钛合金基体上阻燃涂层的研究进展

介绍了航空发动机上钛燃烧及其原因。概括了国内外钛合金基体上阻燃涂层的研究概况,重点对钛合金基体上阻燃涂层的应用、阻燃性能的检测方法和阻燃机理进行了总结。并对国内该类涂层的研究提出了一些建议。     

Ti40/NiCrAl阻燃涂层抗氧化性能研究

采用等离子喷涂工艺在Ti40基体表面制备厚0.2~0.4mm的阻燃涂层,并利用光学和扫描电子显微镜对钛合金基体和阻燃涂层的显微结构、截面形貌进行表征,开展了钛合金和阻燃涂层在600℃下的抗氧化性能试验研究。结果表明:涂覆阻燃涂层的钛合金试样在600℃静态空气中连续氧化100h后,其氧化增重减少76%以上,氧化速率降低92%,抗高温氧化性能提高12倍;同时,SEM观察结果显示高温氧化后阻燃涂层仍保持完好,说明该涂层与试样的结合性能以及涂层的抗氧化性能较好,适应于航空发动机防钛火阻燃涂层。     

微弧离子沉积阻燃涂层及其性能

采用微弧离子表面改性技术在TC11合金表面制备阻燃涂层,采用扫描电镜、透射电镜、XRD等方法分析了阻燃涂层组织及物相,采用“钛火”液滴法试验平台测试了TC11钛合金在300～700 ℃之间的燃烧参数,验证了同等试验条件下带有阻燃涂层TC11钛合金试样在300～700 ℃之间的阻燃有效性. 结果表明,制备的阻燃涂层主要由TiZr非晶相组成,涂层致密,与基体为冶金结合,700 ℃以内具有一定的阻燃性能,分析阻燃涂层的阻燃机理主要为涂层吸收能量,减小基体对热量的吸收,同时阻止钛合金与氧接触机制来阻燃.     

国内阻燃钛合金工程化技术研究进展

阻燃钛合金的研制是防止"钛火"事故的最直接的方法。美国、英国和俄罗斯等均在积极开展阻燃钛合金的阻燃机理及其工程化技术研究,我国阻燃钛合金的基础研究起步较早,但在工程化技术开发及应用方面停滞多年,导致被发达国家拉开差距。近五年来,在材料研制单位和应用研究单位的共同努力下,Ti-V-Cr系阻燃钛合金工程化技术取得了显著进步。本文主要综述了近几年来国内阻燃钛合金工程化技术研究的最新进展;重点介绍了Ti40和WSTi3515S合金大型铸锭、大棒材及大尺寸板坯和环锻件的研制情况,并介绍了阻燃钛合金机械加工技术和摩擦点燃阻燃性能评价方法,最后对我国阻燃钛合金未来发展进行了展望。     

电火花沉积钛基非晶阻燃涂层及阻燃性能研究

采用电火花沉积技术在Ti40合金表面制备阻燃涂层,采用扫描电镜、EDS、XRD等方法分析了阻燃涂层组织及物相,采用"钛火"液滴法试验平台验证了阻燃涂层阻燃有效性。结果表明:制备的阻燃涂层主要由TiZr非晶组成,涂层致密,无任何孔隙,服役状态下涂层不会发生破裂、鼓泡等现象,可有效阻止氧与钛合金接触,切断了氧与钛合金的反应,达到了阻燃目的。     

医用钛及钛合金表面涂层研究进展

概述了钛及钛合金在医学领域的发展现状,以及常用的钛及钛合金表面处理技术,重点介绍了医用钛及钛合金表面耐蚀耐磨涂层、生物活性涂层和表面抗菌涂层的研究现状和发展趋势。在钛及钛合金表面制备涂层能够使其更适合作为植入物在医学领域应用,但由于涂层自身还存在一定局限性,临床试验也需要大量的时间,目前涂层还没有大规模应用到临床医疗中。为了尽可能地改善单一涂层存在的缺陷,多组元、多层复合涂层是目前医用钛及钛合金表面涂层的研究重点。     

微弧离子沉积阻燃涂层对TC11钛合金力学性能的影响

为使阻燃涂层早日在我国航空发动机上得到应用,在提高涂层阻燃性能的同时,研究涂层对基体力学性能的影响十分必要。文中采用微弧离子表面改性技术在TC11钛合金基体上制备阻燃涂层,研究阻燃涂层对钛合金拉伸性能、压缩性能、蠕变性能及裂纹扩展速率的影响。结果表明,采用微弧离子表面改性技术在TC11基体上制备的阻燃涂层主要由TiC2、W2C及Ti组成,涂层结构致密,与基体结合良好。涂层试样规定非比例延伸强度、抗拉强度以及断面收缩率有轻微降低,降低幅值约为基体抗拉强度5%左右;断后延长率基本无变化,弹性模量随测试温度提高逐步下降,试样抗压强度增大,400℃高温蠕变性能变好,常温裂纹扩展速率降低。综合分析表明,在钛合金基体上制备阻燃涂层后,试样整体力学性能变化幅值小于5%,符合航空发动机部件强度设计要求。     

