钛合金表面激光熔覆镍-铬-硅复合涂层的显微组织和摩擦学性能

在Ti-5621s合金表面采用激光熔覆制备了镍-铬-硅复合涂层,分析了涂层的显微组织,测试了涂层的硬度和摩擦学性能.结果表明:复合涂层中以Ti5Si3和Cr3Si为主的颗粒增强相弥散分布在β-Ti和γ-Ni两相固溶体中;涂层的硬度较基体有显著的提高;由于金属硅化物Ti5Si3和Cr3Si的高硬度、强原子间结合力,该复合涂层明显地改善了基体合金的摩擦和磨损性能.     

纳米PTFE复合镀层的组织和摩擦性能

采用扫描电镜、透射电镜和X-射线衍射仪分析了纳米PTFE复合镀层的表面形貌和组织结构,利用微米划痕法在MXTX S/X型划痕试验仪上研究了纳米复合镀层的摩擦因数随PTFE含量变化的情况。研究结果表明:纳米PTFE的加入明显细化复合镀层。纳米PTFE以颗粒形式存在于镀层中。纳米复合镀层的摩擦因数明显低于未加纳米的镀层。当纳米PTFE的含量为15.0 g/L时,纳米复合镀层的摩擦因数最小(0.046)。     

不锈钢基体上激光熔覆原位合成制备TiB2/WC增强镍基复合涂层

采用激光熔覆原位合成技术在不锈钢基体表面制备了TiB2／WC增强镍基复合涂层,用X射线衍射仪、能谱仪、扫描电镜等对涂层进行了分析,并对涂层进行了热震试验。结果表明：涂层致密、厚度均匀、表面平整、无裂纹和孔隙、与基体呈冶金结合;涂层主要由TiB2、WC、γ-Ni等物相组成,细小的TiB2和WC粒子主要分布于γ-Ni枝晶间,可阻碍基体晶粒晶界的推移长大;WC颗粒主要分布于涂层中部和下部区域,原位合成的细小TiB2粒子主要分布于涂层上部;涂层具有较高的抗裂能力,与基体具有良好的结合强度。     

不锈钢基体上激光熔覆原位合成制备TiB_2/WC增强镍基复合涂层

采用激光熔覆原位合成技术在不锈钢基体表面制备了TiB2/WC增强镍基复合涂层,用X射线衍射仪、能谱仪、扫描电镜等对涂层进行了分析,并对涂层进行了热震试验。结果表明:涂层致密、厚度均匀、表面平整、无裂纹和孔隙、与基体呈冶金结合;涂层主要由TiB2、WC、γ-Ni等物相组成,细小的TiB2和WC粒子主要分布于γ-Ni枝晶间,可阻碍基体晶粒晶界的推移长大;WC颗粒主要分布于涂层中部和下部区域,原位合成的细小TiB2粒子主要分布于涂层上部;涂层具有较高的抗裂能力,与基体具有良好的结合强度。     

PTFE对复合镀层摩擦特性的影响

研究了PTFE添加量对Ni基电刷镀PTFE复合镀层的摩擦特性和磨损机制的影响.采用扫描电镜、X射线衍射仪和能谱仪分析了摩擦前后的磨损表面的形貌、组织和成分变化.结果表明:PTFE添加量对复合镀层的组织和摩擦特性有较大的影响.当PTFE体积分数为3%和4%时,复合镀层的摩擦因数最小;当PTFE体积分数为2%时,复合镀层的耐磨性最好.在磨损面上富含PTFE复合层的形成和面积随PTFE添加量的变化影响了复合镀层的摩擦特性及其磨损机制.     

Microstructure and Wear Properties of In Situ Synthesized VC Carbide Reinforced Fe-based Surface Composite Coating Produced by Laser Cladding

In situ synthesized VC carbide particles reinforced Fe-based composite coating was fabricated by laser cladding on steel substrate using ferrovanadium (Fe–V) alloy and graphite as the precursor powders. The phase structure and microstructure of the clad layer were investigated by means of X-ray diffraction analysis, scanning electron microscopy, and electron probe microanalysis. Results showed that uniformly distributed VC particles with the radial dendrites shape could be synthesized by the in situ reaction. The hardness and wear properties of the clad coatings were greatly improved due to the presence of VC particles in comparison with the substrate.     

