Structure and mechanical properties of Cr–B–N films deposited by reactive magnetron sputtering

Cr–B–N films with various B contents were deposited by reactive magnetron sputtering from the co-deposition of Cr and B targets in the presence of the reactive gas mixture. Comparative studies on microstructure and mechanical properties between CrN and Cr–B–N films with various B contents were conducted. The addition of B to CrN films caused a decrease of the crystallization of the films, while the B existed mainly as amorphous phase of BN compound in the CrBN films. The mechanical properties were also improved. And the Cr–B–N films with 6.1 at.% B content showed highest hardness and lowest wear rate.     

Microstructure and mechanical properties of W-C:H coatings deposited by pulsed reactive magnetron sputtering

Reported are results of microstructure, mechanical and tribological properties studies for thin, amorphous hydrogenated carbon based coatings with tungsten content from 4.7 at.% up to 10.3 at.%. Studied coatings have been deposited by pulsed, reactive magnetron sputtering on substrates under planetary rotation. Resulting coatings, characterized by transmission electron microscopy (TEM) also at high resolution (HREM), show multilayer structure consisting of sub-layers of W-C:H type, with alternately high and low tungsten concentration. Thickness and number of sub-layers depend on rotation speed of planetary substrate holder. An average tungsten concentration decreases with increasing partial pressure of reactive gas (C₂H₂) during deposition. More insight into the microstructure of coatings provided HREM analysis showing crystalline precipitations of about 1-2 nm in size as well as tungsten-rich and tungsten-poor W-C:H sub-layers. Raman spectra confirm presence of amorphous, hydrogenated carbon (a-C:H) phase in the coatings. Microhardness of studied coatings depends on tungsten content and increases from 10.7 GPa to 13.7 GPa, for 5.1 at.% and 10.3 at.% of tungsten content, respectively. The highest cracking resistance and best adhesion (L_c2 = 78 N and HF1) has been achieved for coatings containing 4.9 at.% of tungsten and a sub-layer thickness of 5 nm. Tribological processes occurring in the coating-coating contact zone are dominated by graphitization and oxidation of W-C:H coating. Very low friction coefficient (0.04) and low wear rate seems to be an effect gaseous micro-bearing by tribo-generated carbon oxides and methane as well as hydrogen released from the coating. In the W-C:H-steel contact zone a tribo-layer composed of iron and tungsten oxides mixed with graphite-like products is growing at the surface of steel counterpart. This tribo-layer becomes a barrier restricting direct contact of steel with the coating and thus preventing it from further intense wear.     

Phase equilibria and thermal analysis of Si–C–N ceramics

The phase reactions, crystallization behaviour and thermal degradation of two Si–C–N ceramics derived from precursors VT50 and NCP200, respectively, were studied by means of CALPHAD type thermodynamic calculations and experimental investigations by DTA/TG, XRD and SEM/EDX. The phase reaction Si₃N₄+3C=3SiC+2N₂ proceeds during the thermal degradation of both ceramics. Additionally, the phase reaction Si₃N₄=3Si+2N₂ occurs during the thermal degradation of the NCP200 ceramic. To explain quantitatively the high temperature behaviour of Si–C–N ceramics, thermodynamic functions, the reaction scheme, isothermal sections, isopleths, phase fraction diagrams and phase composition diagrams (for gas partial pressures) were calculated. The computer simulations were confirmed by the experiments for both ceramics.     

反应磁控溅射沉积工艺对Cr-N涂层微观结构的影响

研究在不同工艺条件下用直流反应磁控溅射技术在T10衬底上制备Cr-N涂层,并采用光电子能谱仪和XRD依次分析Cr-N涂层的表面结构和工艺参数对Cr-N涂层成分及相组成的影响。结果表明,Cr-N涂层在存放一段时间后表面产生复杂的Cr2O3相以及Cr（O2 N）x相;常温下随着N2含量的增加,涂层相结构逐渐由Cr转变为化学比的CrN相。当N2含量为33-3％时,Cr-N涂层的相成分主要为Cr2N＋CrN。并发现衬底偏压直接影响Cr-N系涂层的晶态及取向特征,当偏压增加到-130V时,Cr-N涂层中β-Cr2N相结构逐渐转变为（110）和（300）取向结构。     

Microstructure and properties of low friction TiC---C nanocomposite coatings deposited by magnetron sputtering

