两种常用碳化硅反射镜基底表面改性的研究

利用霍尔离子源辅助电子束蒸发方法,分别在反应烧结碳化硅(RB-SiC)和常压烧结碳化硅(Sintered SiC,S-SiC)基底材料上制备了Si改性膜层,并进行了相关性能测试和分析。经过表面改性,两种基底的表面粗糙度(rms)大幅地降低,镀银后的反射率有较大地提高,基底表面光学质量已满足工程应用要求。在相同工艺条件下,S-SiC基底改性后效果好于RB-SiC基底的情况,主要是因为Si膜在两种基底表面生长情况不同所致。     

空间用SiC反射镜表面改性的性能和可靠性评估

根据空间应用项目需求,采用等离子辅助电子束蒸发方法对RB-SiC基底进行了表面改性,并对表面改性的性能和可靠性进行了相关评估.经测试,改性后RB-SiC基底表面粗糙度(rms)降低到0.632 nm;散射系数降低到2.81%,500～1 000 nm范围的平均反射率提高到97.05%,已经接近于抛光良好的微晶玻璃的水平;改性涂层温度稳定性高,与基底结合牢固;加工后,面形精度达到0.119λ(PV)和0.014λ(rms),λ=632.8 nm.评估结果表明,这种SiC基底表面改性的工艺是可靠的,其光学性能满足空间高质量光学系统的要求,适宜空间环境应用.     

基于磁控溅射和ICP刻蚀的RB-SiC表面平坦化工艺

采用射频磁控溅射技术在RB-SiC表面沉积Si平坦化层,通过正交试验研究了射频功率、Ar流量和工作气压三个因素对薄膜表面质量和形貌的影响规律,以获取最佳的薄膜沉积参数.射频功率120 W、工作气压1.2Pa和Ar流量40sccm条件下获得了最佳质量的平坦化样品,利用电感耦合等离子体对平坦化膜层进行刻蚀抛光,通过Lambda950分光光度计测试不同工艺阶段样品表面的反射率.结果表明,相比于未处理的RB-SiC初始样品,经过平坦化和等离子体刻蚀的样品表面粗糙度标准差值由1.819nm减小至0.919nm,样品表面反射率相应地提高了2%.由此说明射频磁控溅射平坦化沉积与电感耦合等离子体刻蚀的组合工艺可实现RB-SiC表面的高质量加工.     

空间反射镜基底材料碳化硅表面改性研究

直接抛光后的SiC反射镜表面光学散射仍较大,无法满足高质量空间光学系统的心用需求.为此必须对SiC反射镜进行表而改性,以获得高质量的光学表面.目前国际上较为流行的足制备Si或SiC改性层进行表面改性.分别采用离子辅助电子束蒸发方法制备Si和SiC改性层进行改性,相关测试结果表明:Si改性层结构为立方相,改性后基底表面粗糙度(rms)降到0.620 nm,散射系数减小到1.52%;SiC改性层结构为非晶相,改性后基底表面粗糙度(rms)降到0.743 nm,散射系数减小到2.79%.两种改性层均与基底结合牢固,温度稳定性较高.从可靠性方面考虑,目前在国内第一种方法更适于实际工程应用.该工艺改性后SiC基底表面散射损耗大大降低,表面质量得到明显改善.镀Ag后表面反射率接近于抛光良好的微晶玻璃的水平,已能够满足高质量空间光学系统的应用需要.     

在有机玻璃上射频溅射ITO组合薄膜

利用射频磁控溅射技术在有机玻璃表面上一次完成表面活化、ITO膜制备、SiO2 减反射膜制备过程。利用低能等离子体对有机玻璃表面进行改性以提高ITO膜的附着力。研究了氧分压等工艺参数对ITO膜导电性能及光学性能的影响。     

磁控溅射制备微球表面金属Mo涂层的研究

利用磁控溅射制备了各种工艺参数不同的微球表面金属Mo涂层样品,并通过白光干涉仪和扫描电子显微镜对样品的表面及剖面进行了系统的测试分析。分别探究了溅射工作气压和沉积制备时间对微球表面Mo涂层表面形貌以及结晶质量的影响规律。结果表明通过优化工艺参数可制备微球直径约为800μm、涂层厚度为3.5μm到14.1μm、厚度均匀性良好的微球表面Mo涂层。Mo涂层中的晶粒呈现出柱状结构致密堆积在一起,且随涂层的厚度增加晶粒间空隙增大。     

点火黑腔用铝铜复合芯轴的制备及性能

选取纯度较高的1100铝棒作为加工模芯的原材料,利用金刚石车床精加工出表面粗糙度均方根值小于20 nm的铝模芯,采用磁控溅射的方法在铝模芯上制备厚度大于5 m的铜防护层,得到铝铜复合芯轴。对制备的铜防护层的表面微观结构、结晶性能、厚度一致性进行了分析测试,结果表明磁控溅射法制备的铜防护层沿(111)面择优生长,表面粗糙度均方根值小于30 nm,厚度一致性优于95%,圆柱度小于1 m。镀层与基底结合力强,可满足大厚度黑腔涂层的制备需求。     

磁控溅射制备的W,WSi2,Si单层膜和W/Si,WSi2/Si多层膜应力

采用直流磁控溅射技术制备了厚度约100 nm的W,WSi2,Si单层膜和周期约为20 nm,Si膜层厚度与周期的比值为0.5的W/Si,WSi2/Si周期多层膜.利用台阶仪对镀膜前后基底表面的面形进行了测试,计算并比较了不同膜系的应力值.结果表明:W单层膜表现出较大的压应力,而W/Si周期膜则表现为张应力.WSi2单层...     

