等离子喷涂SrAl_2O_4涂层的发光性能

把发光材料稀土铕、镝掺入铝酸锶为喷涂材料,用等离子喷涂法, 将材料喷涂在钢板上.利用X射线衍射、扫描电子显微镜等分析手段对铝酸锶涂层的微观结构进行研究.通过发光光谱对铕、镝掺杂的铝酸锶涂层的发光性能进行表征,并对涂层的发光机制做初步探讨.     

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。     

等离子喷涂生物活性涂层的梯度结构表征

采用自动控制的等离子喷涂系统,在钛合金基体上制备出生物活性梯度涂层,利用纳米硬度计、扫描电镜等对生物活性涂层的梯度结构进行分析.实验结果表明:金属基体与陶瓷界面区域的弹性模量和硬度呈梯度变化;生物活性功能涂层表面分布着不同尺寸范围的孔洞,具有典型的多孔结构特征,整个涂层沿垂直基体方向从底层致密结构向表面层多孔结构过渡;涂层成分底层生物稳定性至表面层生物活性呈梯度变化,涂层表面成分为生物活性的羟基磷灰石.涂层的这种结构特征有利于改善生物活性涂层的综合性能,提高涂层与基体的结合强度,根据ASTM C633-79测试生物活性涂层与基体的结合强度,结合强度达到48.6 MPa.     

等离子喷涂涂层材料

本文介绍中国科学院上海硅酸盐研究所在研制，开发、应用等离子喷涂涂层材料方面所取得的一些进展，主要有(1)涂层的物理，力学，热学性能和微观结构；(2)涂层性能与其微观结构间关系；(3)涂层的摩擦．磨损行为和机理，(4)涂层的生物相容性，(5)涂层在工业上的应用。     

等离子喷涂陶瓷涂层的研究

等离子喷涂陶瓷涂层具有高硬度、高熔点、耐磨、耐腐蚀、隔热、绝缘等特点，巳成为近年来热喷涂行业研究发展的重要方向，并日益广泛地应用于零部件的表面防护与强化。     

等离子喷涂制备典型涂层研究进展

从航空航天到交通运输、电子设备和医疗器械等,大大小小的行业中均可见到涂层的应用,涉及到这些领域的涂层种类主要有耐磨、耐蚀涂层、热障涂层、压电陶瓷涂层和生物陶瓷涂层等。等离子喷涂技术具有喷涂材料范围广、工艺简单等优点,是制备上述典型涂层的常用工艺方法。虽然同种工艺可制备出不同种类涂层,但由于所选的喷涂材料、喷涂参数不同,所获得的涂层性能和涂层结构之间也存在着一定差异,须对等离子喷涂各类涂层的研究进行分析与总结。基于此,文中简要介绍了国内外等离子喷涂涂层的应用现状,之后从不同种类涂层功能需求和技术特点出发,分析喷涂工艺对涂层结构和性能的影响。最后对提升涂层性能的工艺方法进行总结,并对今后等离子喷涂涂层技术的发展趋势进行了展望。     

大气等离子喷涂及固相反应法制备MnCoCu金属连接体防护涂层

目的 锰钴尖晶石涂层可有效抑制金属连接体高温氧化、降低固体氧化物燃料电池(SOFC)性能衰减,但其成本较高,电性能和稳定性也需进一步提升。方法 本文拟采用大气等离子喷涂技术(APS)和固相反应法以金属粉末制备高电导率尖晶石涂层。通过Cu元素的添加,在尖晶石涂层中引入高电导率的铜锰尖晶石相,获得高电导率尖晶石涂层,并通过对涂层的相组成、表面截面形貌、元素分布、电性能等物性的表征,揭示Cu添加量及固相转变条件对尖晶石涂层性能的影响规律。结果 800℃热处理后涂层明显致密化、均匀化,涂层主相为Cu_xMn_3-xO₄(x=1, 1.2, 1.4)和MnCo₂O₄;在基体和涂层的界面处存在Cr富集,800℃氧化10h后,含Cu量12%(质量分数)的试样面比电导最高;氧化100h后,面比电导有所下降,含Cu量12%(质量分数)试样仍具有最高的面比电导;经过还原的试样面比电导明显低于未还原样品,其原因在于还原过程中Cr元素产生扩散,氧化后生成了较多的低电导率相。涂层导电性随Cu含量的增加而增大...     

