铁基非晶合金增强碳化钨基涂层的结构和性能（英文）

采用超音速火焰喷涂(HVDF)技术制备了WC-CoCr/铁基非晶复合涂层。比较研究了复合涂层和WC-CoCr的微观形貌、硬度、耐磨性能、高温氧化性能和腐蚀性能。XRD分析和SEM观察表明,复合涂层主要由WC相、W_2C相和铁基非晶相组成。与WC-CoCr涂层相比,复合涂层的硬度有所降低,但是两者没有显著性差异。由于硬度下降,导致复合涂层的耐磨性能略低于WCCoCr涂层。800℃高温氧化测试表明,复合涂层在800℃具有良好的热稳定性,这归因于氧化过程中生成了一层致密的氧化膜。此外,复合涂层在3.5%氯化钠溶液中的耐腐蚀性能也优于WC-CoCr涂层。     

热处理对铁基非晶合金涂层相组成及磨损性能的影响

采用超音速火焰喷涂技术在0Cr13Ni5Mo不锈钢基体上制备了铁基非晶涂层,研究了500%～800℃不同温度热处理对涂层的相组成和摩擦磨损性能的影响.从涂层的显微硬度分析、相组成分析、晶粒大小分析、以及摩擦磨损试验分析表明:随着热处理温度升高涂层的相结构及性能发生变化,在600℃时,涂层中析出大量的纳米硬质相,涂层的显微硬度和耐磨损性能也随之大幅提高;涂层的显微硬度在600℃时达到最大,耐磨性能在750℃时最好.     

AlCrBN/AlCrSiN纳米晶多层复合涂层的制备及其性能

目的制备高硬度、高耐磨性、自润滑及高热稳定性的AlCrBN/AlCrSiN纳米晶多层复合涂层,探索涂层的微观结构、力学性能、耐磨性能及高温热稳定性能。方法采用多弧离子镀技术在WC-Co硬质合金以及不锈钢基底上,制备AlCrBN/AlCrSiN多层纳米晶复合涂层。采用扫描电子显微镜、X射线衍射、透射电子显微镜、纳米压痕仪等设备,对涂层在不同温度(600~1000℃)下退火前后的表面形貌、微观结构、力学性能、耐磨性能进行系统研究。结果AlCrSiN/AlCrBN涂层为典型的纳米晶复合多层结构,涂层主要由fcc-AlCrN纳米晶镶嵌在非晶的SiNx和BNx中并形成多层结构。涂层具有优异的热稳定性能,其结构能够保持到800℃不发生变化,当温度增加到900℃时,涂层发生调幅分解,形成c-AlN、hcp-AlN和Cr2N等复合结构,在1000℃退火后,涂层结构基本稳定,仍能检测到CrN相。涂层纳米硬度及平均摩擦因数分别为29.15 GPa和0.67。结论AlCrSiN/AlCrBN涂层具有优异的力学性能、耐磨性能及高温热稳定性能,在800℃以下保持稳定,在1000℃退火后仍能保持较高的硬度及良好的耐磨性能,在高速切削刀具中具有良好的应用前景。     

WC-CoCr涂层热震及高温抗氧化性能

采用超音速火焰喷涂技术在45钢表面制备了WC-CoCr涂层,在空气环境中对涂层进行高温氧化试验和热震试验,借助SEM、XRD和电子天平分别分析了涂层表面的微观形貌、氧化前后产物相组成及涂层增重。结果表明:HVOF制备的WC-CoCr金属涂层的组织致密、孔隙率低。该涂层经600℃静态空气氧化后,在涂层表面生成了CoWO_4、WO_3、Cr_2O_3等氧化产物,这些氧化物可阻止氧化的进一步发展,提高了涂层的抗氧化能力,涂层没有发生剥落。WC-CoCr涂层具有优异的抗氧化和热震性能。     

炭材料高温抗氧化莫来石/SiC复合涂层的制备及其1150℃高温抗氧化性能(英文)

采用化学气相反应及料浆刷涂烧结复合工艺在石墨表面制备高温抗氧化莫来石/SiC复合涂层。XRD物相分析结果显示涂层外层由莫来石及微量SiO2相组成,涂层内层主要由β-SiC相组成。通过高温抗氧化试验研究涂层的高温抗氧化行为并测试涂层氧化后的洛氏硬度。结果表明:所制备的莫来石/SiC复合涂层具有良好的高温抗氧化及热震性能,经过1150℃、109h的高温氧化及12次1150℃→室温的循环热震试验后,涂层试样的质量增加率为0.085%。硬度测试结果表明:所制备的莫来石/SiC复合涂层各层之间具有良好的结合性能。     