The objective of nanocomposite coatings combining hard and lubricant phases is the development of advanced multi-functional protective thin films showing abrasion resistance, and simultaneously, low friction. Up to now, no clear relation between constitution, microstructural properties and performance of such nanocomposite coatings based on dry lubricants like carbon or MoS₂ has been evaluated. Deposition techniques, constitution, properties and performance of magnetron-sputtered nanocomposite coatings in the TiC---C system are presented. The Vickers hardness could be optimized to values of polycrystalline TiC thin films, and at the same time, low friction coefficients against steel, similar to diamond-like amorphous carbon, could be realized. The mechanical properties and the tribological behavior of these thin films are related to the chemical composition and the microstructure of these advanced materials, characterized by electron microprobe analysis, Auger electron spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and high resolution transmission electron microscopy.     

Si_3N_4/CrN nanostructured multilayers grown by RF reactive magnetron sputtering

1　INTRODUCTIONInrecentyears ,ceramicsuperhardnesscomposi tionally modulatedmultilayerfilmshavebeenactivelyinvestigated[18] .Theresearchresultsshowthatmul tilayerscancombinethepropertiesoftheconstituentmaterialsandhavemoreexcellent propertiesthanthoseofthesingle layerfilm .Alargenumberofin ternalinterfaceswhichare paralleltothesubstratesurfacecanretardcrackpropagationandprovidebar rierstodislocationmovement.Multilayerswithopti mizedinterfaceareasseemtobemostpromisingwithrespecttoanoptimum…     

等离子体增强磁控溅射制备Ti(Cr)SiC(O)N涂层的结构和机械性能研究

采用等离子体增强磁控溅射(PEMS)方法分别在硬质合金和硅片上制备了TiSiCN, TiSiCON, TiCrSiCN, TiCrSiCON, CrSiCN 和 CrSiCON涂层。采用XRD、SEM、EDS、显微硬度计及销盘式摩擦磨损试验机对含氧涂层和不含氧涂层的微观结构、成分和机械性能进行了研究。研究结果表明,TiSiCON, TiCrSiCON和 CrSiCON含氧涂层为TiN型（或CrN型）面心立方(fcc)结构,但是TiSiCON, TiCrSiCON, 和 CrSiCON涂层中氧的存在会导致产生疏松的结构以及相比于不含氧涂层TiSiCN, TiCrSiCN和CrSiCN更多的缺陷;氧的加入会导致Ti(Cr)SiCN涂层硬度和弹性的下降;TiCrSiCON和 CrSiCON两种含氧涂层相比于不含氧涂层TiCrSiCN和CrSiCN有更低的摩擦系数和磨损率;然而,TiSiCON相比于TiSiCN却表现出更高的摩擦系数和磨损率。     

磁控溅射法制备的羟基磷灰石—氧化锆涂层的力学性能(英文)

采用磁控溅射法在Ti6Al4V钛合金基体上制备羟基磷灰石(HA)-氧化锆(ZrO2)复合涂层,通过SEM、EDS、XRD和划痕法对50HA-50ZrO2和75HA-25ZrO2(质量分数,%)涂层进行表征,分析HA含量对涂层残余应力的影响。实验结果表明,HA-ZrO2复合涂层的物相为HA、ZrO2和Y2O3,在复合过程中HA部分发生分解,产生TCP和CaO等杂质相;涂层表面呈多孔状,有利于类骨组织的生长,50HA-50ZrO2和75HA-25ZrO2深层的表面粗糙度分别为1.61μm和2.92μm;涂层结合界面为机械结合方式,划痕法测量的50HA-50ZrO2和75HA-25ZrO2深层界面结合强度分别为30N和17.5N,随着HA含量的增加,涂层结合强度呈现下降的趋势;50HA-50ZrO2和75HA-25ZrO2涂层的残余应力分别为(-399.1±3)MPa和(-343.2±20.3)MPa,适当增加HA可以减小涂层的残余应力。     