碳钢表面等离子喷涂Cr_2O_3涂层及其耐腐蚀性能

利用等离子喷涂技术在45~#钢表面喷涂Cr_2O_3涂层。用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)等方法表征了涂层的微观形貌、表面元素组成以及相结构;测量了涂层的显微硬度;采用CS300P型电化学工作站检测了Cr_2O_3涂层的耐蚀性能。结果表明,在45~#钢表面等离子喷涂Cr_2O_3涂层的厚度约为100μm,相成分主要是Cr_2O_3;显微硬度值达到莫氏9级;喷涂Cr_2O_3涂层后的试样腐蚀速率显著降低,耐蚀性能明显提高。     

等离子喷涂Al_2O_3-TiO_2防滑涂层制备及其耐磨性

采用等离子喷涂技术制备了两种颗粒度的Al2O3-13%TiO2防滑涂层。采用扫描电镜(SEM)、X射线衍射仪(XRD)等对涂层的组织结构进行了表征,利用FW14往复摩擦试验机测定涂层的防滑性能,通过MMS-1G高速摩擦试验机评价了涂层摩擦学行为。结果表明,涂层致密度较高,两种涂层晶相都以γ-Al2O3为主并含有一定量非晶相;涂层防滑性能良好;两种涂层耐磨性能良好,低速时涂层失效形式以颗粒"拔出"为主,随着速度增加,层间裂纹扩展引起的层片剥落主导了涂层的磨损失效。     

火焰喷涂和等离子喷涂FeCrBSi涂层及其防滑和耐磨性能研究

目的采用大气等离子喷涂(APS)和火焰喷涂(FS)在304不锈钢基体上制备FeCrBSi涂层,并对比研究两种工艺制备涂层的防滑和耐磨性能。方法通过光学显微镜、场发射扫描电镜和X射线衍射仪对涂层的显微形貌和结构进行分析,通过维氏硬度计测试涂层的显微硬度。采用摩擦磨损试验机和三维光学显微镜,测量涂层在干摩擦条件下的摩擦系数和磨损量。结果两种喷涂方法制备的涂层多孔,在喷涂过程中极少发生氧化。与火焰喷涂涂层(749HV0.1)相比,大气等离子喷涂涂层(837HV0.1)具有更高的维氏硬度值。在摩擦试验中,火焰喷涂涂层的磨损率为(38.63±2.37)×10~(-6)m~3/(N·m),而大气等离子喷涂涂层的磨损率为(9.5±0.49)×10~(-6)m~3/(N·m),但两种涂层的摩擦系数区别较小,在频率2 Hz、载荷10 N的条件下的摩擦系数为0.6~0.7。结论两种涂层的磨损机制均为疲劳磨损,喷涂态FeCrBSi涂层具有较好的防滑耐磨性能,且大气等离子喷涂涂层性能优于火焰喷涂涂层。     

Al_2O_3含量对等离子喷涂TiO_2-Al_2O_3陶瓷涂层组织性能的影响

采用大气等离子喷涂方法制备TiO2–Al2O3陶瓷涂层,利用SEM和XRD分析了涂层的显微组织和相结构,并研究了涂层的电阻率随温度变化的规律。研究结果表明:TiO2–Al2O3陶瓷涂层主要由金红石型TiO2、锐钛矿型TiO2、Magneli相、α–Al2O3及γ–Al2O3组成。涂层的显微硬度和电阻率随Al2O3含量的增加而增加,在通电升温条件下涂层的电阻率随温度升高而降低。     

等离子喷涂PZT涂层的制备与性能分析

用等离子喷涂方法在45号钢基体表面制备了锆钛酸铅(PZT)陶瓷涂层,并用扫描电镜(SEM)、X射线衍射仪(XRD)、透射电镜（TEM）、纳米压痕测量仪和d33准静态测量仪等检测手段对涂层的微观形貌、成分、纳米硬度、弹性模量和压电常数等各项性能进行分析,并测量涂层的介电温谱。结果表明：等离子喷涂制备的PZT陶瓷涂层具有典型的层状结构,结构致密,孔隙率为1.96%;纳米硬度和弹性模量平均值分别为5.881 GPa和113.413 GPa;压电常数达到了74 pC/N,并且由介电常数与温度关系图可推知PZT的居里温度约为370 ℃。制备的PZT涂层性能良好,使其在实际工况中的使用成为可能。     

Nd:YAG laser irradiation effects on electrical properties of polycrystalline Li0.5Fe2.5O4

The polycrystalline spinel structured Li_0.5Fe_2.5O₄ ferrite have been prepared by conventional double sintering ceramic method. The samples were palletized and irradiated by Nd:YAG laser with different laser fluencies and characterized by infrared spectroscopy and DC electrical resistivity in order to obtain phase, crystal structure and conduction mechanism in pristine and irradiated samples. The infrared spectroscopy is employed to study the local symmetry and conduction mechanism in crystalline solids before and after irradiation. The DC electrical resistivity measured by two-probe technique from room temperature to beyond Curie temperature with steps of 10 K increases after laser irradiation. Variation of dielectric properties like dielectric constant and dielectric loss tangent is also measured as a function of temperature. A significant reduction in the values of dielectric constant and dielectric loss tangent has been observed with the increase of laser dose.     

