阳极氧化钽酸锂薄膜在NaOH溶液中的腐蚀行为研究

通过阳极氧化法在高纯钽片表面制备了钽酸锂复合薄膜,采用浸泡失重法和电化学测试法考察了镀膜前后样品在10% (质量分数) NaOH溶液中的腐蚀行为。利用X射线衍射仪、扫描电子显微镜及能谱仪分别对薄膜的物相组成、表面及截面形貌、膜层厚度进行了测试分析。结果表明,阳极氧化后得到的复合薄膜由钽酸锂和氧化钽组成;该薄膜与基体之间结合良好,厚度约3 μm;镀膜后样品的质量腐蚀速率至少减少了6倍,腐蚀电流密度下降了2个数量级,腐蚀96 h后样品表面没有明显变化。而对比的纯钽样品却发生了严重的腐蚀反应,生成了很多长条状和多棱柱状的腐蚀产物Na₃TaO₄、Na₂Ta₂O₆和Na₈Ta₆O₁₉。     

甘油磷酸钙浓度对钛合金MAO涂层性能的影响

目的 提高医用钛合金的生物活性。方法 在含葡萄糖酸钙(Ca Glu₂)、葡萄糖酸镁(MgGlu₂)、植酸钠(Na₁₂Phy)和磷酸(H₃PO₄)的基本溶液中,分别添加8、10、12 g/L甘油磷酸钙(Ca-GP),采用MAO方法在Ti-6Al-4V表面制备3种涂层。使用SEM、EDS、XRD、XPS和AFM检测涂层表面形貌、化学成分、物相结构、元素存在状态和表面粗糙度,并测试涂层的接触角、结合强度以及体外生物活性。结果 经过MAO处理后,钛合金表面可成功生长出多孔陶瓷涂层,Ca-GP参与了MAO涂层形成。当Ca-GP的质量浓度为8 g/L时,涂层非常粗糙,Ca和Mg的原子数分数分别为7.56%和1.74%。随着Ca-GP浓度的增加,微孔均匀性变好,表面微裂纹减少,且钙磷原子比(Ca/P)显著提高。在含8、10 g/L的Ca-GP溶液中,制备的涂层以Ti、锐钛矿和金红石型Ti O2组成为主;在12g/L的Ca-GP溶液中生成的涂层,Ca/P原子比可达1.77,含有Ti P     

Al2O3包覆改善P2型Na2/3Fe1/2Mn1/2O2正极材料的存储性能

采用超声喷雾热解与高温固相烧结相结合的方法合成P2型Na_2/3Fe_1/2Mn_1/2O₂材料。通过X射线衍射仪、扫描电子显微镜和电化学充放电设备对材料的结构、形貌和电化学性能进行全面的表征。此外,在Na_2/3Fe_1/2Mn_1/2O₂表面包覆Al₂O₃薄层,该包覆层可以抑制Na₂CO₃·H₂O的形成,提高Na_2/3Fe_1/2Mn_1/2O₂材料的存储性能,从而改善其电化学性能。这种简单的表面改性方法为合成高性能钠离子电池正极材料提供了新思路。     

K452合金表面CVD渗铝涂层制备温度对其750℃硫酸盐热腐蚀行为的影响

采用化学气相沉积(CVD)技术在K452合金表面沉积渗铝涂层,沉积温度分别为850、950和1050℃。研究了沉积温度对CVD渗铝涂层在750℃空气中表面沉积Na₂SO₄及Na₂SO₄+NaCl环境下热腐蚀行为的影响。采用扫描电子显微镜(SEM)、X射线能谱仪(EDS)和X射线衍射仪(XRD)对腐蚀前和后的试样进行截面形貌观察和物相结构分析。结果表明,在750℃下表面沉积Na₂SO₄及Na₂SO₄+NaCl热腐蚀50 h后,3种涂层试样均表现出了较K452合金更好的抗热腐蚀性能,且涂层的抗热腐蚀性能随着涂层沉积温度的增加而增强。     

Si–Yb2O3/Yb2Si2O7/Yb2SiO5 EBC涂层组织结构及熔盐腐蚀行为研究

目的 研究Si–Yb₂O₃/Yb₂Si₂O₇/Yb₂Si O₅ 3层EBC涂层的抗熔盐腐蚀性能。方法 采用真空等离子喷涂工艺在试样表面单面制备Si–Yb₂O₃/Yb₂Si₂O₇/Yb₂Si O₅ 3层结构的EBC涂层,选用尺寸为Ф25 mm、厚度为5 mm的SiC_f/SiC复合材料基体试样,在900℃、NaCl(质量分数为50%)+Na₂SO₄(质量分数为50%)混合盐中进行连续100 h的熔盐腐蚀试验,采用光学显微镜、扫描电镜、X射线衍射仪等观察和测试3层EBC涂层熔盐腐蚀前后的形貌,分析其组织结构以及该EBC涂层在熔盐腐蚀过程中的化学反应机理。结果 经过连续100 h、900℃的熔盐腐蚀,基体SiC_f     