反应磁控溅射制备Ti-Si-N薄膜的摩擦磨损性能

用反应磁控溅射方法,在不锈钢表面沉积Ti-Si-N薄膜.用原子力显微镜观察薄膜的表面形貌,Ti-Si-N颗粒尺寸小于0.1 μm,用亚微压入仪测试薄膜硬度,当硅的摩尔分数为9.6%时,薄膜硬度出现最大值47 GPa.球-盘式摩擦磨损结果表明,Ti-Si-N薄膜的耐磨性能明显优于TiN薄膜,加入少量硅元素后,TiN薄膜的抗磨损性能有显著提高,但Ti-Si-N薄膜的室温摩擦系数较高(0.6～0.8),高温下摩擦系数也仅轻微降低(550℃,0.5～0.6).由于Ti-Si-N薄膜的摩擦系数可能与磨损中氧化物生成量的增加有关,常温下Ti-Si-N薄膜的摩擦系数随硅摩尔分数的增加而增大,而高温下Ti-Si-N薄膜的摩擦系数随硅含量上升而降低.     

Microstructure and tribological properties of CrN and CrSiCN coatings

Three CrN based coatings were deposited on 17-4PH precipitation hardening stainless steel substrate using plasma enhanced magnetron sputtering (PEMS) technique. The three coatings evaluated in this study assumed the nominal compositions of Cr_0.68N_0.32 (sample CrN), Cr_0.55Si_0.013C_0.14N_0.3 (sample CrSiCN-1), and Cr_0.43Si_0.034C_0.25N_0.29 (Sample CrSiCN-2)_. The microstructure, mechanical properties and wear and erosion resistance of the coatings were evaluated to examine the effect of Si and C additions to CrN. The results indicated that with the incorporation of Si and C, the microstructure transformed from hexagonal Cr₂N (for CrN coating) to B1 structure containing crystalline Si₃N₄ (for CrSiCN-2). The initial addition of Si (1.3 at.%) and C resulted in increase of hardness (H), Young's modulus (E) and the ratio of H³/E². With further increase in Si (3.4 at.%) and C, the hardness and Young's modulus decreased. The coefficient of friction was observed to decrease with the addition of Si and C, irrespective of microstructure changes. The combination of reduced coefficient of friction and microstructure modifications has resulted in improved wear resistance for sample CrSiCN-2 (with a wear rate ∼ 60% lower than CrN). The erosion resistance test results showed brittle erosion characteristics for samples CrN and CrSiCN-1 where erosion rate increased with erodent impingement angle and reached the highest rate at 75° and 90°, respectively. CrSiCN-2 coating, while exhibiting higher erosion rate at low impingement angle, demonstrated reduced erosion rate at higher angle due to the ductile nature of the coating under erosion test condition.     

磁控溅射Ti1-xAlxN薄膜的微结构及性能研究

利用磁控反应溅射法制备了不同A1含量的Ti1-xAlxN薄膜.采用能谱仪、X射线衍射仪及纳米显微力学探针分析了薄膜的成分、微结构及薄膜的硬度,研究了Al含量对薄膜的微结构、硬度及高温抗氧化性能的影响.结果表明,薄膜为面心立方结构,呈(111)择优取向;薄膜的硬度及抗氧化性能均随着Al含量增加而提高.     

The effect of pulsed magnetron sputtering on the structure and mechanical properties of CrB2 coatings

CrB₂ thin films possess desirable combinations of properties (high hardness, wear resistance, chemical inertness, high thermal and electrical conductivity), which are attractive for a wide range of potential applications. Pulsed magnetron sputtering (PMS) of loosely-packed blended powder targets has allowed the deposition of stoichiometric chromium diboride coatings. The structure and properties of these coatings were found to be strongly dependent on the deposition process parameters; therefore investigation of the coating structures could explain certain differences between them and provide important information about the characteristics of the deposition process. In this study, characterization of the CrB₂ films was performed by scanning and transmission electron microscopy (SEM and TEM) techniques. The microstructures and properties of coatings deposited with different parameters are compared and changes that resulted from the variation of these parameters (particularly the pulsing duty cycle and the substrate biasing conditions) are discussed. The results show that besides the pulsing frequency, the target pulsing duty cycle is an important parameter of the PMS process, which is able to affect such coating properties as hardness, thickness and stress. Coating thickness measurement results suggest more intense bombardment of a growing film by energetic ions at lower values of duty cycle. Structural TEM analysis revealed two extremely different types of coating microstructures, obtained at quite similar substrate biasing conditions, i.e. floating (∼ − 15 V) and negatively biased (− 30 V). It appears that the structures of the coatings deposited at the negatively biased substrate are significantly affected by high-energy ion bombardment, which is a peculiarity of PMS that can modify film growth conditions. These conditions are not present when the substrate is allowed to float.     