Synthesis of Cr-Al2O3 Cermet Selective Surfaces Coated by SnO2 Thin Film by Air Plasma Spraying

High efficient Cr-Al2O3 cermet selective surfaces coated by sol-gel SnO2 thin film for high-temperature application were synthesized by air plasma spraying(APS),followed further heat and polish treatment.The phase composition and micro morphology of coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM)and roughmeter respectively.The solar absorptance(α)and thermal emittance(ε)were determined by optical spectrum instrument.The results show that Cr-Al2O3 cermet coating has a high absorptivity nearly 0.90.But unfortunately,the emissivity of these coatings is nearly 0.50 because of the big thickness and coarse surface prepared by APS technique.However,once coated SnO2 thin film,the composite coatings exhibit excellent selective absorbing property of α=0.89 and ε=0.12.Thus,SnO2 thin film plays a significant role in decreasing the emissivity of coatings as antireflection layer.And furthermore,the optical performance shows that more metal content and smooth surface are favorable for the selective absorbing property.Moreover,the coatings have excellent bond strength with stainless steel substrate and thermal shock resistance at high temperature.     

Preparation of Ni0.5Zn0.5Fe2O4/SiO2 nanocomposites and their adsorption of bovine serum albumin

The magnetic nanocomposites of (1 − x)Ni_0.5Zn_0.5Fe₂O₄/xSiO₂ (x = 0-0.2) were synthesized by the citrate-gel process and their absorption behavior of bovine serum albumin (BSA) was investigated by UV spectroscopy at room temperature. The gel precursor and resultant nanocomposites were characterized by FTIR, XRD, TEM and BET techniques. The results show that the single ferrite phase of Ni_0.5Zn_0.5Fe₂O₄ is formed at 400 °C, with high saturation magnetization and small coercivity. A porous, amorphous silica layer is located at the ferrite nanograin boundaries, with the silica content increasing from 0 to 0.20, the average grain size of Ni_0.5Zn_0.5Fe₂O₄ calcined at 400 °C reduced from about 18-8 nm. Consequently, the specific surface area of the nanocomposites ascends clearly with the increase of silica content, which is largely contributed by the increase in the thickness of the porous silica layer. The Ni_0.5Zn_0.5Fe₂O₄/SiO₂ nanocomposites demonstrate a better adsorption capability than the bare Ni_0.5Zn_0.5Fe₂O₄ nanoparticles for BSA. With the increase of the silica content from 0 to 0.05 and the specific surface area from about 49-57 m²/g, the BSA adsorption capability of the Ni_0.5Zn_0.5Fe₂O₄/SiO₂ nanocomposites calcined at 400 °C improve dramatically from 22 to 49 mg/g. However, with a further increase of the silica content from 0.05 to 0.2, the specific surface area increase from about 57-120 m²/g, the BSA adsorption for the nanocomposites remains around 49 mg/g, owing to the pores in the porous silica layer which are too small to let the BSA protein molecules in.     

Manufacturing Process of Nanostructured Alumina Coatings by Suspension Plasma Spraying

This paper describes the formation process of nanostructured alumina coatings and the injection system obtained by suspension plasma spraying (SPS), an alternative to the atmospheric plasma spraying technique in which the material feedstock is a suspension of the nanopowder to be sprayed. The nanoscale alumina powders (d ≈ 20 nm) were dispersed in distilled water or ethanol and injected by a peristaltic pump into plasma under atmospheric conditions. Optical microscopy (OM), scanning electron microscopy (SEM), and x-ray diffraction (XRD) analyses were performed to study the microstructure of the nanostructured alumina coatings. The results showed that the nanoscale alumina powders in suspension were very easily adsorbed at the inner surface of injection, which caused the needle to jam. The rotation of the pump had a great effect on the suspension injection in the plasma. The very small resistance of the thin plasma boundary layer near the substrate can drastically decrease the impacting velocity of nanosize droplets. The concentration of suspension also has a significant influence on the distribution of the size of the droplet, the enthalpy needed for spraying suspension, and the roughness of the coating surface. The phase structures of alumina suspension coatings strongly depend on the plasma spraying distance. A significant nanostructured fine alumina coating was obtained in some areas when ethanol was used as a solvent. The microstructures of the coating were observed as a function of the solvent and the spraying parameters.     