热处理对TiAlCN涂层组织和性能的影响

在Ar气条件下,对反应磁控溅射法制备的TiAlCN涂层进行500~1100℃热处理。采用XRD、Raman和DSC,研究不同热处理温度下涂层微观结构的变化,利用显微硬度计和划痕仪研究热处理对涂层性能的影响。结果表明,经600~800℃热处理后,涂层非晶碳相明显增加,使涂层形成纳米复合结构,这导致显微硬度显著增加,膜基结合性能增加;在900~1100℃热处理后,由于涂层中六方AlN相的析出,导致涂层显微硬度急剧下降,且韧性下降。     

高功率调制脉冲磁控溅射沉积TiAlSiN纳米复合涂层对钛合金基体抗氧化性能的影响研究

目的 研究Ti6Al4V基TiAlSiN涂层在800 ℃下的抗循环氧化性能。方法 采用高功率调制脉冲磁控溅射技术，通过调节N2/Ar的流量比fN2，在Ti6Al4V合金和Si(100)上沉积了一系列不同Si含量的TiAlSiN涂层。通过X射线衍射仪、扫描电子显微镜、电子探针、透射电镜和纳米压痕仪，表征了TiAlSiN涂层的成分、相组成、微结构和硬度，并通过X射线衍射仪和扫描电子显微镜，进一步对TiAlSiN涂层在800 ℃下循环氧化后的微观结构和形貌进行分析。结果 脉冲平均功率为2 kW时，fN2由10%增至30%，TiAlSiN涂层的Si含量(以原子数分数计)由6.1%增加至16.4%，涂层中Ti和Al含量则相应地降低。当fN2为10%时，TiAlSiN涂层呈现典型的X射线非晶结构特征，涂层中N含量(以原子数分数计)约为47%;当fN2为30%时，TiAlSiN涂层呈现TiAlN和非晶相的混合结构。TEM结果表明，涂层中TiAlN晶粒尺寸约为5 nm并均匀镶嵌在非晶相上。所有沉积于Si基底上的TiAlSiN涂层均具有相近的纳米硬度、弹性模量及残余应力，分别为17 GPa、225 GPa和–300 MPa。选取fN2为10%和25%，溅射具有不同氮含量和特征微结构的TiAlSiN涂层作为Ti6Al4V合金防护涂层，研究涂层的抗循环氧化性能。在800 ℃高温循环氧化70 h后，TiAlSiN涂层保护的合金样品较原始样品呈现更优异的抗氧化性能，且fN2为25%制备的高Si含量TiAlSiN涂层较fN2为10%制备的涂层具有更为优异的抗循环氧化性能。循环氧化后，TiAlSiN氧化层结构完整致密并呈现柱状晶特征，氧化层由上至下分别形成富α-Al2O3、a-TiO2及r-TiO2三层结构。结论 高Si含量的TiAlSiN涂层具有更低的氧化速率，涂层的纳米复合结构和低压缩应力是其抗循环氧化能力提高的主要原因。     

高温及氧化对WC-10Co4Cr涂层微观结构及性能的影响

采用X射线衍射仪(XRD)、扫描电镜(SEM)、显微硬度计、摩擦磨损试验机、冲蚀试验机等手段研究高温及氧化对超音速喷涂WC-10Co4Cr涂层的显微组织、显微硬度、结合强度、耐磨性能、耐冲蚀性能等的影响。结果表明:在空气中经600℃热处理后,涂层发生了明显的高温氧化,涂层中WC、Co、Cr相的含量降低,转化为Co WO_4、Cr_2O_5、C_6WO_6等氧化物相,孔隙率明显升高,结合强度有所降低,虽然涂层的显微硬度值有所提高,但耐磨损及耐冲蚀性能都明显降低;通过Ar保护,涂层只受到600℃的高温作用,涂层的相组成未发生明显改变,显微硬度有较大幅度的提高,且分布更加均匀,耐干摩擦磨损及耐泥沙冲蚀性能均获得大幅提高。     