氮化铬过渡层对四面体非晶碳薄膜在高速钢基底上附着特性影响的研究

利用磁过滤阴极电弧与磁控溅射相结合的薄膜沉积技术在高速钢基底上 制备了氮化铬/四面体非晶碳(CrN/ta-C)复合涂层, 通过改变过渡层氮化铬(CrN)的制备工艺, 研究了四面体非晶碳(ta-C)薄膜在钢基底材料上的附着特性的变化. 结果表明, 随着氮气流量的增大, CrN/ta-C复合涂层中的氮化铬经过了Cr-Cr₂N-CrN的相变过程. 同时涂层的附着力也随着氮气流量的增大而增加, 但是当氮气流量超过30 sccm时, 涂层附着力会有所下降; 通过改变基片偏压, 复合涂层中氮化铬的择优取向与晶粒结构发生改变, 随着偏压的增大, 涂层附着力也会大大改善, 但是当偏压超过200 V, 涂层附着特性会略微降低. 通过涂层耐磨性的测试也表明, 在高速钢基底上, CrN涂层能显著提高ta-C薄膜在高速钢基底上的附着力, 同时显著提高耐磨特性. 关键词： 附着力 四面体非晶碳薄膜 X射线衍射 拉曼光谱     

大尺寸高性能X射线双通道多层膜反射镜研制

为满足同步辐射装置中X射线单色器的需求,在直线式磁控溅射设备上制备了W/Si和Ru/C双通道多层膜反射镜。制备的W/Si多层膜和Ru/C多层膜的周期厚度均为3 nm,平均界面宽度分别为0.30 nm和0.32 nm。在320 mm长度范围和20 mm宽度范围内,W/Si多层膜膜厚误差的均方根值分别为0.30%和0.19%,Ru/C多层膜膜厚误差的均方根值分别为0.39%和0.20%。对制备的样品进行了表面形貌测试和非镜面散射测试,对比了W/Si多层膜和Ru/C多层膜的表面和界面粗糙度大小。硬X射线反射率测试结果表明,W/Si多层膜和Ru/C多层膜在8.04 keV能量点处的一级布拉格峰测试反射率分别为63%和62%,角分辨率均为2.6%。基于以上研究,在尺寸为350 mm×60 mm的高精度Si平面镜表面镀制了W/Si和Ru/C双通道多层膜,并且其被成功应用于上海同步辐射光源线站中。     

The structure and tribological behaviors of CrN and Cr-Ti-N coatings

The Cr-Ti-N coatings with different composition were deposited in a medium frequency magnetron sputtering system on Si (1 1 1) substrates. The structures, surface morphology and wear properties were measured. The binary CrN coatings, formed a single-phase fcc structure with nearly random (1 1 1), (2 0 0) and (2 2 0) orientation, while for the Ti was introduced, coatings show a preferred orientation of (2 0 0). Cr-Ti-N coating shows a much smoother surface than CrN coating. Cr-Ti-N coating with 31.75% Ti content shows the best wear behavior. The excellent tribological properties of this composition coating are corresponding to the solid solution nitride structures.     

Synthesis of Ti-Si-N nanocomposite coatings by a novel cathodic arc assisted middle-frequency magnetron sputtering

Ti-Si-N nanocomposite coatings were synthesized by using a cathodic arc assisted middle-frequency magnetron sputtering system in an industrial scale. X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy were employed to investigate the chemical bonding and microstructure of the coatings. Atomic force microscope and scanning electron microscope were used to characterize the surface and cross-sectional morphologies of the samples. The coating was found to be nc-TiN/a-Si₃N₄ structure and exhibit a high hardness of 40 GPa when the Si content was 6.3 at.%.     

Study of physicochemical and biological properties of calcium phosphate coatings prepared by RF magnetron sputtering of silicon-substituted hydroxyapatite

Coatings based on pure silicon and silicon-substituted hydroxyapatite were grown by RF magnetron sputtering. The coating surface morphology, phase and elemental composition were studied by scanning electron microscopy, energy-dispersive X-ray analysis, and infrared spectroscopy. It was found that coatings are X-ray-amorphous, their elemental composition being controlled by the sputtered target composition. The distribution of elements over the coating surface is homogeneous. Medical and biological properties of coatings were studied in vivo and in vitro. Osteogenic properties of coatings were studied. Coatings grown by sputtering of a stoichiometric hydroxyapatite target are biocompatible without osteoinductive activity. The introduction of silicate ions into the hydroxyapatite structure that forms an electrode target significantly enhances the in vivo effect of CaP magnetron coatings on the osteogenic activity and stromal bone-marrow stem cells.     

