Cu-Cr纳米金属多层膜屈服强度/硬度的尺寸依赖性

采用磁控溅射方法分别在聚酰亚胺基体以及单晶硅基体上制备恒定调制比(η)以及恒定调制周期(λ)的Cu-Cr纳米金属多层膜;通过单轴拉伸试验以及纳米压痕试验系统研究Cu-Cr多层膜屈服强度及硬度的尺度依赖性。微观分析结果表明:基体对多层膜的微观结构无影响,Cu-Cr多层膜在生长方向上均呈现Kurdjumov-Sachs取向关系,即{111}Cu//{110}Cr和-110-Cu//-111-Cr。力学测试结果表明:调制比恒定的Cu-Cr多层膜的屈服强度及硬度随调制周期的缩短而增加;调制周期恒定的Cu-Cr多层膜的屈服强度/硬度随调制比的增加而增加。Cu-Cr多层膜变形机制在临界调制周期(λc≈25 nm)和临界调制比(ηc≈1)由Cu层内单根位错滑移转变为负载效应。     

调制周期对CrAlN/ZrN纳米多层膜韧性的影响

目的研究调制周期对纳米多层膜性能的影响。方法采用磁控溅射方法制备了CrAlN与ZrN的固定厚度比为2.6,不同调制周期(Λ为6,8,10,20 nm)的CrAlN/ZrN纳米多层膜。利用场发射扫描电镜(FESEM)表征薄膜的形貌、结构。用Dektak150型台阶仪测薄膜表面粗糙度。用Agilent Technologies G200纳米压痕仪检测涂层的硬度和弹性模量。用划痕仪测薄膜/基材的结合力,同时,引入抗裂纹扩展系数(CPR)表征纳米多层膜的韧性。结果 CrAlN/ZrN纳米多层膜断面皆为穿晶柱状结构,调制周期为20 nm时,多层膜层与层之间的界面清晰;多层膜表面呈致密的花椰菜状,厚度均约为2μm。调制周期为8 nm时,硬度为20.4 GPa,进一步增大调制周期,硬度下降。调制周期为8 nm的多层膜临界载荷L_(c2)为18 N,CPR值为73.2,L_(c2)与CPR值均高于其他调制周期的多层膜。在临界载荷L_(c2)处,裂纹扩展导致薄膜发生了严重的片状剥落,露出了亮白的热轧钢基底,薄膜失去了保护作用。结论实验表明,在多层膜厚度、调制比不变的条件下,改变调制周期能够改变多层膜的韧性。随着调制周期的增大,韧性呈先上升、后下降的趋势。调制周期为8 nm时,纳米多层膜的硬度最高,韧性最好,综合性能良好。     

调制周期对Cr/CrN纳米多层膜的结构与性能的影响

采用多弧离子镀技术在65Mn钢表面制备了不同调制周期的Cr/CrN纳米多层膜.采用俄歇能谱仪(AES)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、纳米硬度仪、轮廓仪和划痕仪,分析了不同调制周期Cr/CrN纳米多层膜的成分分布、微观结构、力学性能、残余应力和结合强度.结果表明,Cr/CrN纳米多层膜的表面平整致密,截面层状调制结构清晰,其调制结构为Cr层-过渡层-CrN层的"三明治"结构,调制比约为1∶ 1.多层膜由CrN、Cr2N和Cr相组成,在CrN(200)方向上出现择优取向.当调制周期为80 nm时,多层膜的硬度值相对较高.随调制周期的增大,Cr/CrN多层膜的残余应力值减小,结合强度值先增大后减小.当调制周期为120 nm时,涂层的划痕临界载荷值相对较高,为69 N.     

非对称双极脉冲反应磁控溅射制备TiN/ZrN多层膜

采用非对称双极脉冲磁控溅射制备了一系列不同调制周期的TiN/ZrN纳米多层膜,利用X射线衍射分析(XRD)、纳米压痕仪、扫描电子显微镜(SEM)表征了薄膜的微观结构、力学性能和断口形貌.结果表明,在调制周期为30 nm时,纳米硬度达到38 GPa.     