沉积偏压对AlCrTiN纳米复合涂层力学与抗高温氧化性能的影响

沉积偏压对涂层的结构与性能具有重要影响,为研究其对AlCrTiN纳米复合涂层成分、组织结构、力学与抗高温氧化性能的影响规律,采用磁控溅射技术,改变沉积偏压(-30、-60、-90、-120 V)制备四种AlCrTiN纳米复合涂层。利用X射线衍射仪、扫描电子显微镜、纳米压痕仪等仪器表征涂层的组织结构、成分、力学性能和抗高温氧化性能。研究结果表明：不同偏压下制备的AlCrTiN纳米复合涂层均为NaCl型fcc-(Al,Cr,Ti)N相结构。随着沉积偏压增大,涂层由沿(111)晶面择优生长转变为无明显的择优生长取向,晶粒尺寸降低,残余应力和硬度增大。偏压为-90 V与-120 V时,涂层表面更加致密,具有更高的硬度和弹性模量。在800℃与900℃氧化1 h后,所有涂层表面均生成一层连续致密的Al₂O₃膜。随着沉积偏压增加,氧化膜厚度逐渐降低,表明抗高温氧化性能逐渐增强,这是因为高偏压下涂层组织更致密,且晶粒更细小。研究成果对AlCrTiN纳米复合涂层的综合性能提升与工程化应用具有一定指导意义。     

电弧离子镀偏压对TiAlSiN涂层结构及性能的影响

目的 探究脉冲偏压对TiAlSiN涂层结构及力学性能、耐磨性能、抗氧化性能的影响规律及机制。方法 采用阴极电弧离子镀膜技术，调控偏压参数并在M2高速钢上沉积TiAlSiN涂层，利用SEM、XRD、3D轮廓仪、金相显微镜、划痕仪、摩擦磨损试验仪等仪器及高温氧化试验，对涂层结构及性能进行分析表征。结果 偏压为50 V时，涂层主要为AlN相；偏压高于75 V时，涂层以固溶的(Ti,Al)N相为主，TiAlSiN涂层存在较强的(200)面择优取向。偏压由50 V增大至150 V时，涂层的致密性增加，表面粗糙度先降低后上升，涂层结合力先增大后降低。TiAlSiN涂层的磨损方式主要是磨粒磨损，受物相结构、涂层致密性的影响，偏压为100~150 V时，涂层的耐磨性能优异。涂层1000 ℃氧化4 h后，表面氧化程度不同，主要受物相结构、致密性、表面孔隙的多重影响，hcp-AlN相比(Ti,Al)N相更易氧化；偏压增大使得涂层沉积更为致密，氧化层深度变浅；涂层孔隙增加，表面形成的Al2O3团簇增多。结论 偏压100 V下TiAlSiN涂层的综合性能最优，涂层结合力为46.7 V，硬度为3276HV0.025，表面粗糙度最低，耐磨性能较好且高温下抗氧化性能最强。     

Tribocorrosion Behavior of Fe-Based Amorphous Composite Coating Reinforced by Al<Subscript>2</Subscript>O<Subscript>3</Subscript> in 3.5% NaCl Solution

Although corrosion and friction/wear behavior of Fe-based amorphous coatings and their composites has been extensively studied during the past decade, there is very limited work related to tribocorrosion behavior. In this paper, the tribocorrosion behavior of a Fe-based amorphous composite coating reinforced with 20 wt.% Al₂O₃ particles was investigated in a 3.5% NaCl solution on a ball-on-disk tester and was compared to the monolithic amorphous coating and 316L stainless steel (SS). The results showed that the amorphous composite coating exhibited the highest tribocorrosion resistance among the three materials tested, as evidenced by the lowest coefficient of friction (~0.3) and tribocorrosion wear rate (~1.2 × 10^?5 mm³/N·m). In addition, potentiodynamic polarization measurements before and during tribocorrosion testing demonstrated that corrosion resistance of the amorphous composite coating was not influenced so much by mechanical loading compared to the amorphous coating and the 316L SS. Observations on the worn surface revealed a corrosion-wear- and oxidational-wear-dominated tribocorrosion mechanism for the composite coatings. The excellent tribocorrosion resistance of the composite coating results from the effect of chemically stable Al₂O₃ phase which resists oxidation and delamination during sliding, along with poor wettability with corrosive NaCl droplets.     

