航空用钛合金的胶接

本文简要介绍了航空用钛合金的优异性能,并论述了钛合金胶接连接的优点。文中指出了不同的表面处理方法会明显地影响钛合金的胶接性能,并推荐了一种效果较好的钛合金表面处理方法。还介绍了国外胶接钛合金的聚酰亚胺胶粘剂的有关性能及胶接工艺规范。     

钛合金表面阳极化处理对钛合金／复合材料胶接性能的研究

通过碱性阳极化方法NaTESi处理钛合金,碳纤维复合材料胶接试件中钛合金的表面。主要研究了阳极化前碱洗酸洗、阳极化过程中的电压、温度、时间以及该方法与喷砂法结合对处理后的钛合金胶接试件胶接性能的影响。结果表明：钛合金阳极化前的碱洗酸洗能提高钛合金／碳纤维复合材料胶接试件的粘接强度,阳极化过程中,电压在8-12V,温度在15。25％,时间在15．25min之间时处理出的钛合金所制成的胶接试件有较好的湿热耐久性能;喷砂法与NaTESi阳极化法配合处理钛合金表面,可使钛合金,碳纤维复合材料胶接试件湿热耐久性能得到进一步的提高。     

钛合金胶接接头耐水性的研究

本文介绍了几种表面处理方法对钛合金胶接性能的影响，并讨论了钛合金胶接接头的耐水性能。     

复合材料风扇叶片钛合金加强边胶接技术研究

本文以航空发动机复合材料风扇叶片钛合金加强边胶接为研究背景,开展钛合金/复合材料胶接技术研究,着重研究了基于AF191胶膜的钛合金/复合材料胶接工艺参数、不同结构复合材料与钛合金以及不同表面处理方式钛合金与复合材料胶接强度。结果显示:采用热压罐固化,并且在加压0.1 MPa后卸掉真空更有助于胶接;不同结构复合材料对胶接强度影响较大,刚度更高的复合材料表现为更好的胶接强度;采用酸洗和阳极化处理钛合金表面均能大幅提高胶接强度,并且配合表面预处理剂使用更佳。     

复合氧化工艺对医用钛合金耐蚀性和耐磨性的影响

采用阳极氧化和热氧化相结合的复合氧化工艺对医用钛合金进行氧化处理,研究了氧化液的组成和热氧化温度对钛合金氧化膜表面形貌,耐蚀性和耐磨性能的影响。实验结果表明,复合氧化工艺可以提高钛合金表面的耐蚀性能和弹性模量,改善了钛合金的耐磨损性能。     

高性能航空KH-CL-RTV-2型硅橡胶胶粘剂的粘接工艺研究

以高性能航空KH-CL-RTV-2型硅橡胶作为胶粘剂,采用单因素试验法着重考察了固化工艺、稀释剂用量、金属基材、单双面喷胶、胶层厚度和填料等因素对胶粘剂粘接强度的影响,从而优选出胶接件的最佳施胶工艺;最后利用硅橡胶黏度-时间曲线对胶接件的固化过程进行了验证和解释。研究结果表明:稀释剂环己烷用量对胶接件的粘接强度无影响;胶接件的最佳施胶工艺是双面喷胶、胶层厚度为0.50 mm、被粘基材为除油打磨处理后的铝合金、固化温度为50℃和固化时间为36 h,此时胶接件的粘接强度(为3.04 MPa)相对较大。     

碳纤维复合材料结构修理用胶黏剂应用研究

介绍了复合材料结构胶接修理常用胶黏剂的基本类型和应用情况,对比分析了不同胶黏剂的力学特性,并从胶接件表面处理、固化工艺、无损检测等方面介绍了胶结修理中胶黏剂应用的关键工艺。着重从胶黏剂的自身性能出发,对比贴补和挖补两种胶接修理方式,详细讨论了胶黏剂对胶接修理参数选择的影响。最后,对胶接修理后结构的抗冲击和耐湿热性能方面的研究作了总结,旨在为胶黏剂的破坏机理研究和工艺改进提供参考。     

直升机桨叶包片胶接前激光毛化处理的有效性研究

为提升直升机桨叶包片胶接质量,开展激光毛化技术在不同材料包片胶接前表面处理工艺中的有效性研究.分别对经酸洗、喷砂、激光毛化工艺处理后的钛合金、不锈钢、纯镍金属材料试件,进行外观、粗糙度、微观形貌检测,并在胶接后进行浮辊剥离试验、剪切强度试验,结果表明:激光毛化处理可在金属表面获得规则的微观形貌,且试件无变形现象,与喷砂表面同等级粗糙度下,浮辊剥离值及剪切强度明显高于喷砂或酸洗处理的表面,可有效提升胶接结合强度.     

