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1.
Ceramic coatings were prepared on Ti-6Al-4V alloy in NaAlO2 solution by micro-plasma oxidation (MPO). The salt spray teste of tne coated samples and the substrates were carried out in a salt spray test machine. The phase composition and surface morphology of the coatings were investigated by XRD and SEM. Severe corrosion occurred on the substrate surface, while there were no obvious corrosion phenomena on the coated samples. The coatings were composed of Al2TiO5 and a little α-Al2O3 and rutile TiO2, and the salt spray test did not change the composition of the coatings. The weight loss rate of the coatings decreased with increasing MPO time because of the increase in density and thickness of the coatings. The surface morphology of the coatings was influenced by salt spray corrosion test Among the coated samples, the coating prepared for 2 h has the best corrosion resistance under salt spray test.  相似文献   

2.
The combined microarc oxidation (MAO) and inorganic sealing process was used to deposit a composite coating to improve the corrosion resistance of AZ31 magnesium alloy.The surface morphologies of the resulting duplex coatings were studied by SEM.Furthermore,the corrosion resistance of the coated Mg alloy substrates was investigated using electrochemical workstation and dropping corrosion test.The results show that the composite coating surface consists of Mg,Si,O and Na.It is difficult to deposit inorganic coating on a thick MAO coating surface.As the composite coating was solidified by CO2 under 175 °C,it exhibits a better corrosion resistance than the MAO monolayer,owing to the thick and compact inorganic coating.  相似文献   

3.
The amino-tri-(methylenephosphonic acid) layers were adsorbed on the surface of AA6061 aluminum alloy for improving the lacquer adhesion and corrosion inhibition as a substitute for chromate coatings. The surface structure and characteristic of the amino-tri-(methylenephosphonic acid) layers on AA6061 aluminum alloy were investigated by means of XPS and ATR-FTIR analysis. The analyzed results showed that the amino-tri-(methylenephosphonic acid) adsorption layers adsorb on the surface of aluminium alloy via acid-base interaction in a bi-dentate conformation. After the amino-tri-(methylenephosphonic acid) layers were coated with epoxy resin, the layers showed good adhesive strength and favorable corrosion resistance in contrast to chromate coatings.  相似文献   

4.
The NiCrAIY+ZrO2 thermal barrier coating was prepared on the surface of TiAI alloy by plasma spraying technique. The microstructure and phase structure were analyzed using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The high temperature oxidation resistance of the plasma sprayed samples at 850℃ was investigated. The results show that the bonding between thermal barrier coating and substrate is very good. Surface hardness of TiAI alloy is improved too, The microhardness of the coating surface is about HV 900 after the oxidation test at 850 ℃. The oxidation resistance of the samples is improved remarkably.  相似文献   

5.
In order to solve the high-price and short-lifetime problems of the cutter of agricultural machinery,and improve the wear resistance of the cutter,the TiCN/Fe metal ceramic composite coating was prepared on the substrate of Q235 steel by reaction nitrogen arc cladding technique.The mixture powder of titanium and graphite was preplaced on the Q235 steel surface after inteasive mixing by planetary ball mill and gluing with starch binder.The microstructure and phase of the coatings,interface behavior between coatings and the substrate were investigated by scanning electronic microscope and X-ray diffractometer.The micro-hardness distribution of the coating section was tested by micro-hardness tester.Friction coefficient and wear weight loss were measured by abrasion machine.Wearing surface morphology was investigated by scanning electronic microscope.The results show that an excellent bonding between the coatings and the Q235 steel substrate is ensured by the strong metallurgical interface and phase of the coatings.The coatings are mainly composed of TiCN.The highest microhardness of the coatings reaches 1 089 HV0.2,while the micro-hardness of Q235 steel substrate is only about 286 HV0.2.The anti-abrasive test results show that the wear resistance of the cladding coating is better than that of quenched and tempered 65 Mn steel which is often used as cutter of agricultural machinery.The field test results show that the TiCN/ Fe metal ceramic composite coating prepared by reaction nitrogen arc cladding is feasible to the manufacture and remanufacture of the cutter of agricultural machinery.  相似文献   

6.
TiB2-Ni composite powders were prepared by pressurized hydrogen reduction cladding with different proportion of TiB2.The coatings were then prepared by APS.The microstructures and the phase composition of the powders as well as the deposited coatings were analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The coatings were tested using a ring-on-disc tribometer from ambient temperature to 300°C.A sprayed Cr3C2-NiCr coating was tested as a reference.The morphologies of the worn surface of the coatings were observed and analyzed.It is found that the TiB2-Ni composite coatings present higher friction coefficient than that of the Cr3C2-NiCr coating at room temperature due to the adhesive wear mechanism,whereas the main wear mechanism of Cr3C2-NiCr coating is rupture and exfoliation.However,at high temperature,the friction coefficient of the TiB2-Ni composite coating decreases as a result of B2O3 solid lubricant,which alleviates the adhesive wear on coatings.Furthermore,the TiB2-Ni composite coating greatly reduces the mass loss of the boron cast iron.  相似文献   

