含氮聚硅氧烷配位体及其Cu^2＋络合物的介电性能

研究了ｎ－β（氨乙基）－γ（氨丙基）三乙氧基硅烷（ＮＨ２（ＣＨ２）２ＮＨ（ＣＨ２）３Ｓｉ（ＯＥｔ）３）与二甲基二乙氧基硅烷（ＣＨ３）２Ｓｉ（ＯＥｔ）２）共水解，制备含（ＣＨ２）３ＮＨ（ＣＨ２）２ＮＨ２功能基的聚硅氧烷配位体，用ＩＲ，＾１ＨＮＭＲ和元素分析法对水解产物分析证明，ＮＨ２（ＣＨ２）２ＮＨ（ＣＨ２）３Ｓｉ（ＯＥｔ）３与（ＣＨ３）２Ｓｉ（ＯＥｔ）２进行了共水解反应，而且水解程度随ＮＨ２（ＣＨ     

多孔陶瓷薄膜表面形貌研究

用原子力显微镜（ＡＦＭ）观察Ａｌ２Ｏ３、Ａｌ２Ｏ３－ＳｉＯ２及Ａｌ２Ｏ３－ＳｉＯ２－ＴｉＯ２复合陶瓷薄膜的表面形貌,Ｘ射线衍射（ＸＲＤ）分析表明,Ａｌ２Ｏ３薄膜的上为γ－Ａｌ２Ｏ３;Ａｌ２Ｏ３－ＳｉＯ２薄由γ－Ａｌ２Ｏ３和非晶诚ＳｉＯ２组成;而Ａｌ２Ｏ３－ＳｉＯ２－ＴｉＯ２薄膜的相成分为Ａｌ２Ｏ３、ＴｉＯ２、Ａｌ４Ｔｉ２ＳｉＯ１２和非晶态ＳｉＯ２,各相的含量随化学成分变化而变化,ＡＦＭ观察结果表明     

富碳含钛碳化硅纤维的研制

以聚硅烷（ＰＳ）,聚氯乙烯（ＰＶＣ）和钛酸四丁酯（Ｔｉ（ＯＢｕ）４）合成含碳量不同的聚钛碳硅烷（ＰＴＣ）先驱体,经熔融纺丝、不熔化处理、高温烧成制备出具有较好工艺性能和电阻率为１０＾３Ω．ｃｍ～１０＾０Ω．ｃｍ的富碳含钛碳化硅纤维（Ｓｉ－Ｔｉ－Ｃ－Ｏ纤维）。运用ＩＲ、ＧＰＣ、ＶＰＯ待分析手段系统地研究了富碳ＰＴＣ先驱体的合成,讨论了含碳量对纤维的制备工艺及纤维性能的影响。     

涂层对TI纤维与Ti／TiAl复合材料性能影响的研究

研究了涂层对Ｔｉ纤维及Ｔｉ纤维强化γ－ＴｉＡｌ金属间化合物基复合材料性能的影响。研究结果表明，运用物理气相沉积法（ＰＶＤ）在Ｔｉ纤维表面涂覆Ｙ２Ｏ３制得Ｔｉ／ＴｉＡｌ复合材料，不仅改善了γ－ＴｉＡｌ及其复合材料的力学性能，而且使纤维与基体间的界面反应层厚度减小，涂覆Ｙ２Ｏ３较Ａｌ２Ｏ３有较高的稳定性，这对深入研究涂层对复合材料合成及性能的影响有着重要的意义。     

电阻率可调的Si—Ti—C—O纤维的研制

以Ｔｉ（ＯＢｕ）４与低分子量聚硅烷为原料合成不同含钛量的聚钛碳硅烷,经熔融纺丝、空气不熔化及高温烧结等工艺,制备出了电阻率为１０６～１０３Ω·ｃｍ的Ｓｉ－Ｔｉ－Ｃ－Ｏ纤维。通过ＩＲ、ＧＰＣ、ＶＰＯ、ＸＰＳ等分析手段,系统地研究了钛含量对纤维的制备、结构及其电性能的影响     