纳米稀土CeO2掺杂对Ni-Fe-Co-P合金镀层性能的影响

利用喷射电沉积技术制备了Ni-Fe-Co-P-CeO_2复合镀层。通过SEM、XRD、EDS等测试了复合镀层的表面形貌、截面形貌、物相结构和组成成分,同时,表征了复合镀层的硬度、耐磨和耐蚀性能,探究和分析了纳米稀土CeO_2颗粒浓度对镀层性能的影响。结果表明:该多元复合镀层为非晶态结构;随着镀液中CeO_2颗粒浓度的增加,复合镀层的显微硬度、耐磨性和耐蚀性均呈先增强后减弱的趋势;镀液中CeO_2颗粒浓度为1 g/L时,复合镀层的表面均匀致密,其HV_(0.1)显微硬度达到最大值5982 MPa,且具有最优的耐磨和耐蚀性能。     

等离子喷涂Fe-基非晶复合涂层的磨损和腐蚀机制的研究

本文采用一种新型的气体多通道送粉等离子喷涂技术制备得到了含有不同质量分数的ZrO₂/Fe基非晶复合涂层。采用该技术可成功制得ZrO₂颗粒均匀分布于非晶基体的复合涂层,且可实现第二相颗粒的比例调控。磨损实验表明,复合涂层的磨损性能较单一的Fe基涂层有了很大提高。同时,ZrO₂颗粒的添加可提高耐蚀性能降低孔隙率。经实验表明,复合涂层的最佳耐蚀性能为ZrO₂含量50%。     

活性燃烧高速燃气喷涂WC-CoCr涂层的微观组织及性能

利用活性燃烧高速燃气(AC-HVAF)喷涂技术在0Cr13Ni5Mo不锈钢表面制备了WC-CoCr涂层,并利用XRD、SEM、滑动磨损以及电化学试验分析了涂层的微观组织以及耐磨耐蚀性.结果表明,涂层具有优异的微观结构以及良好的耐磨耐蚀性.XRD分析未发现其他喷涂技术普遍存在的W2C以及W相,AC-HAVF喷涂技术可以有效抑制WC的分解;涂层致密且与基体结合良好,孔隙率仅为0.75%.滑动磨损试验表明,涂层具有很低的磨损率.其主要原因为涂层硬度极高、WC颗粒细小和没有W2C相.电化学试验表明,WC-CoCr涂层的耐蚀性优于基体0Cr13Ni5Mo不锈钢,Cr的加入、W的缺少以及孔隙率低是WC-CoCr涂层耐蚀性优异的重要原因.     

Laser surface coating of Fe-Cr-Mo-Y-B-C bulk metallic glass composition on AISI 4140 steel

Fe-based bulk metallic glasses exhibit very high hardness, elastic modulus/limit and wear/corrosion resistance. In the present investigation, an attempt has been made to develop an amorphous coating with Fe₄₈Cr₁₅Mo₁₄Y₂C₁₅B₆ bulk metallic glass on AISI 4140 substrate by laser surface processing. Following coating, the microstructure and phase aggregate were analyzed by scanning electron microscope and X-ray diffraction, respectively. Microhardness and wear resistance were assessed using Vickers microhardness tester and ball-on-plate wear testing machine, respectively. The coating thickness varied directly with incident laser power and interaction time. Despite trials with wide range of process parameters, the present experiments were unable to retain complete amorphous surface microstructure after laser surface coating. Numerical prediction of the thermal profile and related parameters suggest that the cooling rate and thermal gradient experienced by the coated zone were fairly high. Yet failure to retain amorphous/glassy microstructure of an otherwise bulk metallic glassy alloy suggests that compositional changes (solute redistribution) within the coated zone and across the coating-substrate interface are responsible for nucleation and growth of crystalline phases from the melt. However, correlation between coating parameters and surface microstructure and properties allowed determination of the optimum conditions that ensured fine grained uniform microstructure with a significant improvement in hardness and wear resistance.     