火焰喷涂PA1010/n-SiO2复合涂层干摩擦磨损性能

利用火焰喷涂法制备PA1010/n-SiO2复合涂层,并采用均匀试验设计方法研究涂层在干摩擦条件下同GCr15 钢环配副时的摩擦学性能;利用SPSS 12.0统计软件对试验结果进行回归分析, 建立涂层摩擦系数和磨损质量损失同pv值 (摩擦载荷与摩擦速度的乘积)相关性的数学模型;利用示差扫描量热仪(Differential scanning calorimetry, DSC)和扫描电子显微镜(Scanning electron microscope, SEM)对复合涂层的热性能和磨损表面形貌进行分析。结果表明,n-SiO2的加入能明显提高涂层的结晶性能、耐磨性能。当n-SiO2含量为1.5%时,复合涂层摩擦磨损性能最佳,在试验条件下磨损质量损失降低近4倍,摩擦因数降低23％,跑合期缩短44％,复合涂层与GCr15钢环对磨时的磨损机理主要为疲劳磨损和轻微的粘附 磨损。     

Tribological Behavior of Bronze Composite Coatings Obtained by Plasma Thermal Spraying

Bronze aluminum composite coatings containing different amounts of alumina were fabricated by plasma spray process and their tribological properties were investigated using ball-on-disk (BOD) and rubber wheel (RW) tests at room temperature. Main wear mechanisms in pure bronze coatings during the ball-on-disk friction test were abrasion and intersplat delamination. The addition of alumina in bronze coatings clearly enhances their wear resistance. To explain this behavior, this article proposes an additional wear mechanism in the composite coatings that involves the rupture of the alumina lamellae located just below the wear track leading to a uniform distribution of fine alumina particles enveloped by the bronze matrix, which increase the surface hardness and hinder the wear. The deposition of debris on the wear track of composite coatings provokes an enhancement of the wear resistance as well. Bronze coatings show a low and stable friction coefficient of around μ = 0.3. Nevertheless, coatings with reinforcing particles of alumina show an abrupt transition in the friction coefficient from values around μ = 0.4–0.8, related to the modification of the surface contacts on the wear track due to the formation of a compacted debris layer deposited during the tribological test.     

镍基合金喷熔层摩擦学行为与机制的研究

采用热喷熔工艺制备了两种镍基合金喷熔层,并选用高锰钢、不锈钢作为对比材料,研究了镍基合金喷熔层的摩擦磨损性能。研究结果表明：镍基合金喷熔层具有良好的耐磨损性能和较低的摩擦系数。镍含量对喷熔层的摩擦学性能有显著影响,高镍含量的镍基合金,其耐磨性能明显优于低镍含量的镍基合金。在低速轻载条件下,镍基合金喷熔层的磨损机理为微观犁削;高速重载时,表现为粘着磨损和磨料磨损,其中高镍含量的喷熔层表面形成了致密的转移膜,有效地降低了磨损率。     

有机钼复合添加剂摩擦磨损性能的研究

以合成的有机钼与碱性石油磺酸钙按一定的配比，制备了复合添加剂加入到基础润滑油中，在四球摩擦试验机上测试了其摩擦磨损性能。结果表明，这种复合添加剂可使基础油的摩擦系数显著降低，可较大地提高基础油的承载能力和抗磨损性能，并有效地抑制温升。     

Ni/GO复合镀层的制备与摩擦学性能研究

基于修正的Hummers法制备了GO颗粒,并对其进行了XRD、FT-IR、SEM和TEM表征;利用电沉积技术在铜基体上制备了Ni/GO复合镀层,通过改变镀液中GO的浓度研究其对复合镀层摩擦磨损性能的影响。结果表明,相比于纯Ni镀层,复合镀层的摩擦磨损性能有了很大的提高。     

