摘要
在交通运输和电子等行业,产品的能源消耗大、成本高,使得人们追求更轻、强度更高的产品。特别是在电子封装领域,与轻质、易加工、高强度的金属/树脂复合材料相比,纯金属或者纯树脂产品已逐渐失去竞争力。金属/树脂复合材料是指金属与树脂以某种形式粘接起来的复合材料,除粘接界面是两相相互贯穿的复合体外,其余部分以各自体相单独存在。因粘接界面间的化学作用和较强的物理锚栓作用,复合材料具有较强的粘接性能,而非界面区域两相的单独存在使得复合材料具有金属与树脂双重特性。金属/树脂复合材料的最大技术难点在于如何实现金属与树脂两相界面的牢固粘接。由于金属与树脂的性质差异较大,这种复合材料的加工方法不同于金属之间的焊接加工,也不同于树脂之间的熔融共混。因此,如何高效地制得低成本、性能优异的金属/树脂复合材料已成为这一领域的研究热点。目前,金属/树脂复合材料的加工方法主要有层压、激光焊接、摩擦叠焊、搅拌摩擦焊、超声焊接和纳米注塑等。其中,层压法只能用于制备结构简单、尺寸较大的产品;激光焊接、摩擦叠焊和搅拌摩擦焊会损伤制品表面,影响美观;超声焊接工艺复杂。而纳米注塑成型技术(Nano-molding technique,NMT)可实现金属/树脂复合材料的一体化制备,同时兼顾两相的粘接强度和制品的灵活设计,从而成为制备金属/树脂复合材料的重要技术方法并得到广泛研究。为了制得性能优异的金属/树脂复合材料,NMT的原理与工艺技术被不断探索与完善。目前较为被认可的NMT原理是:胺系化合物和特定树脂发生反应并产生热量,促进树脂在纳米孔中的流动;嵌入金属表面的树脂固化后在两相间形成锚栓作用,极大地增强了两相界面的粘接强度。NMT所适用的金属由原来的铝合金推广到了铜、不锈钢、钛、镁等金属。所用的树脂也由原先的几种工程树脂扩展到了聚苯硫醚(PPS)、聚对苯二甲酸丁二醇脂(PBT)、聚醚醚酮(PEEK)、聚邻苯二甲酰胺(PPA)和聚酰胺(PA)等一系列树脂。文章重点概述了NMT技术的粘接原理、工艺流程、性能测试、技术研究进展以及相关应用,并对其今后发展方向与亟待解决的问题进行了相关讨论。
The large energy consumption and high cost in the fields of transportation and electronics industries have been triggering the urgent demand for lighter and stronger products.Especially in the field of electronics packaging,metal/polymer composites have gradually prevailed over metallic or polymer materials due to their lightweight,easy processing and high strength.Metal/polymer composites consist of metal and polymer phases which combined with each other by interpenetrating interfaces.The chemical interaction and physical anchor effect endow with high bonding strength of the resultant composites.Despite of the interfaces between two phases,metal and polymer still exhibit their own intrinsic properties.How to achieve the strong bonding between metals and polymers is the biggest challenge to the fabrication of metal/polymer composites.Owing to the property disparity between metals and polymers,the processing techniques applicable for metal/polymer composites are quite different from either welding for metals or melt mixing for polymers.The development of an efficient and lowcost processing technique to obtain high-performance metal/polymer composites has hence become a hot topic in this field.The currently feasible routes to produce metal/polymer composites include lamination,laser bonding,friction stitch welding,friction stir welding,ultrasonic bonding and nano-molding.Among them,lamination can only be used to fabricate products with simple and large-size structure.Laser bonding,friction stitch welding and friction stir welding could induce scars to the surfaces of products.Ultrasonic bonding needs relatively complicated processing procedures.In comparison,nano-molding technology（NMT）can achievethe integrated fabrication of metal/polymer composites while mutually ensure the strong bonding between metal and polymer as well as the flexible design of products.Therefore,NMT has acquired extensive research interest as a predominant processing technique for fabricating metal/polymer composites.For the sake of manufacturing more favorable metal/polymer composites,there have been continuous endeavors to explore and improve the mechanism and process regime of NMT.By now,the basically recognized mechanism of NMT is：Ⅰ.The heat generated by exothermic reactions between amine compounds and polymers promotes the flow of polymer melt in nanostructures on the metal surface;Ⅱ.The solidification of polymers embedded in the metals forms the＂anchors＂at the polymer/metal interface,thereby significantly enhancing the composite＇s bonding strength.The metals applicatory for NMT have been extended from aluminum alloy to copper,stainless steel,titanium and magnesium,also,the polymer species which can be adapted for NMT have proliferated to a range of resins such as PPS,PBT,PEEK,PPA and PA.This review gives summary descriptions over the bonding mechanism,manufacture processes,performance test,technological advances and applications with respect to NMT,as well as a prospective discussion on the future development trends and some unresolved key problems.
作者
李颖
梅园
王颖
孟凡彬
周祚万
LI Ying;MEI Yuan;WANG Ying;MENG Fanbin;ZHOU Zuowan(College of Material Science and Engineering,Southwest Jiaotong University,Chengdu 610031)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第13期2295-2303,共9页
Materials Reports
基金
四川省支撑计划项目(2016GZ0229)
四川省科技支撑计划(2016GZ0224
2016CZYZF0003)
中央高校基本科研业务费(2682016CX069)