钛合金表面激光重熔微弧氧化层的组织结构及摩擦磨损性能

为改善TC21钛合金表面微弧氧化(micro arc oxidation,MAO)涂层的微观结构致密性和耐磨性能，对MAO涂层进行了激光重熔改性，并对重熔后涂层的微观结构、成分、相组成以及硬度、摩擦磨损性能等进行了表征测试。结果显示，重熔MAO涂层由重熔外层、重熔内层和热影响层3层结构组成，其中外层和内层主要由Al₂TiO₅、rutile-TiO₂和α-Al₂O₃组成，热影响层由α-Ti和β-Ti转变组织组成，重熔MAO涂层的硬度显著增大。在摩擦磨损实验中，重熔MAO涂层摩擦系数低于MAO涂层和TC21钛合金基体，其磨损机制以粘着磨损为主，并伴有轻微的磨粒磨损。激光重熔MAO涂层显著提高了TC21钛合金摩擦磨损性能。     

喷涂工艺对Ta2O5原位复合钽基纳米晶涂层微观结构及摩擦磨损性能的影响

采用大气等离子喷涂制备了Ta₂O₅原位复合钽基纳米晶涂层,利用SEM、微束XRD、微动摩擦磨损实验机及非接触三维表面轮廓仪等技术手段并结合计算分析,考察了喷涂功率、主气(Ar)流量等对钽基涂层表面Ta₂O₅含量、晶粒尺寸、显微硬度和摩擦磨损性能等的影响规律及原因。在考察范围内,随喷涂功率增大,钽基涂层表面Ta₂O₅含量呈先减小后增大的变化,而涂层表面α-Ta的晶粒尺寸及点阵畸变则均呈先增大后减小的变化;随Ar气流量增大,涂层表面Ta₂O₅含量总体呈减小趋势,在流量为2.17×10^-3~2.33×10^-3m³/s时达到最低,α-Ta的晶粒尺寸与点阵畸变的变化呈负相关性;采用间断喷涂方法时涂层表面Ta₂O₅含量降低,α-Ta晶粒尺寸及点阵畸变均略有减小。通过对喷涂相关微观过程特点的分析,对这些规律作了阐释。涂层的显微硬度与其表面Ta₂O₅含量相关,高硬度涂层的表面Ta₂O₅含量相对较低;干摩擦条件下晶粒较大、Ta₂O₅含量较少的涂层抵御硬质陶瓷低速刻划的能力较差;边界润滑状态下硬度较高的涂层表现出更优的抗磨减摩性能;采取间断喷涂可获得摩擦学性能最佳的涂层。钽基涂层的机械性能与其微观结构特征显著相关;除显微硬度外,涂层晶粒尺寸、点阵畸变及表面Ta₂O₅含量的相对值可用作质量控制的重要指标。     

(NiCoCrAlYSiB+AlSiY)复合涂层热腐蚀行为的研究

采用电弧离子镀（AIP）技术在镍基单晶高温合金基体上制备了NiCoCrAlYSiB涂层（普通涂层）和（Ni-COCrAlYSiB+AlSiY）复合涂层,研究了高温合金基体与2种涂层分别在900和700℃下的涂盐（Na₂SO₄+K₂SO₄和Na₂SO₄+NaCl）热腐蚀行为.结果表明:高温（900℃）热腐蚀条件下,基体合金表面主要生成NiO;普通涂层表面上要生成Cr₂O₃,而且涂层内部出现内氧化和内硫化现象;复合涂层表面主要生成Al₂O₃,外层出现程度较轻的内氧化,涂层表层Al含量仍然较高,维持表面Al₂O₃膜的形成和修复.低温（700℃）热腐蚀条件下,基体合金表面主要生成NiO;普通涂层表面主要生成Cr₂O₃,涂层内部出现严重的内氧化;复合涂层表面也出现了内氧化,高Cr的内层未受腐蚀,有助于提高涂层的抗腐蚀性能.     

