环氧胶粘纳米涂层冲蚀磨损性能研究

向环氧树脂胶粘涂层中分别加入粉煤灰、纳米SiO2,通过改变磨料的粒度和含量,冲蚀的转角和转速,研究其耐冲蚀磨损性能。通过实验推荐了具有较好耐冲蚀能力的环氧树脂的最佳配方。     

涂层磨损测试方法与环氧树脂耐蚀磨性能研究

研究了磨损测试方法和环氧树脂胶粘涂层的耐冲蚀磨损性能。通过添加不同填料并与固化剂反应制得了不同环氧树脂试样。试验表明:在攻角(入射角)45°时冲蚀率最大,攻角60°时冲蚀率最小。而随冲蚀速度增加,冲蚀率显著增大。加入纳米蒙脱土填料的环氧胶粘涂料比普通复合材料具有良好的抗冲蚀磨损性能。     

纳米环氧树脂复合涂层耐冲蚀磨损性能研究

研究了固化剂低分子聚酰胺、有机蒙脱土和纳米Al2O3的用量对环氧树脂胶粘涂层拉伸剪切强度和耐冲蚀磨损性能的影响。试验表明,有机蒙脱土和纳米Al2O3能有效提高涂层拉伸剪切强度和耐冲蚀磨损性能,在最佳配方下,涂层的耐冲蚀磨损性能是Q235钢的10.83倍。     

纳米填料对环氧胶粘涂层冲蚀磨损性能的影响

在环氧胶粘涂层中加入填料可提高其强度和耐磨性。研究了转角、转速对填料分别为纳米SiO2、粉煤灰的环氧树脂涂层冲蚀磨损性能的影响。通过实验推荐了具有较好耐冲蚀能力的环氧树脂胶粘涂层的最佳配方。     

等离子喷涂纳米WC—Co涂层高温摩擦磨损性能

本文采用等离子喷涂的方法制备了纳米WC—Co涂层以及超细WC—Co涂层,研究了涂层的高温摩擦磨损性能及失效机理。研究表明,在高温磨损情况下,纳米涂层的综合耐磨损性能明显优于超细涂层。超细涂层和纳米涂层的磨损机理不同,超细涂层以脆性断裂和粘着磨损为主,伴随有磨粒磨损,纳米涂层以韧性断裂和磨粒磨损为主,伴随有粘着磨损。     

AZ31镁合金表面防腐胶粘涂层的研制

胶粘涂层法是有效提高镁合金耐腐蚀性能的表面处理技术之一.以E-44环氧树脂、低分子量650#聚酰胺、云母氧化铁等为主要原料,制备了适用于AZ3l镁合金基体的防腐胶粘涂层.研究了填料含量对涂层外观、施工性和耐蚀性能的影响.结果发现,当填料质量分数为60%、涂层厚度为180～220μm时,防腐胶粘涂层具有良好的外观及施工性,附着力为1级,耐盐雾时间168 h.     

核电厂小尺寸阀门内壁新型冲蚀减缓技术的研发应用

以WCB钢为基材,采用国产化小型超音速火焰喷涂(HVOF)设备喷涂Ni60镍基合金涂层.通过扫描电子显微镜(SEM)及能谱仪(EDS)分析、显微硬度计测试、拉伸试验、磨粒磨损试验和冲蚀磨损试验,考察了Ni60涂层的组织形貌、微观结构、孔隙率、显微硬度、结合强度、耐磨粒磨损性能和耐冲蚀磨损性能,并对实际小尺寸疏水阀门内壁进行喷涂,分析该工艺的实际可行性.结果表明,所制备的Ni60涂层的孔隙率为(0.27±0.04)％,显微硬度为843 HV(载荷300 g),界面结合强度高达200 MPa以上.该涂层主要由弥散分布着碳化物等硬质相的Ni基固溶体组成,具有比WCB基材更优良的耐磨粒磨损和耐冲蚀性能,其冲蚀失效形式主要为犁沟加塑形变形.小尺寸阀门内壁经喷涂后,表面涂层质量及配合性均符合要求.     

