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1.
《Journal of Adhesion Science and Technology》2013,27(1):245-253
Ar ion beam etching (IBE) can be used to roughen a Cu surface and thus improve the adhesion of subsequently spin-coated polyimide (PI) films. During Ar IBE, the surface morphology of sputter-deposited Cu changes from round bumps to a rough cone structure. The ultimate tensile strength (UTS) of the PI/Cu interface is increased for certain specific beam conditions. Under optimal conditions, the UTS of the etched PI/Cu interface (6.2 MPa) is twice that of the unetched PI/Cu interface (3.1 MPa). Cu is detected in the deposited PI by Rutherford backscattering spectrometry (RBS). The amount of Cu at the top surface of the 2.5 μm thick PI film is 0.1 at. %; this is determined by RBS and XPS. While the Cu is dissolved by polyamic acid and diffuses into the PI, an oxygen-rich region is formed in the Cu. The oxygen-rich region in Cu grows from 50 A (approximately Cu2O) before PI deposition to more than 2000 A (where the oxygen concentration is about 5 at. %) after PI deposition. The oxygen source is not the PI itself but either dissociated oxygen from the water vapor in the PI imidization process or a product of the chemical reaction between Cu and polyamic acid. 相似文献
2.
The main objective of the present research is to investigate the production of Cu-Al2O3 nanocomposite coating on a copper substrate using solution combustion synthesis. Solution combustion synthesis is mainly used to produce nanocomposite powders; however, in this study it is applied to produce nanocomposite coat. For this purpose, both copper and aluminum nitrates (Cu (NO3)2·3H2O and Al (NO3)3·9H2O) are used as oxidizers. Also, urea and graphite are respectively used as fuel to synthesize the Cu-Al2O3 nanocomposite and as inhibitor to prevent the oxidation of the synthesized copper. The microstructure and morphology of the nanocomposite coating, which includes 25 wt% alumina as the reinforcing phase, was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy at different fuel/oxidizer ratios ranging from 0.9 to 2. The temperature variation during the process was measured as a function of time using a precise thermocouple. Finally, micro-hardness and wear tests were conducted on the nanocomposite coating. The results verified the formation of Cu-Al2O3 nanocomposite coating. Time-temperature curve illustrated that the highest temperature was achieved at the fuel/oxidizer ratio of 1.25. The results of the microhardness and wear resistance test showed that these properties depend heavily on the fuel/oxidizer ratio, with the best condition attained at the ratio of 1.25. 相似文献
3.
《Diamond and Related Materials》1999,8(8-9):1549-1554
Adherent diamond coatings on steel and copper were obtained by using a titanium interlayer. The adhesion of the coatings was evaluated by scratch tests and micro-indentation tests. The diamond coating on steel exhibited a much higher critical load than on copper, as revealed by the scratch tests. However, an observation on the back of the scratch-delaminated film and on the corresponding substrate surface showed that the detachment occurred between the diamond film and the titanium interlayer. Therefore, the difference in the critical scratch load is due mainly to a substrate effect, making it difficult to compare the adhesion of different coatings.On the other hand, Knoop indentation tests showed interesting results: a small indentation load causes round spallation in the film with no observable crack. An exponential sink-in deformation under the indentation is proposed, y=−a exp(−bx). The coating adhesion is considered to be equivalent to the deformation stress at the edge of the spallation zone. The adhesion of diamond coatings on steel and copper with a titanium interlayer is evaluated quantitatively using this model. Furthermore, a thermal quench method is proposed to estimate the coating adhesion. The results found are in agreement with the indentation model. 相似文献
4.