等离子喷涂A12O3＋13%TiO2陶瓷涂层的组织结构及其耐磨性

本文用Ｘ射线衍射、扫描电镜等研究了等离子喷涂Ａ１２Ｏ３＋１３％ＴｉＯ２（质量分数）陶瓷涂层的相结构、相组成及其组织特征。陶瓷涂层孔隙率低,致密程度较高,以亚稳相ｒ－Ａ１２Ｏ３为主要相,同时存在α－Ａ１２Ｏ３和金红石ＴｉＯ２。富Ａ１２Ｏ３区与富ＴｉＯ２区呈明显相互交迭的层状结构,且存在相互成分扩散,另外涂层设计对硬度有一定影响,ＴｉＯ２的引入提高了涂层的耐磨性。     

涂层成分对IrO_2（5）TiO_2（60）Co_3O_4（x）RuO_2（35

用电化学和Ｘ射线衍射方法研究了氧化物涂层成分对热分解法制备的ＩｒＯ２（５）ＴｉＯ２（６０）Ｃｏ３Ｏ４（ｘ）ＲｕＯ２（３５—ｘ）／Ｔｉ阳极材料析氯速率的影响．ｘ值为０－１３ｍ／ｏ时，氧化物涂层为单相金红石型固溶体，阳极析氯速率随ｘ值增加，ｘ值大于１３ｍ／ｏ时，涂层中出现尖晶石Ｃｏ３Ｏ４第二相，析氯速率随ｘ值下降．     

（CF_3SO_3）_3Al引发的1，3－戊二烯－苯乙烯阳离子共聚合

以三氟甲基磺酸铝（ＣＦ_３ＳＯ_３）_３Ａｌ为引发剂，正己烷为溶剂，通过阳离子聚合，合成了１，３－戊二烯－苯乙烯共聚物。用ＩＲ、￣１ＨＮＭＲ对共聚物结构进行了分析，并用ＳＥＣ（ＧＰＣ）对共聚物分子量进行了表征，对共聚物的环化度也进行了研究，用Ｋｅｌｅｎ－Ｔｕｄｏｓ方法测定的共聚合反应体系苯乙烯（Ｍ_１）和１，３－戊二烯（Ｍ_２）的竞聚率分别为γ_１＝２．１，γ_２＝０．６。     

涂层结构设计对等离子喷涂陶瓷层结合强度及莫应力的影响

用等离子在４５＃碳钢上喷涂了不同涂层设计的Ａｌ２Ｏ３以及Ａｌ２Ｏ３＋１３０ｍｇ·ｇ－１ＴｉＯ２陶瓷层．用Ｘ－射线衍射法和拉伸实验测量了涂层表面层中的残余应力及结合强度．增加粘结层和过渡层能大大地克服陶瓷涂层与基材机械的以及热的不匹配性，使涂层的应力和结合强度都得到明显改善．此外，ＳｉＯ２能改善ＺｒＯ２陶瓷层与基材以及陶瓷层内部的结合程度，使涂层内应力松弛并使其结合强度提高．然而ＳｉＯ２添加剂只有在高熔点陶瓷层中（如ＺｒＯ２），＂液相烧结＂作用才明显，而在熔点较低的陶瓷层中（如Ａｌ２Ｏ３），这种作用并不明显．在用等离子喷涂低熔点Ａｌ２Ｏ３陶瓷时，添加适量的低熔点ＴｉＯ２陶瓷是必要的．     

溶胶—凝胶法制备有机改性SiO2—TiO2涂层的研究

用溶胶－凝胶法在ＰＭＭＡ上制得ＳｉＯ２－ＴｉＯ２涂层。溶胶粘度分析表明，溶胶以线性生长方式凝胶，适宜于制备薄膜。ＦＴＩＲ对涂层的干燥和热处理过程研究表明，涂层中形成Ｓｉ－Ｏ－Ｔｉ－Ｏ－Ｓｉ无机网络结构。扫描电镜对涂层中Ｔｉ－Ｓｉ元素的分布进行了能谱分析，发现无机网络主要分布于涂层的表面及界面处。     