(NiCoCrAlYSiB+AlSiY)复合涂层热腐蚀行为的研究

采用电弧离子镀（AIP）技术在镍基单晶高温合金基体上制备了NiCoCrAlYSiB涂层（普通涂层）和（Ni-CoCrAlYSiB+AlSiY）复合涂层,研究了高温合金基体与2种涂层分别在900和700℃下的涂盐（Na₂SO₄+K₂SO₄和Na₂SO₄+NaCl）热腐蚀行为.结果表明:高温（900℃）热腐蚀条件下,基体合金表面主要生成NiO;普通涂层表面主要生成Cr₂O₃,而且涂层内部出现内氧化和内硫化现象;复合涂层表面主要生成Al₂O₃,外层出现程度较轻的内氧化,涂层表层Al含量仍然较高,维持表面Al₂O₃膜的形成和修复.低温（700℃）热腐蚀条件下,基体合金表面主要生成NiO;普通涂层表面主要生成Cr₂O₃,涂层内部出现严重的内氧化;复合涂层表面也出现了内氧化,高Cr的内层未受腐蚀,有助于提高涂层的抗腐蚀性能.     

纳米颗粒对ZM5镁合金微弧氧化涂层耐磨和耐蚀性能的影响

目的 进一步提高ZM5镁合金微弧氧化(MAO)涂层的耐磨和耐蚀性能。方法 在镁合金表面制备了不含与含有SiC和CeO₂纳米颗粒的3种MAO涂层。使用扫描电子显微镜(SEM)、能量色散X射线光谱仪(EDS)和X射线衍射仪(XRD),对MAO涂层的表面形貌和成分结构进行分析,通过摩擦试验测试了涂层的耐磨性能,通过极化曲线(Tafel)和电化学阻抗谱(EIS)测试了涂层的耐蚀性能。结果 含有SiC纳米颗粒的MAO涂层厚度、硬度分别提升了19.40%、86.56%,含有CeO₂纳米颗粒的MAO涂层厚度、硬度分别提升了3.74%、44.59%。含有SiC纳米颗粒的涂层孔隙率升高6.60%,而添加Ce O2使涂层的孔隙率下降23.90%。摩擦试验表明,不含纳米颗粒的MAO涂层磨痕深度为36.4μm,而含有纳米颗粒的涂层磨痕深度可以忽略不计。Tafel试验表明,CeO₂纳米颗粒可以显著降低MAO涂层的腐蚀电流密度,从1.41×10^-9 A/cm²降至5.72×10^-10...     

固体润滑剂WS2对铝合金微弧氧化陶瓷膜摩擦学性能的影响

目的 改善微弧氧化陶瓷膜层的摩擦学性能。方法 采用微弧氧化技术和抛磨技术相结合的方法在ZL109合金表面制备微弧氧化陶瓷和固体润滑剂复合膜层。利用粗糙度仪检测试样表面粗糙度,并在球盘往复式摩擦磨损试验机下检测复合膜层的摩擦学性能。使用扫描电镜（SEM）分析试验前后试样表面微观形貌及对磨钢球磨斑形貌,并利用能谱分析仪（EDS）对试样膜层化学成分进行分析。结果 在抛磨纳米WS2粉体过程中,WS2可有效填充陶瓷膜疏松层上的放电微孔以及经抛光的陶瓷膜层表面残留的微孔缺陷,并极大地降低试样表面粗糙度,进而影响实验前期的摩擦系数及抗粘着时间。试样MAO-W比试样MAO粗糙度降低约34.2%,摩擦系数降低79.2%,抗粘着时间增加900%。试样P-MAO-W比试样P-MAO粗糙度降低约41.3%,摩擦系数降低93.6%,抗粘着时间增加233%。另外,制备的试样可以有效减轻对磨钢球的磨损,并且试样的磨痕宽度及对磨钢球的磨斑直径变化规律与摩擦过程中的摩擦系数变化及粗糙度变化趋势相吻合。结论 在铝合金微弧氧化陶瓷膜层表面抛磨纳米WS2自润滑粉体可有效降低摩擦,延长抗粘着时间并减轻对磨件的磨损。     

生物活性多孔钽支架的构建及其初步生物学评价

表面生物活性涂层构建是提升金属内植物骨整合能力的有效途径,本研究利用电化学沉积技术在多孔钽支架表面构建生物活性羟基磷灰石(HA)涂层。通过接触角和比表面积测试发现,HA涂层的构建显著提升了多孔钽表面亲水性,并增加了其比表面积。利用模拟体液浸泡试验评估支架生物活性,发现仅浸泡3天后,多孔钽支架表面就已被类骨磷灰石沉积所覆盖。建成骨细胞培养模型,通过激光共聚焦观察及细胞增殖测试发现,所有支架均具有良好的细胞相容性。并且,细胞共培养5天后,HA涂层化多孔钽支架表面细胞的增殖率分别是未改性材料组和空白对照组的1.1和1.4倍,呈现了更大的促细胞增殖潜力。本研究中所制备的生物活性多孔钽支架具备快速诱导类骨磷灰石沉积能力,能够促进成骨细胞在其表面的贴附和增殖,在骨修复领域具有较大的临床应用前景。     