调制周期对Ti/TiB_2多层膜的结构和力学性能的影响

采用磁控溅射法制备了Ti/TiB_2周期性(T=2,3,4,6,12)多层膜,利用X射线衍射仪、场发射扫描电子显微镜分析了薄膜的相结构和表面(断面)形貌,采用纳米压痕仪、多功能摩擦摩损试验机和显微硬度计研究了多层膜的纳米硬度、弹性模量、膜基结合力以及断裂韧性。结果表明:Ti/TiB_2多层膜具有清晰的纳米层状结构,薄膜表面致密平整,与基体保持着良好的物理结合。多层膜的硬度和弹性模量随着调制周期的增加而增大,在周期T=12时,多层膜的硬度和弹性模量达到最大值,分别为35.8和349 GPa;多层膜的断裂韧性随着周期的增加呈现出先增大而后减小的趋势,当周期T=6时多层膜的断裂韧性最好,其断裂韧度为2.17 MPa·m~(1/2)。分析认为多层膜中的Ti子层可使裂纹尖端产生钝化作用,从而引起裂纹扩展路径发生偏转,提高了多层膜的断裂韧性。     

调制周期对磁控溅射WB2/CrN多层薄膜力学性能的影响

目的研究调制周期对磁控溅射WB_2/CrN多层膜结构及性能的影响。方法通过双靶直流磁控溅射法,在硅片、石英玻璃片及不锈钢上,制备Al B_2型WB_2薄膜与CrN薄膜及其多层复合薄膜,采用X射线衍射及扫描电子显微镜对其相结构及形貌进行观察和分析,使用维氏显微硬度仪及划痕仪对多层膜的硬度及膜基结合力进行研究。结果磁控溅射WB_2/CrN多层薄膜呈现出柱状生长趋势,且层状结构明显,仅当调制周期大于317 nm时,多层膜中才出现WB_2晶体的衍射峰。结论多层膜中的WB_2薄膜在本实验条件下的临界结晶厚度大于150 nm。随着调制周期的减小,CrN层生长取向发生由(200)晶面向多晶面的转变,WB_2层生长取向由(101)晶面向(001)晶面转变。多层膜硬度随调制周期的减小大体呈下降趋势,在调制周期为317 nm时达到最大值。结合力变化趋势与硬度相反,CrN层及多层界面有助于复合薄膜膜基结合强度的提高。     

调制结构对TiN/TaN多层膜的生长行为及力学性能的影响

利用反应磁控溅射方法，制备了调制周期相同而调制比不同的TiN／TaN多层膜．利用XRD，HRTEM和纳米压痕仪分别对多层膜的结构、微观状态和力学性能进行了系统研究．结果表明：调制结构不仅改变多层膜的生长速率，而且能导致多层膜择优生长取向的变化；界面应力的存在使得薄膜生长速率随沉积层厚度的增加而下降；在TiN／TaN多层膜中存在着各自独立外延生长的[111]和[100]两种取向的调制结构，且具有不同的调制周期；调制周期为6nm左右的TiN／TaN多层膜的硬度与弹性模量分别提高约50％与30％；在调制比为3：1时，硬度最大值为34．2GPa，弹性模量为344．9GPa；根据结构和力学性能的分析结果，讨论了TiN／TaN多层膜的硬化机制．     

TiAlN/CrAlN纳米结构多层膜的结构与性能

采用射频磁控溅射方法制备了单层TiAlN、CrAlN复合薄膜以及不同调制周期和不同层厚比(lTiAlN/lCrAlN)的TiAlN/CrAlN纳米结构多层膜.薄膜采用X射线衍射仪、扫描电子显微镜、显微硬度仪进行表征.结果表明:TiAlN、CrAlN复合薄膜和TiAlN/CrAlN多层膜均为面心立方结构,呈(111)面择优取向.TiAlN/CrAlN多层膜的择优取向与调制周期和层厚比无关.层厚比为1的TiAlN/CrAlN多层膜的硬度依赖于调制周期,在调制周期为8 nm时,达到最大;固定TiAlN的厚度为4 nm,改变CrAlN层的厚度,在研究范围内,多层膜的硬度随着CrAlN层厚度的增加而增加.探讨了多层膜的致硬机制.TiAlN/CrAlN多层膜抗氧化温度比其组成单层膜高了近200 ℃,并讨论了其抗氧化机制.     

离子束增强沉积Ti–Mo多层膜和TiMo合金膜及其性能

采用离子束增强磁控溅射沉积技术制备了Ti-Mo金属多层膜和TiMo合金膜,评价了膜层的结合强度、韧性、硬度等力学性能和摩擦学性能.结果表明:不同调制周期及不同调制比的Ti-Mo多层膜的硬度均比Ti、Mo金属单层膜的硬度高,调制周期小于200 nm的多层膜呈现出明显的超硬度现象,调制周期为20 nm的多层膜硬度达到最大值,多层膜硬度随Ti膜:Mo膜调制比的减小而提高.Mo过渡层比Ti过渡层更能有效改善膜层的结合强度,离子辅助轰击能明显提高膜层的结合力.TiMo合金膜的硬度与Mo金属单层膜相近,明显低于调制周期20～200 nm的Ti-Mo多层膜,其韧性也明显低于调制周期60 nm以上的Ti-Mo多层膜.调制周期20～200 nm的Ti-Mo多层膜的耐磨性能优于TiMo合金膜.     