《Diamond and Related Materials》2004,13(3):465-472
Fused silica substrates were pretreated by the ultrasonic vibration in the diamond powder slurry (UVDS). The influence of UVDS parameters such as the grain size of diamond powder, the liquid medium used to form the slurry, the weight ratio of diamond powder to liquid medium and the pretreatment time on the diamond nucleation density (DND) were systemically investigated. The grain size of diamond powder greatly affected the DND, the larger the grain size the higher the DND in our experiment conditions. The DND was about the same using acetone or ethanol or hexane medium. The best weight ratio of diamond powder (grain size 20–40 μm) to liquid medium was ∼1/60. Under appropriate pretreatment and CVD conditions, the DND of ∼1010 cm−2 was obtained on fused silica substrates. Continuous ultra-thin diamond films with uniform and smooth surface (diamond grain size: ∼150 nm and surface roughness: ∼6 nm) were synthesized in an improved hot filament chemical vapor deposition (HFCVD) system. Nano-damaged sites on the pretreated surface mainly enhanced the DND and shortened the incubation time of nucleation. 相似文献
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《Diamond and Related Materials》1999,8(2-5):202-206
Experimentally, it was shown that using a gas-dynamic correction in the plasma torch operation mode of jet expansion absence increases the efficiency of DC synthesis more than 10 times. Moreover, the diameter of the homogeneous part of a coating is increased not less than twice in relation to the diameter of the plasma jet.The theoretical explanation of the obtained result is given. It was shown that at subsonic speed of plasma flow spreading along the substrate radius, this effect can only be obtained at Reynolds numbers not exceeding the critical value Rr≤Rr cr=13456.The maximum area of uniform thickness DC is not less than 6 cm2. 相似文献
7.
Surface modification of high‐density polyethylene (HDPE) surfaces by plasma polymerization of glycidyl methacrylate (GMA) (the pp‐GMA‐HDPE surfaces), in the absence and presence of Ar plasma pre‐activation of the HDPE substrates, was carried out to enhance the adhesion of the polymer with evaporated copper. THe FTIR and X‐ray photoelectron spectroscopy (XPS) results suggested that the epoxide functional groups on the pp‐GMA‐HDPE surfaces had been preserved to various extents, depending on the RF power used during plasma polymerization. Ar plasma pre‐activation of the HDPE surface led to the strong interaction of the pp‐GMA layer with the HDPE substrate. GMA plasma polymerization at low RF powers and in the presence of Ar plasma pre‐activation was shown to be an effective method for enhancing the adhesion of HDPE with the evaporated Cu. An optimum adhesion strength of about 16 N/cm was achieved between the evaporated Cu and the pp‐GMA‐HDPE surface prepared by plasma polymerization of GMA at 5 W, 100 Pa, 20 sccm for 5 s on the HDPE surface pre‐activated by Ar plasma at 35 W, 100 Pa 20 sccm for 20 s. The adhesion enhancement of the Cu/pp‐GMA‐HDPE assemblies in the presence of Ar plasma pre‐activation of the HDPE substrate was attributed to the covalent bonding of the plasma‐polymerized GMA (pp‐GMA) layer with the HDPE surface, the preservation of the epoxide functional groups in the pp‐GMA layer, and the spatial interactions of pp‐GMA chains with the evaporated Cu matrix. 相似文献
8.
《Journal of Adhesion Science and Technology》2013,27(1):465-474
Polyimide (PI) films were modified by O2 reactive ion beam etching (RIBE) to enhance the adhesion of subsequently deposited copper films. The adhesion of evaporated copper on the O2 RIBE-modified PI consisted of three different regimes. The first regime involved chemical reaction between PI and Cu atoms; the second regime involved the mechanical interlocking of the grass-like structure of the modified PI with Cu; and in the third regime, overetching was observed. The locus of failure was also analyzed to understand the adhesion mechanism of Cu on the PI. A 10% decrease in adhesion strength was observed after thermal cycling. Furthermore, humidity tests showed that the adhesion enhancement by mechanical interlocking of the grass-like structure is not affected by the presence of moisture. 相似文献
9.