几种机械表面处理方法对6013铝合金接头胶接性能的影响

采用砂纸打磨、湿喷砂、纳米化等3种机械处理方法对6013铝合金表面进行处理,测试其粘接剪切强度,并与P2化学表面处理方法的结果进行对比。利用SEM、AFM、接触角测量仪等技术对铝合金表面处理前后的表面微观结构、微观粗糙度、润湿性等特性进行了研究。结果表明,不同的表面处理方法对铝合金接头的胶接性能影响不同。湿喷砂和砂纸打磨方法处理后铝合金接头的胶接性能与P2化学法表处的效果接近。纳米化方法不利于铝合金胶接性能的提高。微观粗糙度对铝合金的粘接性能具有重要影响,粗糙度越大,铝板胶接性能越好。润湿性不是影响胶接性能的关键因素。     

P2352W-19预浸料与可剥布匹配性研究

为了进一步了解P2352W-19预浸料匹配可剥布对胶接质量的影响,使用干态和湿态聚酯可剥布处理待胶接表面,并通过Ⅰ型双悬臂梁断裂韧性试验和双搭接剪切试验来考察可剥布处理后试验件的胶接表面力学性能表现,将试验结果结合试验件破坏模式进行分析。研究了层板材料匹配两种高温胶膜的共胶接及二次胶接质量,确定了P2352W-19预浸料最佳匹配可剥布。     

室温固化耐600℃高温有机硅树脂耐热棉毡用胶黏剂

合成了苯梯树脂及耐热黏料树脂,二者以适当的比例配合再添加填料、促进剂、催干剂等来制备一种胶黏剂,并对胶黏剂与钛合金、隔热材料的胶接进行了探索性研究,该胶黏剂是可以室温固化的有机硅树脂胶黏剂,胶黏剂对钛合金与耐热棉毡均有较好的粘接性能,并且制得的胶黏剂在较高温度（650℃）有着较小的热失重,符合了钛合金与隔热材料实际粘接的需求。     

Comparative determination of TiO2 surface free energies for adhesive bonding application

The development of durable bonds using titanium adherens has been investigated from the point of view of surface energy theoretical models measurements. The traditional Chromium Acid Anodization, which provides excellent durability, has to be phased out due to the use of hazardous Cr (VI) in the bath and as a result, special attention is paid to the sodium hydroxide anodizing and other alkaline chemical etchers. There are hardly any references on the surface free energy of adhesive titanium oxide coatings and therefore the objective of this work was to evaluate the surface and interface energy parameters of the various types of alkaline chromate free surface treatments using Neumann, Fowkes and van Oss–Chaudhury–Good methods in order to determine which method provides greatest differentiation between the coatings. Results show that Fowkes method produced the greatest variance in surface energies of the compared surface treatments and hence can be considered as better suited for more accurate discrimination between the oxide surface treatments on Ti–6Al–4V alloy. Although, in the case of model liquids, i.e. water and diiodomethane, the trends obtained for contact angles, surface energies, works of adhesion and solid/liquid interface energies all correlated between each other, a disagreement between the trends of solid/liquid interface energies calculated using Fowkes and van Oss–Chaudhury–Good methods for surface treatment/adhesive resin was obtained. In case of real adhesive systems, the use of work of adhesion appears more adequate in order to discriminate the surface treatments. Based on these findings the anodization in the tested alkaline bath after a previous alkali etching in the same bath is recommended, although adhesion test has to be still performed.     

Strength and bonding characteristics of adhesive joints with surface-treated titanium-alloy substrates

This paper presents a study on the effect of surface treatments on the mechanical behavior of adhesively bonded titanium alloy joints. Several different treatments were selected for the preparation of Ti-6Al-4V alloy faying surfaces, and bonded joints were fabricated using surface-treated titanium alloy substrates and a film adhesive. Tensile tests were performed on single-lap specimens to evaluate the joint strength and to assess the failure mode, i.e. cohesive failure, adhesive (interfacial) failure or a mix of both. Contact angle measurements were also carried out, and the surface free energies of titanium alloys and the thermodynamic works of adhesion for the adhesive/titanium alloy interfaces were obtained. A three-dimensional finite element analysis was used to predict the strength of the specimens exhibiting cohesive failure. In addition, an expression of the relationship between the joint strength corresponding to interfacial failure and the thermodynamic work of adhesion was introduced based on the cohesive zone model (CZM) concept. It is shown that two surface treatments, Itro treatment and Laseridge, lead to cohesive failure and a significant increase in the joint strength, and the numerically predicted strength values are fairly close to the experimental values. These surface treatments are possible replacements for the traditional surface treatment processes. For degreasing, emery paper abrasion, atmospheric plasma treatment, sulfuric acid anodizing, nano adhesion technology and high-power lasershot, the specimens fail at the adhesive/substrate interface and the joint strength increases linearly with the thermodynamic work of adhesion as expected from our CZM-based expression.     