纳米调制周期对CrWN/MoN纳米多层涂层结构和性能的影响

目的 研究纳米调制周期对CrWN/MoN纳米多层涂层结构及性能的影响。方法 采用电磁永磁共控的阴极电弧离子镀技术，使用纯N2和合金CrW靶及纯金属Mo靶，制备不同调制周期厚度的CrWN/MoN纳米多层涂层，对CrWN/MoN纳米多层涂层的物相结构、微观形貌、硬度、摩擦系数和磨损率等进行分析。结果 CrWN/MoN纳米多层涂层由面心立方CrWN与六方d-MoN两相组成。随着调制周期减小，CrWN/MoN纳米多层涂层衍射峰强度逐渐减弱，d-MoN(202)衍射峰消失，涂层表面的大颗粒数量减少，表面质量得到改善。随着调制周期由45 nm减小到13 nm，涂层的硬度由29.4 GPa逐渐减小到25.5 GPa，当调制周期为8 nm时，CrWN/MoN纳米多层涂层硬度与弹性模量均达到最大值，分别为30.2 GPa和354.6 GPa。随着调制周期的减小，CrWN/MoN纳米多层涂层平均摩擦系数由0.45逐渐减小到0.29，磨损速率由4.2×10^?7 mm³/(N.m)逐渐减小到3.3×10^?7 mm³/(N.m)。结论 调制周期对CrWN/MoN纳米多层涂层性能影响较大，调制周期厚度为8 nm时，CrWN/MoN纳米多层涂层的硬度最大，耐磨性能最好。     

Characterization and wear properties of nanoscaled TiN/TaN multilayer coatings

The structural, morphological, mechanical and tribological characterization of nanoscaled multilayer TiN/TaN coatings deposited by magnetron sputtering technology were investigated by low angle X-ray diffractometry, high angle X-ray diffractometry, atomic force microscopy, microhardness, pin-on-disc testing and 3-D surface profiler. The results show that the TiN/TaN coatings exhibit good modulation period and sharp interface between TiN and TaN layers. In mutilayered TiN/TaN coatings, TiN layers have cubic structure, but hexagonal structure emerged among TaN layers besides cubic structure as modulation period is beyond 8.5 nm. The mierohardness is affected by modulation period and the maximum hardness value of 31.5 GPa appears at a modulation period of 8.5 rim. The coefficient of friction is high and the wear resistance is improved for TiN/TaN coatings compared with those of TiN coating; the wear mechanism exhibits predominantly ploughing, material transfer and localized spallation.     

Synthesis of nanoscale multilayered ZrN/W2N multilayered coatings by magnetron sputtering

ZrN/W₂N multilayered coatings with nanoscale modulation period in an ultra-high vacuum rf magnetron sputter chamber. XRD, SEM, Nano Indenter and profiler were employed to investigate the influence of modulation periods and working pressures on structural and mechanical properties of the coatings. The low-angle XRD pattern and cross-sectional SEM indicated a well-defined composition modulation and layer structure of the multilayered coating. All multilayered coatings revealed higher hardness than the rule-of-mixtures value of monolithic ZrN and W₂N coatings at different working pressures. The maximum hardness was up to 34 GPa. The multilayers obtained mixed polycrystalline textures of ZrN(111), W₂N(111), W₂N(200) and W₂N(311). 0.8 Pa was an optimum working pressure for mechanical property enhancement.     

Effects of TaN nanoparticles on microstructure,mechanical properties and tribological performance of PEEK coating prepared by electrophoretic deposition

In order to solve the friction, wear and lubrication problems of titanium, a series of TaN/ployether- ether-ketone (PEEK) coatings were developed by electrophoretic deposition, and the effects of TaN nanoparticles on the microstructure, mechanical properties and tribological performance of coatings were explored. Results manifest that the introduction of TaN nanoparticles into PEEK coatings could improve the deposition efficiency, enhance the resistant deform capacity, increase the hardness, elastic modulus and adhesive bonding strength. Compared with the pure PEEK coating, the friction coefficient of P-TN-3 was greatly reduced by 31.25%. The wear resistance of P-TN-3 was also improved in huge boost, and its specific wear rate was decreased from 9.42×10^-5 to 1.62×10^-5 mm³·N^-1·m^-1. The homogeneous composite TaN/PEEK coatings prepared by electrophoretic deposition were well-adhered to the titanium alloy substrate, TaN nanoparticles could improve the strength of PEEK coating, and provide wear-resistance protection for titanium alloys.     