磁控溅射制备TiCN复合膜的微结构与性能

通过磁控溅射技术制备一系列不同石墨靶功率的TiCN复合膜。分别利用X射线衍射仪、纳米压痕仪和高温摩擦磨损仪研究薄膜的微观结构、力学性能及室温和高温摩擦磨损性能。结果表明:随着石墨靶功率的增加,TiCN(111)峰逐渐宽化,晶粒尺寸逐渐减小,薄膜最后接近非晶结构。薄膜的硬度与弹性模量呈先增大后减小的趋势,在石墨靶功率为90 W时薄膜的硬度和弹性模量最大,分别为28.2和230 GPa。随着石墨靶功率的增加,室温下TiCN复合膜的摩擦因数逐渐减小,TiCN复合膜的耐磨性能明显提高。当环境温度升高到300~500℃时,TiCN薄膜的摩擦因数明显增大。TiCN复合膜的摩擦磨损性能受薄膜微观结构、空气中的水蒸气和氧气及环境温度等一系列因素的影响。     

深振荡磁控溅射复合沉积CrN/TiN超晶格涂层的摩擦学性能

研究了IN718高温合金、WC-6%Co硬质合金和Si(100)基体上深振荡磁控溅射复合沉积CrN/TiN超晶格涂层的摩擦学性能。研究表明,涂层的生长对基体的类型没有选择性。随着基体硬度的升高,划痕结合力失效临界载荷增大,涂层结合力失效机制由翘曲失效转变为基体/涂层协同变形,未发现涂层的剥落失效。载荷为2N时,磨损机制由磨粒磨损和氧化磨损转变为轻微磨粒磨损。载荷为4 N时,IN 718基体上涂层的磨损机制为严重的氧化磨损,WC-6%Co基体上的涂层的磨损机制为磨粒磨损和氧化磨损,氧化物的产生、堆积和转移导致摩擦系数的波动。     

反应磁控溅射(CrMoTaNbVTi)N多主元薄膜的微观组织与机械性能研究

本文采用直流反应磁控溅射方法,通过溅射（CrMoTaNbV）镶嵌靶和纯Ti靶制备了(CrMoTaNbVTi)N多主元氮化物薄膜。研究了不同氮气流量比RN对(CrMoTaNbVTi)N薄膜的微观结构、力学性能和摩擦学性能的影响。结果表明,当RN=0% 和10%时薄膜为简单的体心立方结构,当RN=20%、30% 和40%时为简单的面心立方结构。随着氮气流量比RN的增大,表面颗粒逐渐减小,断面柱状晶更为致密,同时(CrMoTaNbVTi)N薄膜的残余应力、膜基结合力、硬度和弹性模量逐渐增大,且当RN=40%时达到最大值,分别为-3.3 GPa, 352 mN, 25.6±1.2 GPa 和 278.8±11.2 GP。RN =40%制备的氮化物薄膜具有最小的比磨损率,相较合金薄膜降低了约1个数量级,表现出优异的耐磨损性能。     

Wear-resistant Ti–B–N nanocomposite coatings synthesized by reactive cathodic arc evaporation

Wear-resistant Ti–B–N coatings have been synthesized by reactive arc evaporation of Ti–TiB₂ compound cathodes in a commercial Oerlikon Balzers Rapid Coating System. Owing to the strong non-equilibrium conditions of the deposition method, a TiN–TiB_x phase mixture is observed at low N₂ partial pressures, as determined by elastic recoil detection analysis, X-ray diffraction, X-ray spectroscopy, transmission electron microscopy and selected area electron diffraction. The indicated formation of a metastable solid solution of B in face-centered cubic TiN gives rise to a maximum in hardness (>40 GPa) and wear resistance on the expense of increased compressive stresses. A further saturation of the nitrogen content results in the formation of a TiN–BN nanocomposite, where the BN phase fraction was tailored by the target composition (Ti/B ratio of 5/3 and 5/1). However, the amorphous nature of the BN phase does not support self-lubricious properties, showing friction coefficients of 0.7 ± 0.1 against alumina. The effect of an increased bias voltage on structure and morphology was investigated from −20 to −140 V and the thermal stability assessed in Ar and air by simultaneous thermal analysis up to 1400 °C.     