激光熔覆Zr基涂层的组织性能研究

在纯Ti(TA2)基体上分别激光熔覆Zr65Al7．5Ni10Cu17．5和Zr65Al7．5Nil0Cu17．5 0．8％C合金粉末，对涂层进行了X射线衍射分析、SEM观察和TEM分析，可知涂层由金属间化合物(其中包括纳米晶)和少量的非晶组成。这种具有高比强度、高硬度和高抗氧化性的金属间化合物与非晶相混合的复合涂层具有较好的性能，两种涂层的最高硬度分别达到1114．4HK和977．8HK。     

Microstructure Development and Tribological Behavior in AlCuFe Quasicrystalline Thin Films

A series of AlCuFe films were deposited by magnetron sputtering and subjected to X-ray diffraction and tribological testing to elucidate the correlation between quasicrystalline phase content and coefficient of friction. The sputter target was a pressed powder target comprised of a mixture of elemental powders combined in the ratio Al₆₅Cu₂₃Fe₁₂ and pressed at 400°C. This target was designed to produce film compositions within the single-phase icosohedral quasicrystalline regime. X-ray diffraction performed on the as-deposited coatings showed that they were comprised of a nanoscale/amorphous precursor phase with broad X-ray diffraction maxima. Anneals of the as-deposited films were performed at 450 or 500°C in argon for various times to cause partial or full development of the quasicrystalline microstructure, and films were tribo-tested in two separate systems. The first of these was an oscillating pin-on-flat system, in which a coated 2 mm diameter pin was used to test as-deposited films at temperatures of up to 220°C under vacuum and a 15 g load. The second system used a 0.25 diameter alumina ball and a load of 100 g to test films in air at temperatures of 25, 150, and 300°C. Various anneal conditions were also tested. For an as-deposited coating, a coating annealed for 2 h at 450°C, and a coating annealed for 1h at 500°C, the observed coefficients of friction were 0.45, 0.23, and 0.17, respectively. Correlation between quasicrystalline phase content, room temperature friction coefficient, and appearance of the wear track clearly showed that annealing to the fully developed quasicrystalline structure resulted in a harder film with a lower coefficient of friction.     

MoS_2-Zr复合薄膜的摩擦磨损特性研究

采用中频磁控溅射技术及多弧离子镀相结合的复合镀膜工艺,在硬质合金YT14基体上制备了MoS2-Zr复合薄膜.采用扫描电子显微镜(SEM)观察了MoS2-Zr复合薄膜表面及截面形貌,利用多功能材料表面性能试验仪测试了薄膜的厚度、结合力,利用显微硬度计测试薄膜的显微硬度,在高速环块磨损试验机进行了摩擦磨损试验,并分析了薄膜的摩擦磨损机制.结果表明:制备的MoS2-Zr复合薄膜结构致密,薄膜的厚度、结合力、显微硬度等性能参数明显优于MoS2薄膜,摩擦磨损性能有较大改善.薄膜的摩擦磨损过程主要是薄膜的剥落和转移的过程,复合薄膜由于结合力和硬度的提高,能够延缓薄膜的剥落及转移,降低薄膜的磨损率,提高薄膜的摩擦磨损特性,延长薄膜的作用时间.     

Influence of Heat Treatment on Microstructure and Sliding Wear of Thermally Sprayed Fe-Based Metallic Glass Coatings

Fe₆₂Ni₃Cr₄Mo₂W₃Si₆B₁₇C₃ amorphous coatings were thermally sprayed by a high velocity oxygen fuel spraying system (DJ-2700) and heat-treated at the temperatures ranges from 873 to 1,173 K in vacuum for 1 h. Differential scanning calorimetry, X-ray diffraction (XRD), and scanning electron microscopy were used to study the microstructural characteristics of the coatings. Vickers hardness tester was used to measure the hardness of the coatings. At the same time, the sliding wear behavior of the coatings was evaluated in a reciprocating ball-on-disk system. Within the resolution of XRD, amorphous structure without apparent crystalline phases was obtained in the as-sprayed coating. The heat treatments above 873 K led to the crystallization of amorphous phase. With the increase of heat treatment temperature, diffusion and sintering could occur between the layers of the coatings. The highest microhardness was obtained in the coating heat-treated at 973 K. When wear tested at a relative low load of 2 N, a direct correlation between the hardness and wear resistance of the coatings seems to be reasonable. However, at relative high loads, the wear resistance of the coatings is dependent on the resistance to crack initiation and growth between the layers rather than the hardness.     