正硅酸乙酯为无机组分前驱体的聚碳酸酯耐磨涂层

以正硅酸乙酯(TEOS)作为无机组分的前驱体,甲基三甲氧基硅烷(MTMS)水解聚合产物作为有机组分,通过溶胶-凝胶法在聚碳酸酯(PC)表面形成耐磨涂层。红外光谱分析表明该涂层具有Si—O—Si的交联网络结构。研究了MTMS和TEOS的摩尔比对涂层的光学性能、硬度、附着力和耐磨性能的影响。结果表明,当MTMS和TEOS的摩尔比为2∶1时,涂层的综合性能达到最优,该涂层在经历500次耐磨试验后的雾度为12.69%,而纯PC的雾度增至42.38%。采用SEM和TEM分析了MTMS/TEOS具有优异耐磨性能的原因在于该涂层具有纳米SiO2粒子分散于有机基体的微观结构。     

Nickel-based wear-resistant coatings by vacuum melting

In various coating processes nickel-based hard alloy powders are applied in either an atomized or a mechanically pulverized form. The coatings show good corrosion resistance, a high abrasion resistance and a relatively low melting point. Since boron is sparingly soluble in nickel, the boride Ni₃B forms a low melting eutectic at about 1000 °C with the nickel solid solution. Boron and silicon act simultaneously as deoxidizers and improve both the properties of the coating and the bonding to the substrate. Diffusion into the substrate occurs during the coating procedures.In this paper we discuss the behaviour of heterogeneous powder compounds with nickel hard alloys. For many applications mixtures with various carbides are used. During coating, reactions take place between the Ni-Cr matrix and the added carbides. These heterogeneous or quasi-alloys, which are used because of their abrasion resistance, are metastable.The abrasion resistance depends primarily on the phases as well as on their grain size, the grain size distribution and alterations to the matrix. When carbidic quasi-alloys are exposed to abrasion and corrosion at high temperatures, reactions of the existing phases during use cannot be completely excluded. Heat treatment causes changes in the structure and abrasion resistance of carbide-containing quasi-alloys.It is difficult to follow reactions which take place during coating either in the fused mass of quasi-alloys or in heterogeneous compounds. Because of their relatively low melting points nickel-based hard alloys can be coated by furnace melting. Hence carbide compounds with Ni-Cr-B-Si powder alloys are most suitable for research also. In these mechanical alloys segregation, of relevance to practical applications, can be studied as well as the formation of various phases during the coating or heat treatment processes.The behaviour of mixtures of Ni-Cr-B-Si powder alloy with different amounts of a number of carbides is reported. The structures of the resulting phases were studied and we tried to correlate these with the results of our abrasion tests.For tungsten carbide-nickel hard alloy mixtures the formation of the ? phase is influenced by the coating parameters and the matrix as well as by the diffusion of iron from the substrate into the coating.We also investigated mixtures of an Ni-Cr-B-Si matrix with TiC (Ti, W)C and NbC. The wear resistance against steel and SiC was measured. Various wear mechanisms and the properties of the carbide-matrix interface the wear results.     

激光熔覆Al-Ni-TiC-CeO2复合涂层的组织与耐腐蚀磨损性能

采用激光熔覆技术在S355海洋钢表面制备Al-Ni-TiC-CeO2熔覆涂层,通过SEM、EDS、XRD、显微硬度计等手段分析其表面-界面形貌、化学元素分布、物相组成及显微硬度,并研究其在3.5%(质量分数)NaCl溶液中耐腐蚀磨损与应力腐蚀开裂(stress corrosion cracking,SCC)等性能。结果表明:熔覆涂层主要由增强相TiC和连续相AlNi3,AlFe3组成,表面较为平整,无明显裂纹,稀释率为5%。涂层表面显微硬度达到809.3HV0.2,为基体的2.3倍。基体中交互作用主要以腐蚀加速磨损为主,而涂层中交互作用则以磨损加速腐蚀为主。基体材料与涂层的SCC敏感性分别为35.01%和17.69%,表明涂层能够明显抑制应力腐蚀开裂。     