电火花沉积 Fe 基涂层的组织及耐磨性能

通过电火花沉积技术在P20模具钢表面制备了Fe基涂层,利用SEM,XRD及摩擦磨损试验机等分析了涂层的组织结构、显微硬度及耐磨性能。结果表明:电火花沉积Fe基涂层组织均匀、致密;涂层中靠近界面处的组织为柱状枝晶,而涂层中上部组织为超细晶粒。涂层的平均硬度为637.1HV0.1,相比基体提高了1倍;涂层耐磨性优于基体,涂层中弥散分布的Cr7C3,CrB及Fe3C等硬质是Fe基涂层硬度及耐磨性提高的主要原因。涂层的磨损机理主要为磨粒磨损的微切削和疲劳磨损。     

电子束熔覆WC-CoCr涂层的表面结构以及耐磨性

镍基合金在含氯介质中有着优异的耐蚀性能,但其耐磨性不足。本文首先利用HVOF在Inconel617基体上沉积WC--CoCr涂层,研究了经过电子束重熔获得新的改性层表面形貌以及相成分。电子束处理后,一些喷涂层的结构缺陷得到了改善,涂层空隙减少,晶粒得到了细化,由于生成了高硬度的新相（尤其是Co6W6C相）,熔覆层的显微硬度为1100HV0.3,为基体显微硬度（550HV0.3）的两倍。通过摩擦磨损实验分析,试样相比于基体的滑动磨损行为,其磨损率有着显著的降低,而EDS分析表明,熔覆层内出现了新的元素,基体与涂层达到了良好的冶金结合。此外,熔覆层在盐水中的抗腐蚀能力有所提高。     

Fabrication and Characterization of Thermal-Sprayed Fe-Based Amorphous/Nanocrystalline Composite Coatings: An Overview

This review focuses on the recent development of iron (Fe)-based amorphous/nanocrystalline composite coatings, which have attracted much attention due to their attractive combination of high hardness/strength, elevated abrasive wear resistance, and enhanced corrosion resistance. Accompanying the advancements in various thermal spray technologies, industrial application fields of Fe-based amorphous/nanocrystalline composite coatings are becoming more diverse. In the main part, the typical empirical rules for the design of amorphous alloys with high glass-forming ability are generalized and discussed at first. Then various thermal spray technologies for the fabrication of Fe-based amorphous/nanocrystalline composite coatings, such as high velocity oxygen/air spray (HVOF/HVAF), air plasma spray (APS), low-pressure plasma spray (LPPS), high-energy plasma spray (HPS), and high velocity arc spray (HVAS) processes, are introduced. The microstructures, hardness, wear resistance, and corrosion resistance of Fe-based amorphous/nanocrystalline composite coatings formed using these thermal spray technologies are reviewed and compared. Finally, the existing challenges and future prospects are proposed.     

Electroless deposition of Ni-P composite coatings containing kaolin nanoparticles

Abstract

The ability to codeposit particulate matter in a matrix of electroless nickel has led to a new generation of composite coatings with unique properties, such as high hardness wear, abrasion, corrosion and high temperature oxidation resistance. In this paper, the authors report on the development of electroless Ni–P–kaolin composite coating, and the characteristic properties of the selected deposits were evaluated by scanning electron microscopy, energy dispersive X-ray and X-ray diffraction techniques. A good rate of deposition of 12 μm h^?1 was observed for the optimised concentration of 6 g L^?1 of kaolin in the bath. For the optimised bath composition and operating conditions, the composite deposit was found to contain 81·7%Ni, 9·8%P and 10·5%kaolin. Heat treatment at 400°C for 1 h results in an increase in the hardness and wear resistance of the composite coating. The corrosion resistance is also highly enhanced by the incorporation of kaolin in the nickel–phosphorus matrix. The crystallite size of the composite coating is 20 nm, and the codeposition of kaolin follows the Langmuir adsorption isotherm.     

煤油流量对HVOF铁基非晶涂层组织与性能的影响

以工业原材料制备的FeCoCrMoCBY非晶粉末为喷涂材料,采用超音速火焰喷涂(HVOF)制备铁基非晶合金涂层。通过X射线衍射仪(XRD)、差示扫描热仪(DSC)、扫描电子显微镜(SEM)、维氏显微硬度计等测试方法,探讨煤油流量对涂层显微组织、微观结构及显微硬度的影响,并分析涂层与316 L不锈钢在1 mol/L HCl溶液中的动态极化特征。结果表明:涂层与基体结合良好,呈现典型的层状结构,非晶含量高,表现出比316 L不锈钢更高的耐腐蚀性能。其它参数一定时,煤油流量越高,涂层致密度越高,非晶含量先增多后减少,显微硬度先增大后减小;当氧气流量为50 m~3/L,煤油流量为26 L/h时,涂层非晶含量最高,为99.4%,孔隙率为1.51%,自腐蚀电流密度低,为5.62×10~(-6) A/cm~2,自腐蚀电位为-0.36 V,耐腐蚀性能表现最佳。