7.
Amorphous Ni-S-Co alloy was prepared by means of chemical electro-deposition method on the foam nickel matrix. The surface morphology and microstructure of Ni-S-Co coatings were studied usmg SEM and XRD, and the electrochemical properties were tested by electrochemical methods. The results show that the coating has amorphous structure and the particles of the surface are fine with large specific surface area. The Ni-S-Co alloy is more active with lower potential for hydrogen evolution, higher exchange current density and lower activation energy compared with Ni and Ni-S electrode. Its hydrogen evolution reaction(HER) is enhanced, the size of particles of surface decreases and the surface area increases after being activated by KOH alkaline solution.  相似文献   

8.
Applying a novel method of arc-glow plasma depositing, a 2 lain-thick coating with 12 sub-layers of TiN and CrN was deposited alternately on the surface of magnesium alloy AZglD to improve its wear resistance. The wear behavior was investigated by test of ball on disc sliding. The composition and microstructure of the coating were also analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the morphology of TiN-CrN film was surveyed through scanning electronic microscopy (SEM) and atom force microscopy (AFM).The adhesion strength between film and matrix was evaluated by ways of stick-peeling test. The surface micro-hardness of the coating is above HK0.011 433, and the specific wear ratio of specimens coated with TiN-CrN films tested decreases greatly compared to that of the bare metal.  相似文献   

9.
Pt and Ir coatings were produced by double glow plasma technology on the surface of Ti alloy substrates. The chemical compositions of the coatings were determined by X-ray diffraction and X-ray photoelectron spectroscopy. The microstructure and morphology of the coatings were observed by scanning electron microscopy. The hardness and elastic modulus of the coatings were estimated by nanoindentation. The measurements of adhesive forces of the coatings were performed with scratch tester. The results indicated that the Pt and Ir coatings displayed the preferred (220) orientation due to the initial nuclei with preferred growth on the surface of the substrates. The interface between the Pt coating and substrate exhibited no evidence of delamination. The Ir coating was composed of irregular columnar grains with many nanovoids at the interface between the coating and substrate. The mean values of hardness for Pt and Ir coatings were 0.9 GPa and 9 GPa, respectively. The elastic modulus of Pt and Ir coatings were 178 GPa and 339 GPa, respectively. The adhesive forces of the Pt and Ir coatings were about 66.4 N and 55 N, respectively. The Pt and Ir coatings adhered well to the Ti alloy substrates.  相似文献   

10.
Alumina coating is used to improve the performance of high-temperature oxidation resistance,which can be fabricated on the surface of hydrogen resistance steel by two methods,thermal oxidation of arc ion plated Al coating and reactive magnetron sputtering.Elemental composition,structures and surface morphologies of the coating were analyzed and compared in this paper.The surface of the coatings,which was made by the first method,was composed of α-Al2O3 phase and internal was Fe-Al alloy phase.The Alumina coatings made by the second method were amorphous.In addition,appearances of Alumina coatings fabricated by these two methods were quit different,which were grey and transparent respectively.Both of the two kinds of coatings meet to the needs of high-temperature oxidation resistance.  相似文献   

11.
The electroless Ni-P/Ni-W-P duplex coatings were deposited directly on AZ91D magnesium alloy by an acid-sulfate nickel bath.Nickel sulphate and sodium tungstate were used as metal ion sources and sodium hypophosphite was used as reducing agent.The coating was characterized for its structure,morphologies,microhardness and corrosion properties.The presence of dense and coarse nodules in the duplex coatings was observed by SEM and EDS.Tungsten content in Ni-P/Ni-W-P alloy is about 0.65%(mass fraction) and t...  相似文献   