TA15合金表面Ni-SiC复合镀层的摩擦磨损性能

采用共沉积法在TA15合金表面制备了Ni-SiC复合镀层, 分析了Ni-SiC复合镀层对基体合金硬度和磨擦磨损性能的影响, 并对其摩擦磨损机制进行了讨论。结果表明: 所制备的Ni-SiC复合镀层组织致密且与基体结合紧密, 硬度明显高于TA15合金基体。摩擦磨损实验结果表明, Ni-SiC复合镀层能为TA15合金提供良好的摩擦磨损抗力, 在相同的摩擦条件下, Ni-SiC复合镀层的磨损率明显低于TA15合金。TA15合金与GCr15球和Al₂O₃球对磨的磨损机制均主要为犁削磨损、粘着磨损, 同时伴随有氧化磨损和轻微的磨粒磨损; Ni-SiC复合镀层与GCr15磨球对磨的磨损机制主要为镀层组织的拔出及GCr15钢球在其表面上的涂抹, 与Al₂O₃磨球对磨时的磨损机制主要为疲劳磨损和削层磨损。     

氩弧熔覆Fe-Al金属间化合物复合涂层的组织与性能

为改善Fe-Al金属间化合物的力学性能及抗高温氧化性能,利用氩弧熔覆方法在Q235钢上制备了Fe-Al熔覆层和Fe-Al/Al_2O_3熔覆层。采用金相显微镜、X射线衍射仪、硬度计、磨粒磨损试验机对氩弧熔覆涂层进行显微组织结构观察和磨损性能测试。采用高温氧化试验对涂层的耐高温氧化性进行了研究。结果表明:Fe-Al熔覆层形成FeAl和Fe_3Al相,而Fe-Al/Al_2O_3熔覆涂层含有FeAl、Fe_3Al和Al_2O_3相;熔覆层的耐磨粒磨损性能优于基体且Fe-Al/Al_2O_3熔覆层优于Fe-Al熔覆层;熔覆层的耐高温氧化性能明显提高,在700℃下,Fe-Al熔覆层和Fe-Al/Al_2O_3熔覆层相比于基体分别提高了4.46和5.68倍。     

Friction and wear reduction with tribological coatings

The basic requirements for a good tribological surface are (1) low sliding friction, (2) good resistance to scuffing, wear and abrasion, (3) long contact fatigue life and (4) adequate subsurface strength to provide dimensional stability. Coatings have inherent deficiencies. The major problem is failure at the interface between the coating and the substrate, which results in flaking, peeling or spalling of the coating under the repetitively applied contact stresses.Three types of coatings which employ different mechanisms to improve the tribological properties and to maintain coating integrity are described in this paper. Nitrocarburizing represents a class of coatings in which the elements are allowed to diffuse into the surface of the structural material to form an alloy with the substrate. Diffusion provides compositional gradients which result in hard wear-resistant surface and which at low shear strengths avoid the interfaces that frequently exist between coatings and substrates. Chemically vapor-deposited chromium and titanium carbides represent a class of coatings in which a chemically distinct layer is grown on top of the substrate and is bonded to the substrate by diffusion. In the third type of coating, hard particles are suspended in a soft matrix. The hard particles provide the wear and abrasion resistance and the soft matrix both bonds the particles together and provides the low friction. Although the bond strength of this coating to the substrate is lower than that provided by diffusion in the other coatings, the soft matrix will yield without flaking under the shear stresses which are developed at the interface.     