磁控溅射法制备SnS薄膜的结构和光学性能

利用磁控溅射法在FTO玻璃上制备了Sn S薄膜。采用X射线衍射仪、扫描电子显微镜和紫外可见分光光度计对不同溅射参数下制备的Sn S薄膜的晶体结构、表面形貌和光学性能进行研究,确定出制备Sn S薄膜的最优溅射参数。结果表明:溅射功率为28 W,沉积气压在2.5 Pa时,制备出的Sn S薄膜在(111)晶面具有最好的择优取向,薄膜微观形貌呈单片树叶状,晶粒粒径约370 nm,晶粒分布均匀,薄膜表面光滑致密;最优溅射参数下制备的Sn S薄膜的吸收系数可达到105cm-1,比其他方法制备的Sn S薄膜的吸收系数值高,禁带宽度为1.48 e V,与半导体太阳能电池所要求的最佳禁带宽度(1.5 e V)十分接近。     

The effect of thermal ageing on microstructure and mechanical properties of Al–Si–Fe/Mg alloys

In this paper the microstructure and ageing behavior of Al–Si–Fe/Mg alloys produced through sand-casting route is presented. 4.0–6.0 wt% Mg was added to Al–Si–Fe alloy. Standard mechanical properties test samples were prepared from the sand cast 25 mm diameter by 45 mm rods. Thermal ageing was done for 6 h at 200 °C. The ageing characteristics of these alloys were evaluated using tensile properties, hardness values, impact energy and microstructure as criteria. The thermal aged samples exhibited higher yield strength, tensile strength and hardness values as the weight percent of magnesium increased up to 5 wt% in the Al–Si–Fe/Mg alloys as compared to as-cast samples. The optimum values were obtained at 5 wt%Mg. Lower percent elongation, reduction in area and impact energy values were obtained for age-hardened Al–Si–Fe/Mg alloy samples as compared to as-cast samples. The increases in hardness values and strength during ageing are attributed to the formation of coherent and uniform precipitation in the metal lattice. It was found that the age-hardened showed acceleration in ageing compared to the as-cast alloy. However, the 5 wt%Mg addition to the alloy showed more acceleration to thermal ageing treatment. These results show that better mechanical properties are achievable by subjecting the as-cast Al–Si–Fe/Mg alloys to thermal ageing treatment.     

Microstructure and tribological properties of Cuss-toughened Cr–Cu–Si metal silicide alloys

Wear resistant Cr–Cu–Si metal silicide alloys with different Cu contents were fabricated by the laser melting process. The Cr–Cu–Si alloys have a similar microstructure consisting of the Cr₅Si₃/CrSi dual-phase primary dendrites and the interdendritic Cu-based solid solution (Cu_ss). The Cu content has no effect on the phase constitutions of the alloys. The Cr₅Si₃/CrSi dendrite volume fraction and hardness of the Cr–Cu–Si alloys decrease with the increasing Cu content. Wear test results indicate that all the Cu_ss-toughened metal silicide alloys have excellent wear resistance and low coefficient of friction. Wear resistance increases and friction coefficient decreases with the decreasing Cu content.     

Microstructure and tribological properties of diamond-like carbon and TiAlSiCN nanocomposite coatings

Diamond-like carbon (DLC) and TiAlSiCN nanocomposite coatings were synthesized by multi-plasma immersion ion implantation and deposition. The DLC content in the composite coating was controlled by the flow ratio of N₂ to C₂H₂ during the deposition process. The microstructure and tribological properties of the as-deposited coatings were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation and ball-on-disk friction tests. The TEM results show that all the DLC-TiAlSiCN coatings had a two phase composite structure of the TiCN nanocrystals embedded in an amorphous matrix consisting of a-Si₃N₄, a-SiC, a-CN and DLC. TEM observations also reveal that the spacing between the adjacent nanocrystals increases with DLC content. In addition, the DLC-TiAlSiCN nanocomposite coating with a small crystalline spacing of about 0.6 nm shows a higher hardness up to 50 GPa and a larger friction coefficient. An increase in the DLC content of the coating benefits its friction coefficient while its hardness decreases. The friction coefficient reduces to 0.14 when the DLC content is about 31%.