12.
化学镀Ni-W-P薄膜的制备及其耐蚀性能的研究   总被引:1,自引:1,他引:0  
目的 制备Ni-W-P合金薄膜并研究其耐蚀性.方法 在碱性镀液(pH=11)中,以次亚磷酸钠为还原剂,柠檬酸钠为络合剂,以铜锌合金为基材,采用化学镀制备Ni-W-P薄膜.通过X射线荧光仪、SEM、电化学极化曲线等方法 ,研究还原剂次亚磷酸钠浓度、络合剂柠檬酸钠浓度以及反应时间对薄膜厚度、表面形貌和耐蚀性的影响.结果 固定其他参数不变的条件下,在还原剂浓度为0.2 mol/L及络合剂浓度为0.26 mol/L时薄膜厚度最大,分别为0.2975、0.1978μm.随着次亚磷酸钠浓度的增大,Ni-W-P薄膜表面致密度增加,孔隙率减少.当次亚磷酸钠的浓度为0.1 mol/L时,薄膜表面的颗粒较细小,孔隙较多;当次亚磷酸钠的浓度为0.4 mol/L时,薄膜表面的孔隙明显减少,表面更加均匀且致密度变好;络合剂和还原剂的改变对薄膜腐蚀电位没有明显影响,腐蚀电流密度在还原剂浓度为0.4 mol/L、络合剂浓度为0.28 mol/L时达到最小,分别为2.38×10-6、2.23×10-6 A/cm2;随着络合剂和还原剂浓度的增大,薄膜表面趋于致密;随着反应时间的增加,膜层厚度明显增大,腐蚀电流密度随着时间的增加而减小,化学镀4 h薄膜腐蚀电流密度最小,为1.679×10-6 A/cm2.Ni-W-P薄膜厚度可达到4.14μm.结论 还原剂浓度为0.4 mol/L,络合剂浓度为0.28 mol/L时,薄膜的耐蚀性最好,反应时间的延长有利于薄膜耐蚀性能的优化.  相似文献   

13.
目的研究以三乙醇胺作为络合剂对化学镀Ni-W-P合金镀层的组织结构和腐蚀性能的影响。方法以化学镀的方法在40Cr基体上制备Ni-W-P合金镀层,研究了三乙醇胺对Ni-W-P合金镀层的成分结构、沉积速率、耐蚀性和孔隙率的影响。结果三乙醇胺用量为8 m L/L时镀层W、P质量分数达到峰值,分别为3.63%、9.34%。三乙醇胺用量较低时,镀层具有非晶态结构;三乙醇胺用量达到12 m L/L时镀层开始出现晶态峰,具有混晶态结构。三乙醇胺浓度对镀层的沉积速率和孔隙率具有很大影响,三乙醇胺用量为10 m L/L时,镀速达到最大值14.1μm/h,用量为8 m L/L时,镀层的孔隙率最低,为0.07%。化学镀Ni-W-P合金镀层的耐蚀性随着三乙醇胺浓度的增加,具有先增加后降低的趋势,用量为8 m L/L时,镀层的腐蚀速率最低,为5.6μm/a,耐蚀性最好。结论以三乙醇胺作为络合剂能够得到胞状颗粒且颗粒均匀细小的Ni-W-P合金镀层,对镀层的结构具有一定的影响,可以提高Ni-W-P合金镀层的沉积速率。Ni-W-P合金镀层具有很好的耐蚀性,腐蚀速率最低为5.6μm/a。  相似文献   

14.
7075铝合金化学镀Ni-P/Ni-W-P双层镀层研究   总被引:2,自引:1,他引:1  
以7075铝合金为基体,采用直接连续化学镀法制备Ni-P/Ni-W-P双层膜,并采用SEM,EPMA,XRD和显微硬度计、电化学工作站等对膜层热处理前后的表(断)面形貌、成分、结构、硬度和耐腐蚀等性能进行了研究。结果表明:获得了致密无孔且与基体及层间相互结合紧密的非晶态Ni-P/Ni-W-P膜;热处理后,镀层硬度提高,而耐蚀性略有降低。  相似文献   

15.
目的对NdFeB磁性材料进行表面防护处理,改善其耐腐蚀性能。方法利用化学镀方法,在NdFeB基体材料表面制备氧化物颗粒增强的晶态和非晶态Ni-W-P/Nb2O5复合镀层,对镀层的组织形貌、元素组成分布及物相进行分析,并通过化学腐蚀失重法对耐腐蚀性能进行测试。结果当镀液中的次亚磷酸钠含量为20 g/L时,形成了晶态镀层;为35 g/L时,形成了非晶态镀层。晶态和非晶态Ni-W-P/Nb2O5镀层均由胞状突起组成,其中弥散分布着共沉积的Nb2O5颗粒。镀层样品的XRD图谱中没有出现与钕铁硼相关的衍射峰。对于制备的晶态和非晶态复合镀层,镀液中Nb2O5质量浓度由5 g/L增加到15 g/L时,化学腐蚀速率明显下降;Nb2O5质量浓度由15 g/L增加到20 g/L时,化学腐蚀速率的下降变得缓慢。结论利用化学镀可以在NdFeB磁性材料表面制备致密的Nb2O5增强Ni-W-P复合镀层,且随着Nb2O5含量的增加,复合镀层的耐腐蚀性能提高。  相似文献   