钛合金表面等离子喷涂涂层材料的研究进展

介绍了钛及钛合金表面等离子喷涂涂层材料的研究进展,主要从钛合金表面等离子喷涂陶瓷材料耐磨涂层、固体润滑减摩涂层、生物活性涂层、功能涂层等几方面进行了简要的介绍。并对钛及钛合金表面等离子喷涂涂层材料的发展趋势进行了展望。     

钛合金叶尖保护涂层的制备与表征

通过对TC4钛合金基体进行表面活化处理,并采用复合电镀技术,在钛合金基体上制备了结合力良好的Ni-c BN复合镀层。研制的复合镀层能够减少航空发动机钛合金叶片叶尖的摩擦磨损、杜绝"钛火"事故。进行了镀层的高温摩擦磨损试验以及与镍基封严涂层的磨削试验,利用扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)等对涂层性能进行表征。结果表明:采用的钛合金基体表面活化处理技术,可保证复合镀层具有良好的结合力;同时,研制的Ni-c BN复合镀层对封严涂层具有良好的磨削能力和较低的摩擦系数,可以有效保护钛合金叶尖。     

磷氮阻燃剂 / 纯丙树脂光固化复合膨胀阻燃涂层制备及膨胀行为

目的制备一种新型磷氮类紫外光固化膨胀阻燃涂层,研究磷氮复合成分对阻燃性能及膨胀行为的影响。方法采用丙烯酸正丁酯、甲基丙烯酸甲酯、甲基丙烯酸缩水甘油酯为原料制备环氧侧基聚丙烯酸酯,进一步利用丙烯酸开环环氧制备光固化聚丙烯酸酯,并结合前期所合成的含磷单体磷杂环丙烯酸酯磷酸酯(PGMH)和含氮光固化单体三嗪基四丙烯酸酯(BDAETH)制备光固化膨胀阻燃涂层。通过热重法和红外光谱研究了PGMH对光固化聚丙烯酸酯固化膜热降解机理的影响。采用极限氧指数对涂层阻燃性能进行研究,设计并自制设备对涂层的膨胀行为进行监测。结果随着磷氮复合阻燃剂的添加,涂层在450~480℃之间快速膨胀,其最大单向膨胀度可达14。膨胀碳层隔绝氧气,从而提升阻燃性能,将光固化聚丙烯酸酯的氧指数从19提升到28.5。结论磷氮复合阻燃剂的添加可有效赋予涂层在升温或燃烧过程中的膨胀特性,生成隔绝氧气的膨胀碳层,提高涂层的阻燃性能。     

防火板阻燃环装配一体机设计

木材建造的住宅具有很好的抗震性能,但木材防火性能差,房屋内需要防火性能好的装修材料。设计一台防火板阻燃环装配一体机,用于新型室内防火装饰板制作。防火板在两轴联动工作台上定位,多轴钻自动完成钻孔;阻燃环坯料自动进给并被飞刀切割成规定长度;阻燃环落入送料托盘凹槽中,送料托盘X轴精确位移将阻燃环送到装配位置;挤压冲头将阻燃环压入阶梯孔;托盘与工作台联动可完成所有阻燃环安装。该机可完成防火板钻孔、切割和装配阻燃环等工序,具有自动化程度高、工作效率高等优点,但由于联动部件多、机械结构复杂,尚需优化结构、降低成本、提高整机工作可靠性。     

Oxidation of double glow plasma discharge coatings of iridium on molybdenum for liquid fuelled rocket motor casings

Abstract

Dense and uniform coatings of iridium (Ir), 5–7 μm in thickness, were deposited onto molybdenum (Mo) substrates by double glow plasma discharge in the temperature range of 800–850°C at 35 Pa. During deposition, the Mo substrate was biased at a voltage of ?300 V while the 99·9% Ir target was at a bias voltage of ?800 V. After deposition, the Ir coating was ablated using an oxyacetylene torch with a flame temperature of ～2000°C to determine the high temperature stability of the coated substrate. The morphology and microstructure of the Ir coating were observed using scanning electron microscopy while the composition and structure were measured using X-ray diffraction and energy dispersive spectroscopy. The thickness of the as deposited Ir coating was uniform and the interface between the coating and the substrate exhibited excellent adhesion with no evidence of delamination and cracks. After exposure to the flame, the surface of the as ablated coating presented imperfections including pores, bulges and cracks; however, the Ir coating retained sufficient adhesion to limit the weight loss of the Ir coated Mo substrate to 10 mg cm^?2 s^?1.     