超声电沉积镍/纳米碳化硅复合镀层组织结构研究

采用超声电沉积方法在20钢基体上制备了镍／纳米碳化硅的复合镀层。通过扫描电镜(SEM)观察了镀层的表面形貌和显微组织，用能谱仪(EDS)对镀层中特定区域进行了显微组织成分分析，使用X射线衍射仪检测了镀层的微观结构。结果表明：通过合适的超声电沉积工艺，得到的镀层中SiC纳米粒子含量较高，且分散均匀，没有出现团聚现象；同时镀层中的镍晶粒得到了细化，取向也由择尤取向趋于随机取向。     

Microstructure,Physical Properties,and Tribological Characteristics of Composite Solid Lubricant Coatings with Gas Atomized BaF2-CaF2

PS304 is a NASA-developed composite solid lubricant for friction and wear reduction at high temperatures. The microstructure, physical properties, and tribological performance of PS304 using standard comminuted BaF₂-CaF₂ and novel gas atomized BaF₂-CaF₂ were compared. Two atomized BaF₂-CaF₂ particle size distributions were used. Overall, feedstock powder with atomized BaF₂-CaF₂ flowed more freely than standard PS304 feedstock. The cohesion strength of coatings with atomized BaF₂-CaF₂ was lower than that of standard PS304, while the hardness of all of the studied coatings was essentially the same (approximately 58 HRA). Pin wear was lower against the new coatings and the coefficients of friction were essentially the same for all coatings. These results indicate that atomized BaF₂-CaF₂ can be substituted for comminuted BaF₂-CaF₂, providing a high-volume BaF₂-CaF₂ fabrication technique to reduce the cost of PS304 and improve its commercial availability.     

纳米粒子对Ni-Ti复合镀层摩擦学特性的影响

用化学复合镀方法制备含碳纳米管(CNTs)和纳米稀土氧化物Ni-Ti纳米复合镀层,研究纳米粒子含量对纳米复合镀层摩擦磨损性能的影响,并用扫描电子显微镜SEM对纳米镀层进行分析,并测定纳米复合镀层的显微硬度,利用AES能谱分析其磨损机制。结果表明:随着纳米粒子含量的增加,纳米复合镀层的显微硬度增加,摩擦因数降低,耐磨性能提高;质量分数为1.5%的纳米复合镀层的摩擦因数最低,并显示优良的耐磨性能。     

石墨烯/MoS2复合涂层多环境下的摩擦学性能

以MoS2作为润滑剂,以石墨烯(GE)作为润滑添加剂,采用喷涂法在GCr15钢样片表面制备不同含量的GE/MoS2复合涂层.利用HSR-2M型高速往复式摩擦磨损试验机测试涂层在干摩擦及海水环境中的摩擦磨损性能,并分析了磨痕形貌及磨损机制.结果表明:添加适量石墨烯可明显改善MoS2涂层的摩擦磨损性能,且海水环境中涂层的摩...     

射频磁控溅射WS2 -Ag复合薄膜的组织结构及环境摩擦磨损特性

采用射频磁控溅射方法在高速钢基体上制备WS2-Ag复合薄膜.用能谱(EDS)、X射线衍射(XRD)、扫描电镜(SEM)等对薄膜的成分、组织结构和形貌进行了表征;用划痕仪和球-盘式摩擦仪分别测试薄膜的结合力和大气及真空环境下的摩擦学性能.结果表明,Ag含量为3.23%～5.78%的WS2-Ag复合薄膜具有非晶态结构.Ag的掺入可使WS2薄膜平滑、致密,提高薄膜与基体的结合力,降低薄膜的摩擦因数和摩擦学特性环境敏感性.复合薄膜的耐磨性比纯WS2更加优异,Ag含量5.05%的复合薄膜具有最佳摩擦学性能,其在大气和真空中的磨损率分别为1.06×10-6和0.72×10-6 mm3/(N·m).