环氧树脂涂层的耐冲蚀磨损性能

配制了3种环氧树脂涂层配方,测试其耐冲蚀磨损性能。结果发现,以纳米蒙脱土为填料、203#聚酰胺为固化剂的环氧树脂涂层的耐冲蚀磨损性能最佳:随着磨料粒度、磨料质量分数、试验机主轴转速的增大,冲蚀磨损率增加,攻角为45°时冲蚀磨损率最大,60°时最小;推荐最佳耐磨涂层的配方为:w(环氧树脂E-44):w(环氧树脂E一51):w(203#聚酰胺):w(纳米蒙脱土)为30:70:80:7。     

环氧树脂基复合涂层摩擦磨损性能研究

研究了不同质量分数石墨、碳纤维、纳米ZrO2对环氧树脂(EP)涂层摩擦磨损性能的影响,并用扫描电子显微镜观察了涂层磨损表面形貌并探讨了磨损机理。结果表明:石墨质量分数为20%时复合涂层的磨损率仅为纯EP的7.75%;纳米ZrO2质量分数为4%时复合涂层的磨损率为纯EP的30%;纳米ZrO2与碳纤维以及石墨的协同作用提高了EP的摩擦磨损性能。EP复合涂层的磨损机理以粘着磨损、磨粒磨损以及疲劳磨损为主。     

环氧胶粘涂层冲蚀磨损特性研究

研究了环氧胶粘涂层在不同的磨料粒度和浆体浓度下冲蚀磨损时耐磨性能的变化,对比了T-31、低分子聚酰胺两种固化剂和粉煤灰、有机蒙脱土两种填料对环氧胶粘涂层性能的影响,探讨了纳米粒子在环氧胶粘涂层中的作用,推荐了纳米环氧胶粘涂层的最佳配方。     

Epoxy coatings with modified montmorillonites

Two types of modified layered aluminosilicates (montmorillonites) with different grain size and gallery spaces were tested as nanofillers in epoxy coating compositions for a steel substrate. Organophilic montmorillonites, in the amount of 2.5 and 5 wt% were introduced to waterborne and to solvent-type epoxy coating materials (based on bisphenol-A epoxy resins and various curing agents). The results of this work indicate that processing properties of coating compositions (leveling and drying time) as well as mechanical properties of coatings (hardness, scratch and abrasion resistance, adhesion to steel) were positively affected by a layered aluminosilicate nanofiller. Enhanced water resistance (lower water absorbance) of coats, especially those formed from waterborne compositions, has been found.     

无溶剂液体环氧涂层耐磨性的研究

通过对无溶剂液体环氧涂层耐磨性的研究,验证了影响环氧涂层耐磨性的主要因素是耐磨填料、固化剂种类和涂层的固化程度。     

喷涂聚脲弹性体技术在卡车耐磨衬里中的应用

介绍了喷涂聚脲弹性体(SPUA)技术用于卡车耐磨衬里的优点,重点介绍了SPUA替代高固体分环氧涂料在卡车耐磨衬里中的施工工艺及应用,并对该技术在国内外的应用前景进行了展望.     

新型环氧硅酸酯防腐涂料的研制

将环氧树脂和硅酸酯预聚物通过催化缩合反应,制得环氧硅酸酯涂料,兼有有机和无机涂料的优点,具有高硬度、高耐磨、高附着力、优异的抗渗性、抗溶剂溶胀、抗介质氧化等性能。本文介绍了环氧硅酸酯树脂的合成以及环氧硅酸酯新型防腐涂料的制备。     

Investigation of coating failure on the surface of a water ballast tank of an oil tanker

The current crude oil tanker is constructed as a double-hull structure which consists of an oil tank and a water ballast tank whose surface is coated with epoxy paint to prevent corrosion. Since the cracks that developed in the epoxy coating have caused corrosion of the interface of the water ballast tank, the identification of the parameters for crack development is important. In addition, the moisture absorption by the epoxy coating can cause deterioration of bond strength, which results in delamination of the coating and accelerates the corrosion at the interface. In this study, after the mechanical and thermo-mechanical properties of epoxy paints were measured, the residual stresses induced by the temperature change and cure shrinkage were calculated by the finite element analysis, which were compared with the experimental results. Also, the pull-off tests were performed to investigate the deterioration of the bond strength of epoxy coatings due to moisture absorption. It was found that the thermo-mechanical properties such as the coefficient of thermal expansion and glass transition temperature of the coating materials had dominant effects on the crack resistance rather than the cure shrinkage; the moisture penetration to the bonding interface caused interfacial failure and a significant deterioration of bond strength.     