16.
目的研究重防腐涂料环氧玻璃鳞片耐蚀耐磨性能。方法对环氧玻璃鳞片与其它3种环氧类涂层进行磨耗实验,通过紫外线老化、低温暴露和盐雾等系列力学和耐腐蚀性能检测,研究环氧玻璃鳞片的耐腐蚀性能。结果各涂层都符合磨损性能指标(1000转的磨耗量小于1.8 g),环氧玻璃鳞片的耐磨性比环氧树脂涂层较差,但是比另外两种环氧类涂层耐磨性都好;耐蚀循环2400 h后,4种不同环氧类涂层表面均出现粉化、锈点,变色明显;环氧玻璃鳞片的结合力好于其他3种达到6.7 MPa,并且划线处的起泡数目最少,单边扩蚀只有2.5 mm,失光率最小。结论环氧玻璃鳞片涂层中由于鳞片的层状分布,延缓了腐蚀介质的渗透,具有良好的耐磨耐蚀性能,可以作为一种高效的重防腐涂料,应用于海洋、船舶等环境中。  相似文献   

17.
AZ91D镁合金化学镀Ni-P及Ni-W-P镀层的结构与耐蚀性   总被引:1,自引:0,他引:1  
在AZ91D镁合金上直接化学镀Ni-P和Ni-W-P镀层,并利用扫描电子显微镜、X射线衍射仪及电化学工作站研究后续热处理对化学镀层组织形貌、相组成及其耐蚀性的影响。结果表明,制备的Ni-P镀层为非晶态,而Ni-W-P镀层为纳米晶结构,两者在3.5%NaCl水溶液中的耐蚀性相当。热处理可以明显提高Ni-W-P镀层的耐蚀能力,但却稍微弱化Ni-P镀层的耐蚀能力,热处理后的Ni-W-P层自腐蚀电位相对于未处理的化学镀Ni-W-P或Ni-P层提高了约150 mV。  相似文献   

18.
目的提高静电喷涂疏水涂层的附着力。方法采用硅烷偶联剂和聚二甲基硅氧烷制备了表面改性疏水二氧化硅粉末。将一定比例的聚偏氟乙烯粉末、超高分子量聚乙烯粉末与疏水二氧化硅粉末混合,制备了复合型疏水粉末。使用环氧树脂、固化剂、活性剂等配制了导电环氧树脂。通过静电喷涂工艺将复合疏水粉末喷涂到已用导电环氧树脂覆盖的铝基板表面,经过中温固化,制得了铝合金疏水复合涂层。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、接触角测量仪(CA)、百格刀附着力测试仪等,对疏水复合涂层进行测试表征。结果 SEM结果表明涂层表面构建了微米-纳米的阶层粗糙结构,经CA测试,该表面具有较好的疏水性。当混合粉末中聚二甲基硅氧烷改性二氧化硅的比例占到20%时,环氧基疏水涂层的接触角最高可达到140°,滚动角最低可达5°,附着力的等级为0级,同时疏水涂层的耐磨性和耐腐蚀性良好。结论采用简单、易于工业化的静电喷涂工艺制备了高附着力的疏水涂层,具有广泛的应用前景。  相似文献   

19.
以不锈钢为基体材料,Ni-W-P为基质合金,添加耐磨微粒碳化硅(SiC)和六方氮化硼(-αBN)固体润滑微粒,在抛光轮工作面镀制Ni-W-P/SiC BN多元复合镀层。该工艺得到的Ni-W-P/SiC BN多元复合镀层表面光亮、质感均匀、镀层结合力良好、耐蚀性优良。经过相同次数磨损试验,Ni-W-P/SiC BN热处理镀层的耐磨性能是0Cr18Ni9Ti不锈钢的5.22倍。  相似文献   

20.
退火对化学镀Ni-W-P合金晶化及耐蚀性的影响   总被引:1,自引:0,他引:1  
在不同温度下对制备的Ni-W-P合金镀层进行退火处理,利用X射线衍射技术定量分析了镀层的晶化、晶粒尺寸和晶格应变,采用扫描电镜(SEM)和光学显微镜观察了镀层腐蚀前后的表面形貌,并通过在0.5mol/L H2SO4溶液中的浸泡腐蚀速率和阳极极化曲线对退火前后镀层的耐蚀性进行了分析.结果表明:Ni-W-P镀层在镀态为非晶...  相似文献   

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