BSC-GT系列电缆、钢结构防火涂料的研制、性能和应用

文章扼要介绍了BSC-GT系列电缆钢结构防火涂料的选材要求、产品的灭火机理,主要技术指标与应用。     

Living radical polymerization and grafting of diethyl (acryloyloxy) ethylthiophosphoramidate onto cotton fabric to impart flame retardancy

A novel phosphorus, nitrogen and sulfur containing monomer, diethyl (acryloyloxy) ethylthiophosphoramidate was synthesized in a two step reaction. The monomer was polymerized and grafted onto cotton fabric by the living radical polymerization method using benzyl N,N-diethyl thiocarbamate as iniferter and sur-iniferter respectively. The monomer, its precursor, iniferter and the polymer were characterized by spectroscopic techniques. Flame retardant property of the modified cotton fabric was studied by the Shirley Manual Flammability Tester and it was found that the incorporation of phosphorus and nitrogen together exerts a synergistic effect in imparting flame retarding property to the fabric.     

Towards multifunctional surfaces using the plasma-induced graft-polymerization (PIGP) process: Flame and waterproof cotton textiles

In order to produce multifunctional surfaces, water-repellent treatment combined with fire retardant finishes on cotton fabrics have been investigated by using the cold plasma technique. Three different protocols involving Ar plasma-induced graft-polymerization (PIGP) of flame retardant monomers (acrylate phosphate and phosphonates derivatives) combined to a water-repellent treatment - CF₄ plasma treatment or Ar plasma induced graft polymerization of 1,1,2,2, tetrahydroperfluorodecylacrylate (AC8) - are proposed.The Limiting Oxygen Indices (LOI) and Schmerber pressures (P_Sch.) were measured to evaluate the flame retardant and the water-repellent character, respectively. The obtained results have shown that for each protocol the flame retardant monomers investigated (DEAEP, DEAEPN) were compatible with a water-repellent treatment.     

火焰喷涂尼龙1010/纳米ZnO复合涂层性能研究

为了探讨纳米ZnO(n- ZnO)对火焰喷涂尼龙1010涂层力学及抗老化性能的影响,利用电子拉力机和紫外光辐照箱对火焰喷涂尼龙1010/n- ZnO复合涂层的力学性能及耐老化性能进行了测试.结果表明,当复合涂层配比为m(PA1010):m(n- ZnO)=100: 1.5时,复合涂层综合性能较佳,涂层自拉伸强度为41.92MPa;涂层与基体结合强度为41.68 MPa;涂层经10天紫外线老化后,强度保持率分别为97%和87.2%.纳米ZnO能够显著提高涂层力学性能和抗老化性能.     

FeBSiNb合金粉末制备及非晶涂层性能研究

采用气雾化制备了FeBSiNb合金粉末,经过火焰喷涂后,制备了高非晶含量的FeBSiNb涂层。利用X射线衍射仪、差热分析仪、扫描电镜和透射电镜分析了粉末和涂层的表面形貌、显微组织和结构特征。结果表明：FeBSiNb合金粉末主要由晶体Fe₂B相和α-Fe(Si)固溶体组成。FeBSiNb非晶涂层主要由非晶相(含量85vol%左右)、Fe₂B晶体相和α-Fe(Si)纳米晶相组成。非晶涂层在531~605℃区间发生晶化,涂层的玻璃转变温度T_g为513℃,晶化温度T_x为531℃,计算得出FeBSiNb系合金形成非晶相的临界冷却速率在2.0×10₆ K/s左右。对涂层的摩擦磨损性能进行测试,在5N,5Hz,30min摩擦条件下,FeBSiNb非晶涂层的摩擦系数仅为0.2左右,相对耐磨性约为45_#钢基体的10倍。     

Flame spraying of coatings of self-fluxing alloys

Currently available methods and equipment for powder flame spraying coatings of self-fluxing alloys are analysed. The analysis results are used to develop a new process, continuous flame spraying of coatings and equipment for this method. In this method, the preheating of the surface to be sprayed, deposition of the coating layer and its melting are carried out simultaneously using the same flame equipment with higher power without breaks between the operations. Examples of new possibilities of industrial application of flame spraying of coatings of self-fluxing alloys for hardening and reconditioning components for different applications are described.     

Improvement of flame spraying PEEK coating characteristics using lasers

Flame spraying is frequently used for PEEK coatings elaboration on metallic surfaces. However, this process has a certain number of limitations particularly considering the quality of the coatings like high porosity or low interfacial adherence. For that reason a thermal post-processing is often necessary. From all of the processes which can be used (flame, oven, etc.), laser can be an interesting technology. Then, the aim of this study is to analyse the dependence of the morphological structure (compactness) and the adherence of the flame sprayed PEEK coatings to the stainless steel (304L) and aluminium alloy (AA2017) substrates on laser parameters. Moreover, the influence of the laser beam wavelength (by using a Nd:YAG, CO₂ or diode lasers) on compactness of the coating was analysed. Whatever the laser used, it consists to estimate the most optimized parameters to achieve melting without burning the PEEK material.