Bioactive composite gradient coatings of nano-hydroxyapatite/polyamide66 fabricated on polyamide66 substrates

Tightly bonding of bioactive coating is the first crucial need for orthopaedic implants. This study describes a novel and convenient technique to prepare bioactive coating with high adhesion on orthopaedic substitutes made of polymeric matrix. Here, a chemical corrosion method has been adopted to fabricate a coating on the surface of injection-moulded polyamide66 (PA66) substrates by corrosive nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite slurry. Scanning electron microscopy observation shows that a porous chemical corrosion region presents between the coating and dense PA66 substrate. Energy-dispersive X-ray spectroscopy analysis indicates that the chemical corrosion region is mainly composed of PA66 matrix, and the coating layer is an n-HA-rich layer. Both the pore size and n-HA composition increase gradually from the polymeric substrate towards the coating surface. Mechanical testing shows the bonding strength can reach 13.7 ± 0.2 MPa, which is much higher than that fabricated on polymeric matrix by other coating methods. The gradual transition in coating structure and composition benefits for the interface bonding and for the surface bone-bonding bioactivity. Subsequent cell experiments corroborate n-HA-rich coating and a porous structure is benefitting for cell attachment and proliferation. The convenient coating method could be popularized and applied on similar polymer implants to produce a tightly and porous bioactive coating for bone tissue regeneration.     

Design of multilayer polymeric coatings for indentation resistance

Summary Indentation is often a mode of in-service loading for a thin coating deposited on a substrate. Under such a loading, the strong adherence of the coating to the substrate is a basic necessity for successful performance of the coating. In this study, we investigate the indentation behavior of thin single and multilayered polymeric coatings using the finite element method. The deformation patterns and the stress fields that are generated during indentation are obtained by employing constitutive models which accurately represent the elastic-viscoplastic and hyperelastic behavior of the glassy and rubbery states of the polymeric layers under investigation. Three types of loading conditions are considered: indentation to (1) a fixed depth; (2) a fixed work; and (3) a fixed force. For these loading conditions, we then investigate the mechanical performance of various composite coatings subjected to an overall thickness design constraint. The composite structure is altered via variation in individual layer material composition, layer thickness and layer arrangement. It is shown how the placement of different material layers in a multilayer coating can alter the flow pattern and hence the distribution of stress state and resulting failure. It is also shown that a soft rubber elastic layer acts to greatly minimize the interfacial shear stress at the substrate, thereby reducing the risk of delamination of the coating, but the presence of the rubber can also produce detrimental tensile stresses on the surface. We then demonstrate that the tensile stress state can be eliminated through manipulation of the rubber layer thickness, without increasing the interface shear stress. Through these examples, a framework for evaluation and design of multilayer coatings for indentation resistance is provided.     

金属表面复合保护涂层的制备与性能研究

采用溶胶-凝胶法合成了有机-无机复合溶胶。用提拉法将复合溶胶涂覆在不锈钢基板上，基板上的湿凝胶经热处理后便形成了透明保护涂层。对制备好的涂层进行了附着力和硬度等性能分析，分析结果表明：有机-无机复合溶胶易于成膜，且成膜具有很好的耐磨性、韧性和耐腐蚀性。     

Scratch resistant optical coatings on polymers by magnetron-plasma-enhanced chemical vapor deposition

The magnetron-plasma-enhanced chemical vapor deposition (magPECVD) provides silicon-organic thin films for optical, electrically insulating or diffusion barrier coating applications. With process pressures of ≤ 1 Pa this technology is well adapted to the sputtering process of optical interference coatings and also facilitates an inline-process implementation. This paper describes the deposition process for scratch resistant coatings on polycarbonate (PC) and allyl diglycol carbonate substrates. Based on the optical, chemical and mechanical characterization of single magPECVD thin films of varied chemical composition, several types of layer stacks (e.g. of gradient or alternating hardness distribution) were deposited with varied total thickness on PC substrates. Abrasion test results indicate two main effects: the resistance against scratches of high load abrasion (50 N) mainly depends on the total coating thickness. The durability against scratches of low load abrasion (5 N) shows a clear advantage for the multilayer design in contrast to homogeneous single layers even of higher thickness. Finally a 5-layer antireflective system was reactively sputtered onto the magPECVD coating and successfully passed adhesion and environmental tests.