不同腐蚀环境中几种典型涂层在玻璃钢表面的附着力研究

利用加速腐蚀实验、附着力测试、红外光谱分析等手段,研究了几种典型涂层与环氧玻璃钢底材的附着力及其影响因素。玻璃钢与环氧涂层的附着力与玻璃钢表面的粗糙度和润湿性能有关,当玻璃纤维布外露时,涂层附着力最高;240#砂纸打磨底材后涂层附着力高于60#及600#砂纸打磨底材的涂层附着力。不同涂层在玻璃钢表面的附着力与涂层中主要官能团的极性有关,含有极性较强的多卤素键的氟碳树脂漆表现出较强的附着力;与环氧涂层相比,聚氨酯涂层和聚硅氧烷涂层除含有与环氧涂层相同的酯键、醚键外,还因含有氨酯键、硅氧键等极性键,显示出较高的附着力。对比40 ℃浸泡实验、盐雾实验和湿热实验的结果,40 ℃浸泡实验对涂层附着力降低的影响更大;红外光谱分析表明,40 ℃浸泡与盐雾实验相比涂层内部的分子降解程度更明显。     

Characteristics and biological responses of novel coatings containing strontium by micro-arc oxidation

The modification of micro-arc oxidation (MAO) technique is an effective method to improve biocompatibility of titanium. This study aimed to investigate the coatings formed in the electrolytes with different strontium content, which is beneficial for biological performance. The physicochemical characteristics and cell behavior were assessed. The physicochemical characteristics were investigated using scanning electron microscope (SEM) observation, energy dispersive X-ray spectrometer (EDX), thin film X-ray diffraction (TF-XRD) analysis, electron spectroscopy for chemical analysis (ESCA) and surface roughness test. Cell behavior included morphology observation by SEM and number count by methylthiazoletetrazolium assay of hFOB cells. The TF-XRD results indicated that phase of coatings was anatase and rutile. The calcium, phosphorus, and strontium were detected in the coatings by EDX and ESCA. Using the SEM, the surface morphology exhibited uniform porous structure on titanium. Cell culture experiments demonstrate that MAO coating formed in the electrolytes with different strontium content would not alter initial cell morphology and 1-day and 7-day cell numbers. The cell proliferation of coatings containing 1% or 5% strontium content at 14-day culture was higher than coatings without strontium content at 14-day culture, but the higher strontium content (10%) could not be beneficial to cell growth. Consequently, this study indicates that strontium incorporated into MAO coatings did not change the physicochemical characteristics but exhibited an effect on biological responses.     

钽涂层多孔钛合金支架的制备与表征

钽金属是一种理想的医用金属材料,能够与人体软/硬组织发生整合。利用化学气相沉积方法,在可控多孔结构的Ti6Al4V合金支架表面沉积涂覆钽金属涂层,使其同时具备理想的三维孔隙结构和力学相容性,以及钽金属优异的生物学性能。研究结果显示,多孔钛合金支架表面涂层前后色泽发生明显变化,涂层后支架呈现钽金属色泽。扫描电镜和XRD分析进一步证明了多孔钛合金支架表面沉积物为钽金属。与美国Zimmer公司生产的多孔钽小梁金属相比,钽涂层多孔钛合金支架具备与人体皮质骨更相似的弹性模量和抗压强度,是一种理想的骨修复替代物。     

Influence of microarc oxidation and hard anodizing on plain fatigue and fretting fatigue behaviour of Al-Mg-Si alloy