Structure and properties of cathodic vacuum arc deposited NbN and NbN-based multi-component and multi-layer coatings

Binary Nb-N coatings, ternary Ti-Nb-N and Zr-Nb-N, and multi-layer TiN/NbN coatings consisting of up to 100 alternating TiN and NbN layers, were deposited onto WC-Co substrates, using two different vacuum arc deposition (VAD) systems: with and without magnetic guiding of the metal plasma flow. Binary Nb-N coatings were fabricated by deposition of metal plasma produced by a Nb cathode in a background of reactive nitrogen gas at different pressures, P. Ternary coatings were fabricated at co-deposition of plasmas originating from two different cathode materials. Multilayer coatings were fabricated by alternatively depositing plasmas of Ti and Nb in reactive nitrogen gas. The crystalline coating structure, phase composition, hardness and critical load for coating failure were studied.For binary Nb-N coatings fabricated using both deposition systems, the phase composition, the Vickers hardness, HV, and the critical load strongly depended on the deposition pressure. Using VAD with magnetic plasma guiding, the highest HV of ∼ 42 GPa was measured for coatings deposited at low nitrogen pressure. These coatings contained a hexagonal β-Nb₂N phase and had a relatively low critical load. The highest critical load and HV ∼ 38 GPa were obtained for coatings consisted of a single phase NaCl-type cubic δ-NbN structure, deposited at a higher nitrogen pressure. The structure and properties of Nb-N coatings deposited using VAD without magnetic plasma guiding had a similar correlation with the deposition pressure, however, their hardness values were lower.Ternary Ti-Nb-N and Zr-Nb-N coatings fabricated by both deposition processes had a single phase cubic NaCl-type structure and the hardness higher than that of the binary nitrides TiN, ZrN and NbN. The hardest coatings, HV ∼ 51.5 Pa, deposited with magnetic plasma guiding had a single-phase cubic δ-(Ti,Nb)N structure and a Ti:Nb ratio of ∼ 50:50 (at.%).Multilayer coatings TiN/NbN consisting of 20-40 alternating TiN and NbN layers with total thickness of 4-5 μm increased the life time of cemented carbide cutting inserts at turning tough Ni-base alloys by 2-7 times relative to uncoated cutting tools, while conventional vacuum arc deposited TiN coatings were not effective in machining of these alloys.     

VN基硬质耐磨涂层的制备及其性能

目的在N2及其与C2H2混合气氛下,制备VN基硬质耐磨涂层,研究VN基涂层的结构及力学、耐磨、抗腐蚀性能,为工业化应用积累科学数据。方法采用阳极层离子源辅助阴极电弧离子镀系统,在高速钢衬底上制备VN、VCN和VCN/VN多层涂层,系统研究多层涂层调制周期厚度变化对涂层晶体结构、表面形貌、硬度、耐磨性及耐腐蚀性能的影响。结果 C原子的加入和VCN/VN多层涂层调制周期的变化对VCN/VN涂层的晶体结构、表面形貌、硬度、摩擦系数及耐腐蚀性能均有明显影响。随着VCN/VN涂层调制周期的增加,VN(200)衍射峰逐渐减弱并宽化,VN (111)衍射峰消失,涂层表面金属熔滴大颗粒数量减少,小颗粒数量明显增加。VN涂层硬度为1890HV,VCN涂层硬度为2290HV,VN/VCN多层涂层硬度为2350HV左右。对磨材料为氧化铝时,VN涂层的摩擦系数为0.74左右,VCN涂层和VCN/VN涂层的摩擦系数明显降低,在0.60左右,磨损机理由以磨削磨损为主(VN涂层)逐渐转化为粘着磨损为主(S5),磨削磨损起次要作用。随着C原子的加入和VCN/VN多层涂层调制周期的变化,涂层耐腐蚀性能明显增强,自腐蚀电位由VN的-0.26 V增大到VCN的-0.14 V,自腐蚀电流密度由1.63′10^-5 A/cm^2降低到2.7′10(-6) A/cm^2。结论采用阳极层离子源辅助电弧离子镀技术可制备VN基硬质耐磨涂层,C元素的加入可有效提高VN涂层的硬度,降低VN涂层的摩擦系数,增强VN涂层的耐腐蚀性能。VCN/VN多层涂层通过周期厚度的调制可以有效提高VN基涂层的硬度、耐磨及耐腐蚀性能。     