大气等离子喷涂TiO2涂层性能及厚涂层制备工艺

为改善TiO2溅射靶材主要依赖进口的局面,采用大气等离子喷涂技术在不锈钢SUS304平板基体及管状基体上制备了TiO2涂层。利用扫描电子显微镜对涂层形貌进行了观察,并对涂层与基体的结合强度、涂层孔隙率及抗热震性能分别进行了表征。结果表明：粉末熔化及铺展良好,截面可见典型层状结构。涂层与基体以机械结合为主,断裂基本发生在基体与粘结层界面处;涂层的孔隙率较低,同时具有良好的抗热震性能。厚涂层制备过程中,采用循环水冷却方法对不锈钢SUS304管状基体进行冷却,涂层沉积速度快且无开裂和脱落,涂层厚度可达8 mm。通过对冷却装置的改进及喷涂工艺的进一步优化,有望在大尺度管状基体上制备厚涂层以满足溅射蒸镀辊的需要。     

等离子喷涂Al2O3/TiO2复合粉末的Sol-Gel法制备

传统热喷涂粉末由小颗粒粉体混合团聚制得,流动性差、致密度低,制得的涂层均匀性差、性能不稳定。以有机金属盐为原料,采用溶胶-凝胶法及喷雾干燥法制备出氧化钛质量分数为13%的氧化铝-氧化钛(AT-13)复合前驱体粉末。采用TG-DSC、XRD、FESEM、霍尔流量计研究了粉体反应机理、物相组成、微观结构及流动性能,同时利用维氏硬度计、FESEM-EDS对制得的涂层性能进行了分析比较。结果表明,凝胶经喷雾干燥工艺后可获得球形Ti(OH)4/Al OOH复合粉体,直径约为40μm;与传统团聚粉体相比,前驱体粉末流动性更为优异,为43 s/50 g;由该粉末制得的涂层表面光滑、元素分布均匀、力学性能稳定、耐磨损性能优良,平均显微硬度达873.8 HV0.3,磨损量较团聚粉末涂层减少三分之一。     

等离子喷涂AlSi-ployester封严涂层工艺优化研究

采用AlSi-ployester粉末和PARXAIR-3710等离子喷涂系统制备封严涂层.为使AlSi-ployester等离子喷涂涂层获得优良的涂层性能,选择涂层结合强度为判据,通过正交试验对AlSi-ployester等离子喷涂工艺进行了优化.利用扫描电镜,Axio lmager.A lm金相图像分析系统等手段对涂层形貌和孔隙率进行分析,同时对涂层的硬度、抗热震性能进行了测试.确定优化后的工艺参数为:电弧电流790A.主气流量62.7 L/min,辅气流量5 L/min,喷涂距离100mm.结果表明,电弧电流、主气流量、辅气流量、喷涂距离对AlSi-ployester涂层结合强度具有不同的影响,在优化的喷涂工艺参数条件下,AlSi-ployester涂层结合强度可达6.9MPa,具有较好的硬度和热震性能,可为今后等离子喷涂系统工艺参数的选定提供参考.     

大气等离子喷涂Al2O3-40%TiO2涂层的组织与性能

为提高舰船关重部件的耐磨损、抗腐蚀性能,开展了大气等离子喷涂氧化铝复合涂层技术研究。在45钢表面制备Al2O3-40%TiO2陶瓷涂层,通过扫描电子显微镜、显微硬度计、电子天平、摩擦磨损试验机等仪器设备,分析该涂层的显微结构,测其显微硬度、孔隙率等性能,研究其在干摩擦条件下的摩擦磨损性能。结果表明:涂层均匀致密,孔隙率为1.86%,涂层与粘结层之间有明显的倒钩镶嵌结构;Al2O3-40%TiO2涂层的平均硬度为687.2 HV0.1,同时粘结层起到了硬度梯度作用;在干摩擦条件下,45钢主要为严重的黏着磨损,而涂层的磨损主要以层状剥离为主,伴随着少量磨粒磨损,且磨损量低于45钢。在某舰艇主机正时齿轮密封失效部位表面使用Al2O3-40%TiO2涂层,大大提高了正时齿轮的使用寿命,为舰船关重部件的维修与再制造提供了技术支持和理论参考。