Cu在界面上相互扩散而形成一定扩散梯度, 熔合良好, 钎焊接头抗拉强度与母材相当, 剪切强度略高于相同孔隙率母材的剪切强度,抗拉强度和剪切强度均随孔隙率增加而明显降低.     

Dissimilar materials joining of metal/carbon fibre reinforced plastic by resistance spot welding

ABSTRACT

Dissimilar materials joining of metal to carbon fibre reinforced plastic (CFRP), which consisted of PA6, modified polypropylene (PP) or polyphenylene sulphide (PPS) as matrix polymer with short carbon fibre, was performed using series resistance spot welding (series-RSW). The metal plate was placed on CFRP plate as the lap joint, and electrodes of series-RSW were pressed only on the metal plate side. The metal around the electrode was heated by electrical resistance heating, and the thermoplastic near the interface was slightly melted by the heat conduction from heated metal. The objectives of this research are to confirm the possibility of direct joining of CFRP and metal, and to investigate the effects of the heat input during series-RSW, silane-coupling treatment and chemical structure of matrix plastics on the joint properties.

The direct joint formations of SUS304 to CFRP (PA6) and CFRP (PP) were accomplished, and CFRP (PPS) was not. The joining area, which corresponding to the melted area of CFRP, enlarged with increasing the welding current and welding time, therefore, the tensile shear fracture load also increased. The silane-coupling treatment for metal surface was highly effective to increase the joining strength. The maximum tensile shear strength of about 13 MPa was obtained for SUS304/CFRP (PA6) joint.     

Friction riveting (‘FricRiveting’) of 6056 T6 aluminium alloy and polyamide 6: influence of rotational speed on the formation of the anchoring zone and on mechanical performance

Metal-polymer hybrid structures can be used as an alternative solution for reducing weight and fuel consumption in the transport industry, which aims to minimise the emission of harmful gases that have a greenhouse effect. Friction riveting is a relatively new technique for joining metal-polymer hybrid structures. The process is based on the generation of frictional heat between the components, resulting in the plastic deformation of the end of the metal rivet, which is anchored inside the polymer component. This study assessed the technical feasibility of joining AA 6056 T6 and PA6, focusing on the influence of the rotational speed of the rivet on the mechanical performance of the joints. The maximum temperature reached during the process increased with the rotational speed, from 291 ± 6 °C with 10,000 rev/min to 375 ± 5 °C with 15,000 rev/min. The use of higher rotational speeds led to the tip of the rivet undergoing plastic deformation during the friction phase. This produced mechanically stronger joints, because the metal rivet was anchored more securely in the polymer block. The AA 6056 T6-PA6 joints perform well in terms of tensile strength, reaching 85% of the tensile strength of the metal rivet. We therefore confirmed that it is possible to join AA 6056 T6 and PA6 using the technique of friction riveting, and that rotational speed directly affects the tensile strength of the joints.     

Multi-scale structuring for thermoplastic-metal contour joints of hollow profiles

In contrast to common and classical joining technologies for composite/metal hybrid structures such as bonding and riveting, profile and contour joints offer a promising potential for novel lightweight hybrid structures. Contour joints with form locking elements on multiple scale levels enable to pass very high loads into rod- and tube-shaped fibre reinforced structures and promise high degrees of material utilization for the composite part. This paper demonstrates the advantage of multi-scale structured load introduction elements. First the intrinsic manufacturing process, whereas the thermoplastic tape braided preform is simultaneously consolidated and formed into the metallic load introduction element is shown. Numerical investigations on the macro- and generic microscale demonstrate the potential to trigger cohesive or adhesive failure by appropriate designed form locking elements. The extensive experimental investigation of meso-, macro- or combined-structured tubular specimen shows the beneficial effect of multi-scale structuring to increase the joining strength. Concluding advises for the contour joints’ design are given.     

LF6铝合金搅拌摩擦点焊

搅拌摩擦点焊(FSSJ)是近年来发明的新的点焊方法,具有接头强度高、能耗低和设备简单等优点,在汽车行业焊接轻质合金如铝合金、镁合金等具有很好的应用前景.采用自行设计的搅拌头对1 mm 1 mm的LF6铝合金进行了搅拌摩擦焊试验研究.试验结果表明,接头剪切强度约是电阻点焊的1.56倍.接头可以分为搅拌区和热影响区,搅拌区的材料受到搅拌头的作用发生圆周运动和轴向运动,形成细小的再结晶晶粒,强度高、塑性好.     

Joining stainless steel metal foams

Abstract

Metallic foams produced from stainless steel are one of the most recently developed ultralightweight materials. These foams have very low densities and high energy absorption capacities and are therefore expected to have widespread applications in the manufacture of ultralightweight structural components. The fabrication of load bearing structural components such as implants, and high temperature air or fluid filters, are potential application areas depending on the form of the cell structure of the foam. Closed cell metal foams are typically suitable for structural uses whereas open cell foams tend to be preferred for functional applications. Development of adequate joining technologies for these materials is an essential step for their widespread industrial utilisation. The present paper describes a brazing method that is capable of providing excellent joints between 316 stainless steel foams and a conventional 316 stainless steel bulk alloy. Having optimised the bonding conditions and using a Cu–Ti alloy as the filler metal, bonds between a foam and a bulk alloy were produced. No apparent plastic deformation of the metal foam occurred in the course of the 10 min length brazing process, and the resulting bonds had tensile strengths higher than that of the stainless steel foam.     

Dissimilar Ti/Mg alloy butt welding by fibre laser with Mg filler wire – preliminary study

Abstract

A fibre laser was used to join Ti–6Al–4V alloy to AZ31B Mg alloy with the same thickness of 2 mm, and a filler wire was used to avoid weld underfill resulting from Mg vaporisation. The acceptable joints were only obtained when the laser beam was offset from the edge of the weld seam at 0·2 mm to the AZ31B side of the joint. Cross-weld tensile testing found joint strengths of up to 200·3 MPa, which is 85·1% of the AZ31B tensile strength. All the joints were fractured at the Ti/fusion zone interfacial layer. When the laser offset increased from 0·2 to 0·3 mm or laser power reduced to 1·2 kW, the joining mode of the interfacial layer changed from a semimetallurgical joining with high strength to a mechanical joining with poor strength. Moreover, the fracture surface of acceptable joints was characterised by scraggly remaining weld metal, while that of poor joints was almost only characterised by smooth Ti surface.     

Joining of high strength steel and aluminium alloy sheets by mechanical clinching with dies for control of metal flow

High strength steel and aluminium alloy sheets were joined by mechanical clinching with dies for control of metal flow. Since the sheets undergo plastic deformation for the joining during the mechanical clinching, the high strength steel sheets tend to fracture due to the small ductility. For the upper high strength steel sheet, fracture was caused by the concentration of deformation around the corner of the punch, and cracks were caused by the tensile stress generated in the bulged bottom into the groove of the die for the lower high strength steel sheet. To prevent these defects, metal flow of the sheets was controlled by optimising a shape of the die. For the upper high strength steel sheets, the depth of the die was decreased to prevent the concentration of deformation around the corner of the punch. On the other hand, the groove of the die was eliminated to reduce the tensile stress for the lower high strength steel sheets. The sheets below SPFC780 and SPFC980 were successively joined with the aluminium alloy sheet for the upper and lower high strength steel sheets, respectively.