(Ti,Al,Si,C)N nanocomposite coatings synthesized by plasma-enhanced magnetron sputtering

Materials’ surface service property could be enhanced by transition metal nitride hard coatings due to their high hardness, wear and high temperature oxidation resistance, but the higher friction coefficient (0.4-0.9) of which aroused terrible abrasion. In this work, quinternary (Ti,Al,Si,C)N hard coating 3-4 μm was synthesized at 300 °C using plasma enhanced magnetron sputtering system. It was found that the coating's columnar crystals structure was restrained obviously with the increase of C content and a non-columnar crystals growth mode was indicated at the C content of 33.5 at.%. Both the XRD and TEM showed that the (Ti,Al,Si,C)N hard coatings had unique nanocomposite structures composed of nanocrystalline and amorphous nc-(Ti,Al)(C,N)/nc-AlN/a-Si₃N₄/a-Si/a-C. However, the coatings were still super hard with the highest hardness of 41 GPa in spite of the carbon incorporation. That a-C could facilitate the graphitization process during the friction process which could improve the coating's tribological performance. Therefore, that nanocomposite (Ti,Al,Si,C)N coatings with higher hardness (>36 GPa) and a lower friction coefficient (<0.2) could be synthesized and enhance the tribological performance and surface properties profoundly.     

Sputtering pressure effects on the structural and mechanical properties of TiVCr alloy coatings

In this study, TiVCr alloy coatings were deposited on Si substrates by magnetron sputtering system at different working pressures (0.33-1 Pa). The TiVCr coatings have a composite structure with amorphous and body-centered cubic (bcc) crystal phases comprised of bundles of fine fibrous structures and V-shaped columnar structures, respectively. Compared with the amorphous zone, the crystalline zone has a denser and more compact structure. The coating microstructure became more porous as working pressure increased. Consequently, the crystal zones of the deposited coatings at 0.33 Pa obtained higher hardness (11.6 GPa) while the deposited coatings at 1 Pa achieved lower hardness (4.5 GPa).     

极紫外多层膜技术研究进展

在极紫外波段,任何材料都表现出极强的吸收特性,因此,采用多层膜实现高反射率是构建正入射式光学系统的唯一途径。本文总结了极紫外多层膜的发展进程,叙述了制备极紫外多层膜的关键技术(磁控溅射、电子束蒸发、离子束溅射)以及它们涉及的相关设备。由于多层膜反射式光学元件主要应用于极紫外光刻与极紫外天文观测,文中重点讨论了极紫外光刻系统对多层膜性能的要求,镀膜过程中的面形精度和热稳定性等问题;同时介绍了极紫外天文观测中使用的多层膜的特点,特别讨论了多层膜光栅的制备技术和亟待解决的问题。     

Study on the laser treatment of electroless Ni-P-SiC composite coatings

Effect of the laser treatment on electroless Ni-P-SiC composite coatings was investigated. The microscopic structure, surface morphology, ingredient, and performance of the Ni-P-SiC composite coatings were synthetically analyzed by the use of X-ray diffraction apparatus, scanning electron microscope, energy distribution spectrometer, micro-hardness tester, wear tester and so on. It was found that the composite coatings did make crystalloblastic transformation after laser heating. Structural analysis confirmed that some new types of phase Ni2Si or Ni3Si compound would emerge in the Ni-P-SiC coatings after laser treatment. The micro-hardness measurement results showed that when the laser power was 450 W with scanning speed of 0.5 m/min, the hardness of the coating was superior to the coating obtained by the conventional furnace heating, and wear resistance of the composite coating after laser treating could also improve.     

The mechanism of PEO process on Al–Si alloys with the bulk primary silicon

This study focuses on mechanism of ceramic coating on Al–Si alloys with bulk primary Si using plasma electrolytic oxidation (PEO) technology. Al–Si alloys with 27–32%Si in weight were used as substrates. The morphologies, composition and microstructure of PEO coatings were investigated by scanning electron microscopy (SEM) with energy dispersive X-ray system (EDX). Results showed that the PEO process had four different stages. The effect of bulk Si is greatly on the morphology and composition of coatings at first three stages. Anodic oxide films formed on Al and Si phases, respectively. When the voltage exceeded 40 V, glow appeared and concentrated on the localized zone of interface of Al and Si phase. Al–Si–O compounds formed and covered on the dendrite Si phase surface, and the coating on bulk Si, which was silicon oxide, was rougher than that on other phase. If the treatment time was long enough, the coatings with uniform surface morphologies and elements distribution will be obtained but the microstructure of inner layer is looser due to the bulk Si.