The present study compares the performance of microarc oxidation (MAO) and hard anodizing (HA) treated Al-Mg-Si alloy (AA6063) test samples under cyclic loading in uniaxial tension with a stress ratio of 0.1 (plain fatigue) and fretting fatigue loading. Fatigue test specimens were treated using MAO and HA techniques. MAO coated specimens were ground to reduce the surface roughness comparable with that in HA coated specimens. In that process the porous outer layer was removed. Characterization of coated and uncoated specimens was done with reference to the coating morphology, microhardness, surface roughness and residual stress. The specimens were tested under plain fatigue and fretting fatigue loading at ambient temperature. While the ground MAO coating exhibited relatively less amount of porosity, HA coating had through thickness cracks. MAO coating had compressive residual stress and it was very hard compared with HA coating. Both types of coated samples exhibited slightly higher friction force than that experienced by the uncoated specimens. Fretted region of the HA coated samples was rougher than that of the MAO coated specimens. Plain fatigue lives of both coated samples were inferior to those of the uncoated specimens. The inferior plain fatigue lives of MAO coated specimens compared with those of the substrate may be attributed to the tensile residual stresses supposedly present in the substrate leading to an early crack initiation in the substrate adjacent to the coating. As friction force of MAO coated samples was higher than that experienced by uncoated specimens, the fretting fatigue lives of MAO coated samples were slightly inferior to those of uncoated samples. As the anodized layer had preexisting through thickness cracks and strong adhesion with the substrate, cracks propagated from HA coating through the interface into the substrate easily. This may be the reason for the HA coated samples exhibiting inferior plain fatigue and fretting fatigue lives compared with MAO coated and uncoated samples.     

SiC纳米颗粒对TA2微弧氧化涂层组织结构及耐蚀性能的影响机制

为提高钛及钛合金防腐蚀、耐磨损等关键服役性能,本研究在TA2钛合金表面制备微弧氧化陶瓷涂层,研究纳米SiC颗粒的添加对微弧氧化涂层组织结构及耐蚀性能的影响机制.结果表明,基础电解液中SiC的加入能够大幅度提高TA2微弧氧化涂层的厚度,且随着电压的升高,涂层的厚度和表面粗糙度也随之增大,涂层表面的微孔尺寸随着电压的升高而逐渐增大,SiC的加入能够有效地抑制微弧氧化涂层表面裂纹的产生;微弧氧化涂层的物相主要有高温稳定相金红石及锐钛矿,还含有少量的SiC及SiO2;微弧氧化涂层增加TA2的开路电位及自腐蚀电位,随着处理电压的增加开路电位随着升高;SiC的加入降低了涂层的阳极电流密度,显著提高了微弧氧化涂层得耐蚀性能。     

氟钛酸钾添加对铝镁复合板微弧氧化涂层结构及耐蚀性的影响

为研究氟钛酸钾(K₂TiF₆)添加对Al-Mg复合板微弧氧化涂层结构和耐腐蚀性能的影响,在硅酸盐-氢氧化钠电解液体系中加入不同浓度的氟钛酸钾(0、1、2和3 g·L^-1),利用微弧氧化技术(MAO)在Al-Mg复合板表面制备陶瓷氧化物涂层。通过SEM、XRD、EDS和电化学工作站等对制备陶瓷氧化物涂层显微组织、相组成、形貌及耐蚀性能进行表征。添加K₂TiF₆后,Al-Mg复合板Al侧的涂层厚度、表面孔隙率和表面粗糙度随K₂TiF₆浓度的增加呈下降的趋势(24.2～18.4μm、6.8%～5.3%、3.55～2.23),Mg侧涂层呈上升趋势(21.0～26.6μm、3.6%～5.3%,3.35～4.33),此外涂层中的Ti和F元素含量增加,各样品的耐蚀性均有所提高。添加K₂TiF₆为2 g·L^-1时,两侧涂层的耐蚀性最好,其中R_t均比未添加的样品增加...     

Untersuchungen zur Ta-Beschichtung von Stahl durch Vakuumplasmaspritzen

Investigations of tantalum coatings on steel by vacuum plasma spraying In this work the possibilities of the production of tantalum coatings by vacuum plasma spraying were investigated. Suitable parameters of the vacuum plasma spraying process were determined, and the quality of vacuum plasma sprayed tantalum coatings was evaluated with regard to chemical composition, adhesion strength, density and corrosion behaviour. To obtain high-quality coatings it was necessary to apply sufficient plasma power as well as an optimal injection of spraying powder into the plasma torch. A complete melting of the tantalum powder particles could not he achieved. The coatings obtained showed a good adhesion strength but a low formability (ductility). The corrosion resistance against HCL and HNO₃ was evaluated by curves of the current density versus potential. With the aid of the passive current density it was determined that the corrosion resistance of the sprayed coatings was not as excellent as of compact tantalum. The increased surface roughness was not significant with respect to the corrosion behaviour. The reduced corrosion resistance could be caused probably by a high oxygen content of the tantalum powder, especially by oxides around individual powder particles. In contrast to tantalum, vacuum plasma sprayed titanium coatings showed the same corrosion resistance as compact titanium under the same testing conditions.