Atmospheric pressure plasma surface modification of titanium for high temperature adhesive bonding

In this investigation surface treatment of titanium is carried out by plasma ion implantation under atmospheric pressure plasma in order to increase the adhesive bond strength. Prior to the plasma treatment, titanium surfaces were mechanically treated by sand blasting. It is observed that the contact angle of de-ionized water decreases with the grit blast treatment time. Optical microscopy and scanning electron microscopic (SEM) analysis of untreated and atmospheric plasma treated titanium are carried out to examine the surface characteristics. A substantial improvement in the surface energy of titanium is observed after the atmospheric pressure plasma treatment. The surface energy increases with increasing exposure time of atmospheric pressure plasma. The optimized time of plasma treatment suggested in this investigation results in maximum adhesive bond strength of the titanium. Unmodified and surface modified titanium sheets by atmospheric pressure plasma were adhesively bonded by high temperature resistant polyimide adhesive. The glass transition temperature of this adhesive is 310 °C and these adhesively bonded joints were cured at high temperature. A substantial improvement in adhesive bond strength was observed after atmospheric pressure plasma treatment.     

Processing study of a high temperature adhesive

An adhesive-bonding process cycle study was performed for a polyimidesulphone. The high molecular weight, linear aromatic system possesses properties which make it attractive as a processable, low-cost material for elevated temperature applications. The results of a study to better understand the parameters that affect the adhesive properties of the polymer for titanium alloy adherends are presented. These include the tape preparation, the use of a primer and press and simulated autoclave processing conditions. The polymer was characterized using Fourier transform infrared spectroscopy, glass transition temperature determination, flow measurements, and weight loss measurements. The lap shear strength of the adhesive was used to evaluate the effects of the bonding process variations.     

钛合金表面防护技术进展

钛合金具有比强度高,中温性能好和耐腐蚀等显著优点,但由于存在抗高温氧化性差、硬度低、易粘着、耐磨性能不佳的缺点,极大限制了合金的应用范围。而表面防护技术是提高合金的整体性能的关键措施,文中综述了目前的防护技术及其优缺点,并指出了今后的研究方向。     

Plasma-sprayed coatings as surface treatments of aluminum and titanium adherends

Plasma-sprayed coatings have been evaluated as surface treatments for aluminum and titanium adherends. The best aluminum treatment is found to be a 50-μm thick blend of an aluminum-12% silicon alloy and polyester with 20-40% polyester. For FM-300M film adhesive, this coating gives a wedge test performance equivalent to phosphoric acid anodization (PAA). For FM-123 film adhesive, its performance is between that of the Forest Products Laboratory (FPL) etch and PAA. The aluminum in the composite coating provides structural strength and adhesion to the substrate; the polyester serves to toughen the coating and perhaps supplement the physical bonding (mechanical interlocking) provided by the microscopically rough morphology with chemical bonding to the adhesive. For titanium, a 50-μm plasma-sprayed Ti-6Al-4V coating provides an identical performance to the best chemical treatment with crack propagation entirely within the adhesive. These plasma-sprayed coatings avoid the disposal and environmental costs of conventional chemical treatments using chromates and strong acids or bases. They are also well suited to repair or refurbishment of existing components.     

Polyimide–silica hybrids containing novel phenylethynyl imide silanes as coupling agents for surface-treated titanium alloy

Polyimide–silica hybrids composed of an organic precursor containing a novel phenylethynyl imide silane and an inorganic precursor were evaluated as an adhesion-promoting interphase between surface-treated titanium alloy and a phenylethynyl-containing imide adhesive. The phenylethynyl groups present in the organic precursor, either as a pendent or end group, can bond chemically with a phenylethynyl-containing imide adhesive during processing, while the silane groups of the organic precursor would react chemically with the inorganic precursor. In addition, the inorganic precursor is able to react with the titanium alloy to form a stable bond with the metal oxide. Bond strength and durability were evaluated by single lap shear tests at various conditions. Lap shear specimens exhibited predominantly cohesive failure after a 3-d water boil with 92% retention of the initial room temperature strength. Morphology and chemical composition of the hybrid interphase were investigated with scanning electron microscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy, which revealed development of a silicon-gradient, hybrid structure between the metal substrate and the adhesive.     

高温下炭/炭复合材料对钛合金组织及性能的影响

将炭／炭复合材料与钛合金紧密接触并进行高温热处理，采用SEM、EDX、光学显微镜和三点弯曲测试，研究其高温热处理后炭／炭复合材料对钛合金组织结构和力学性能的影响。结果表明：炭／炭复合材料与钛合金在高温下几乎不发生反应；炭／炭复合材料中的碳元素未进入钛合金结构中；随热处理温度的升高和时间的延长，钛合金的室温弯曲强度减小，断裂特性由最初的韧性断裂转变为脆性断裂，钛合金的晶相结构中的网篮组织减少，等轴组织增多。