Investigations on the mechanical properties of hybrid nanocomposite hard coatings on polycarbonate

Hybrid nanocomposite coatings derived from titanium tetraisopropoxide and epoxy or acrylic modified silanes were deposited on polycarbonate (PC) by dip coating employing various withdrawal speeds followed by ultraviolet and thermal curing. The effect of different organic functional groups in the precursors and ageing effect of these sols were systematically studied with respect to thickness, abrasion resistance, pencil scratch test, nanoindentation hardness and transmittance. The gels derived from the freshly prepared and aged sols were structurally characterized by FT-IR and TEM analysis. The viscosities of the sols were monitored with time. The change in viscosity is rapid for sol from epoxy modified silane. The thickness of the coatings increases with increase in viscosity in case of both the silane precursors. The scratch as well as abrasion resistance increases as a function of coating thickness. The pencil scratch hardness improves from 2B for the bare PC to a maximum of 3H for the coating obtained from an aged sol derived from epoxy modified silane. Also, the abrasion resistance of the coatings from same sol was maximum as evidenced by a <6% change in haze after 500 cycles, vis-a-vis 40% for the bare PC. The coatings from a freshly prepared sol of acrylic modified silane and titania showed the maximum nanoindentation hardness of 0.52 GPa, when compared to 0.23 GPa for the bare PC.     

Strengthen adhesion between zirconia and resin cement using different surface modifications

The aim of this research was to assess the influence of different surface modifications on the bond strength between resin cement and zirconia ceramics. Eighty-four zirconium samples were prepared. Four different surface treatments were applied; nano-alumina coating, 2 minutes gas-phase fluorination, 50 μm alumina airborne-particle abrasion, and 50 μm airborne-particle abrasion + 2 minutes gas-phase fluorination. Then specimens were bonded to resin cement. Half of the samples were then incubated in 37°C distilled water for 24 hours. The remaining samples were subjected to thermocycling for 5000 cycles. Shear-bond strength testing was applied at a cross head speed of 5 mm/s. Two-way ANOVA was used in comparison between groups. There is a significant difference between the groups with 5000 cycles and the groups with 24 hours of water cycling. The highest shear-bond strength values were observed in the groups with airborne-particle abrasion + 2 minutes fluorination (27.57 MPa) and nano-alumina coating (26.45 MPa) which were not subjected to thermal cycling. Nano-alumina coating of the zirconia surface and the 2 minutes gas-phase fluorination method following airborne-particle abrasion process increased bond strength between resin cement and zirconia.     

Increase of adhesive bond strength through the mechanochemical creation of free radicals: I

A new technique for improving the strength of bonded joints between various materials and different adhesives is described. Increased strength was obtained by mechanical Surface Activation Beneath Reactive Adhesives (SABRA). This technique results in higher bond energies due to the creation of free radicals. The surfaces were activated by abrasion with emery paper in the presence of the adhesive itself (epoxy), or of some suitable primer such as methyl methacrylate, acrylonitrile (AN) or hydrogen sulfide gas. The effects of this technique were demonstrated by four different methods: 1) Improved wetting of standard epoxy or water drops on the treated surface. 2) Achievement of bond energies between primers and polymeric surfaces exceeding the energy of solution in solvents, which were revealed by attenuated total reflectance infrared. 3) The detection of free radicals created by bond scission during abrasion by means of diphenylpicryl hydrazyl, (DPPH), a free radical scavenger, monitored by spec-trocolorimetry, 4) Destructive testing of single lap joint test Pieces, scarfed tube joints and pee) test samples. These experiments will be described in a second paper. The theoretical base of the new approach is supported by a tentative estimate of energies set free by mechanochemical creation of free radicals and the excess heat released during abrasion.