Classical molecular dynamic (MD) simulations are used to investigate the atomic-scale indentation and friction behaviors of the spherical diamond(111) or diamond(001) tip in contact with a flat copper(001) substrate. In the indentation simulations, six radii ranging from 5 to 30 nm are adopted for each tip and the contact radius is examined as a function of normal load. The results demonstrate that the contact radii calculated from the MD simulation always deviate from the continuum theory predictions and the deviation varies with the tip surface atomic structure, tip radius, and normal load. Furthermore, the atomic-scale friction behaviors are investigated using 10 nm and 30 nm diamond(111) tips sliding over the copper(001) surface with a variety of loads. Apparent atomic stick–slip behavior is observed on such ordered but incommensurate contact interface; moreover, it does not disappear with increasing tip radius. It is also revealed that the friction versus load relationship is approximately linear, which is not in agreement with the continuum theory predictions and many reported atomic force microscope (AFM) experiments. 相似文献
10.
《Ceramics International》2017,43(16):13075-13082
SiCf/SiC ceramic matrix composites (CMCs) are being widely used in the hot-sections of gas-turbines, especially for aerospace applications. These CMCs are subjected to surface recession if exposed to heat-corrosion. In this research, an alternative environmental barrier coating (EBC) is introduced to protect the SiCf/SiC CMC from high temperature degradation that is, Al film was deposited on the surface of SiCf/SiC CMC followed by heat-treatment in a vacuum. After that, a dense Al2O3 overlay was in-situ synthesized on the surface of CMC, and in this process the microstructure evolution of SiCf/SiC CMC was analyzed. The oxidation and thermal shock resistance were characterized, showing that the Al-modified SiCf/SiC CMC has a better oxidation resistance, because the dense Al2O3 overlay can hinder oxygen diffusion from environment. What is more, the water-quenching testes show that the Al-modified SiCf/SiC CMC has a good spallation resistance. 相似文献
11.
P.T. Joseph Nyan-Hwa Tai Yi-Chun Chen Hsiu-Fung Cheng I-Nan Lin 《Diamond and Related Materials》2008,17(4-5):476-480
Highly transparent ultrananocrystalline diamond (UNCD) films were deposited on quartz substrates using microwave plasma enhanced chemical vapor deposition (MPECVD) method. Low temperature growth of high quality transparent UNCD films was achieved by without heating the substrates prior to the deposition. Additionally, a new method to grow NCD and microcrystalline diamond (MCD) films on quartz substrates has been proposed. Field emission scanning electron microscopy (FESEM) and Raman spectroscopy were used to analyze the surface and structural properties of the films. The surface morphology of UNCD film shows very smooth surface characteristics. The transparent property studies of UNCD film on quartz substrate showed 90% transmittance in the near IR region. The transparent and dielectric properties of UNCD, NCD, and MCD films on quartz substrates were compared and reported. 相似文献
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文章针对电镀金刚石工具在使用过程中镀层脱落常见的三种类型,讨论了镀层脱落的影响因素,提出了解决镀层脱落的基本对策。 相似文献
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A new concept for producing freestanding diamond substrate by heteroepitaxy is proposed. Thick diamond growth by heteroepitaxy is often prevented by heteroepitaxial-strain-related substrate bowing as it leads to substrate cracking. The possibility of using diamond microneedles as a mechanism to neglect and/or exploit substrate bowing is discussed in this new concept; the self-breaking effect of the microneedles is proposed as an application to prevent the main bulk diamond layers from cracking. With an aim toward the realization of this concept, the present study shows the first two important experimental verifications through a homoepitaxial experiment with a high-pressure high-temperature diamond substrate: (1) fabrication of high-aspect-ratio diamond microneedles (2 and 100 μm in diameter and length, respectively) by a thermo-chemical etching reaction and (2) overgrowth of diamond on the microneedles with air gaps remaining between microneedles after continuous diamond film overgrowth. We also detail a growth scheme that illustrates how continuous diamond films are created from the microneedles. The strong feasibility for applying the concept in actual heteroepitaxy is suggested through the present study. 相似文献
14.