Ion beam assisted deposition and characterization of Zr-based multilayered coatings

ZrN/W multilayered coatings with different nanoscale modulation periods have been synthesized at different deposition time using ion beam assisted deposition. XRD, AES, Nanoindenter and profiler were employed to investigate the influence of modulation period on microstructure and mechanical properties of the coatings. The results showed that all superlattice coatings almost revealed higher mechanical property than the monolithic ZrN and W coatings. At modulation period of 8.6 nm, XRD pattern showed a significant mixture of strong ZrN (111), W (110), as well as weak ZrN (220) textures. It possessed the highest hardness (∼ 26 GPa), elastic modulus (∼ 310 GPa), and fracture resistance (∼ 80 mN), compared with the ones with other modulation period.     

多弧离子镀制备CrAlSiN/TiAlSiN纳米涂层的结构和性能研究

目的研究调制周期对CrAlSiN/TiAlSiN纳米复合涂层结构和力学性能的影响。方法采用多弧离子镀技术,以AlCrSi靶和AlTiSi靶作阴极弧靶材料,通过改变衬底的转速(转速分别为2、4、6、8r/min)来调整涂层结构的周期,制备不同调制周期CrAlSiN/TiAlSiN纳米复合涂层。用X射线衍射仪、X射线光电子能谱仪、扫描电子显微镜和原子力显微镜,测量了涂层的组织结构、化学成分、表面及截面形貌,用显微硬度计、划痕试验仪和摩擦仪测量了不同调制周期的涂层的力学性能。结果不同转速下,CrAlSiN/TiAlSiN纳米复合涂层具有相同的晶相结构,包含CrAl、CrN和TiN,其中Al元素几乎全部固溶在CrAl相中。Si元素在涂层中以非晶相的形式存在或被非晶化合物所包裹。随着转速的增大,复合涂层的硬度呈现先增大后减小的趋势,而摩擦因数与均方根粗糙度则呈现出先减小后增大的趋势,即硬度越大,摩擦因数和均方根粗糙度越小。结论CrAlSiN/TiAlSiN纳米复合涂层的硬度和摩擦因数受调制周期的影响较大。当转速为6r/min时,制备的涂层具有最大的显微硬度(38GPa)和最小的摩擦因数(0.375)。     

真空退火对TC4钛合金表面Ti/TiN多层复合涂层性能的影响

金属基体材料表面硬质膜层在服役过程中,残余应力在膜基界面以及膜层内部界面之间的积聚会导致膜层发生界面剥落失效。以TC4钛合金基体表面Ti/TiN多层复合膜层为研究对象,探讨真空退火对复合膜层结构及性能的影响,并表征退火前后复合膜层的界面划痕失效以及抗粒子冲蚀性能。结果表明,真空退火促进了膜层内部以及膜基界面两侧原子的热扩散,使得界面结构特征明显弱化。界面状态的改变使得复合膜层的表面显微硬度降低以及膜基结合强度提高。在划痕载荷作用下,复合膜层抵抗裂纹沿界面扩展的能力得到增强。真空退火有助于提高膜层的强韧性匹配,可有效抵抗小角度冲蚀粒子的犁削以及大角度粒子冲蚀下的疲劳,因此Ti/TiN多层复合膜层表现出较好的抗冲蚀性能。     

Microstructures and mechanical properties evaluation of TiAlN/CrSiN multilayered thin films with different bilayer periods

The Ti_0.45Al_0.55N/Cr_0.75Si_0.25N nanoscale multilayered coatings were deposited periodically by a bipolar asymmetric pulsed DC reactive magnetron sputtering technique. The structures and bilayer period of multilayer coatings were characterized by an X-ray diffractometer. The surface and cross-sectional morphologies of thin films were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The surface roughness of thin films was explored by atomic force microscopy (AFM). A nanoindenter, a micro Vickers hardness tester and pin-on-disk wear tests were used to evaluate the hardness, fracture toughness and tribological properties of the thin films, respectively. Six coatings with bilayer period ranges from 6 nm to 40 nm were produced in this work. It was observed that the hardness increased with increasing bilayer period and reached the maximum at 12 nm and then leveled off at periods larger than 12 nm. An optimal hardness, and plastic deformation resistance, as well as adequate tribological behaviors were found on the coating with a critical bilayer period of 12 nm.