CMZ (ca. 30.0 wt.% Cu, 20 wt.% Mn, and 50 wt.% Zn) catalyst was chosen for the partial oxidation of methanol (POM) reaction. To enhance adhesion between a silicon-based reactor and catalysts, boehmite and bentonite were used as binders. Changes in conditions such as pH value, ratio of bentonite/boehmite, amount of solid contents per area of substrate, and aging time have crucial effects on adhesion and result in variable performance of catalyst in POM reaction. Regarding optimized adhesion conditions, 13 wt.% weight loss was observed and methanol conversion could be kept at ca. 80–90% of original catalyst performance in a packed-bed reactor. However, poor performance was observed in the micro-channel reactor. The methanol conversion (CMeOH), H2 selectivity (SH2), and H2 yield (YH2) achieved 58%, 67%, 5.7 × 10?6 mol/min in micro-channel reformer at 250 °C, respectively. 相似文献
15.
探索了在金刚石表面镀覆SiC涂层的工艺方法,并以机械合金化铁合金粉末为基体,采用热压烧结工艺制备了长条形金刚石刀头,测试分析了刀头的硬度、抗弯强度和微观组织.结果表明:用金刚石+Si+I2混合粉末(工艺A)、或金刚石+聚碳硅烷(PCS)溶液(工艺B)于1000℃~1200℃真空反应,均能在金刚石表面制备出SiC涂层;在基体中添加Zn、Sn等低熔点元素,会降低刀头的硬度和强度;而添加少量B4C,可以起弥散强化的作用;对金刚石先镀Ti、再镀SiC,可使刀头的硬度和强度进一步提高,最高硬度为HRB118,抗弯强度为543MPa. 相似文献
16.
金刚石化学镀铜工艺研究 总被引:6,自引:0,他引:6
介绍了金刚石化学镀铜工艺流程、工艺配方。研究了不同络合剂体系对镀液稳定性以及不同预处理方法对化学镀铜层表面形貌的影响。探讨了硫酸铜质量浓度、络合剂物质的量之比和不同pH下甲醛质量浓度对金刚石表面沉积铜速率的影响。结果表明:使用胶体钯敏化活化能显著提高金刚石表面镀铜质量,多元络合剂的加入可以增加镀液的稳定性。获得了化学镀铜最佳工艺条件:CuSO4·5H2O15g/L,甲醛(w(HCHO)=36%)15g/L,酒石酸钾钠14g/L,EDTA14.6g/L,NaOH适量,二联吡啶0.02g/L,亚铁氰化钾0.01g/L,温度(43±0.5)°C,pH=12.5。采用此工艺在金刚石颗粒表面获得了良好的镀铜层。 相似文献
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Prilled, spheroidized, and granular ammonium nitrates (AN) were coated with poly(chloro-p-xylylene) (parylene C) by a vapor deposition polymerization technique. Particles of AN with a 0.2% coating remain free flowing after long exposure to ambient conditions. The effectiveness of the coating as a moisture barrier on the three forms of AN was found to be in the order spheroids > prills > granules. Water adsorption isotherms and hygroscopicity determinations indicate that a 0.7% coating hydrophobes the surface of AN by approximately one order of magnitude. The parylene C/AN interface exhibits chemical and physical stability at elevated temperatures. 相似文献
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《Ceramics International》2020,46(6):7421-7429
Two-Axis spin coating as a new modified technique is employed to enhance the quality and surface leveling of thin films. The modified technology utilizes a synthetic centrifugal force perpendicular to the surface which generates an elevated gravity acceleration while spreading the coating on the entire wafer surface. In this paper, copper acetate sol-gel is coated by conventional and Two-Axis spin coating techniques. The coated layers are sintered in an air furnace at 275 °C. The fabricated layers are characterized by GIXRD, EDX, AFM and SEM devices. Wettability and Surface Free Energy (SFE) of sintered films using the contact angle technique are measured, and evaluated by the Owens-Wendt method. XRD and EDX spectra show a higher intensity of copper oxide phase using Two-Axis spin coating technology. AFM micrographs showed an improvement in the surface leveling within the Two-Axis spin coated layer. A comparison between the SFE of conventional and Two-Axis spin coated layers shows an increase in SFE of the layer synthesized under 200g artificial gravity acceleration. 相似文献