金刚石表面超声波化学镀铜—镍双层金属

研究了金刚石表面超声波化学镀Cu-Ni双层金属工艺及其对金刚石性能的影响，并与单独镀Cu，单独镀Ni金刚石进行了对比。结果表明，在金刚石表面化学镀Cu后，再镀Ni,其性能比单镀Cu者高，比单镀Ni者低，介于两者之间，但更接近于镀Ni者。     

不同镀层金刚石与铜基粉末烧结制备的锯片刀头性能及机理

为了研究金刚石表面不同镀层对锯片刀头性能的影响及作用机理,分别对金刚石作了化学镀Ni、真空微蒸发镀Ti及Ti-Ni复合镀处理,并与铜基粉末混合烧结制备了锯片刀头。分别采用L30W/TMP扫描电镜、自制的3点抗弯机和热蚀法,对锯片刀头的锋利度、抗弯强度、耐热蚀性进行了探讨。结果表明:金刚石镀覆后制备的锯片切削性能、胎体对金刚石的把持力比金刚石锯片均有不同程度的提高;高温下,镀覆层对金刚石起到了一定的保护作用,镀Ni金刚石的锯片金刚石脱落较严重,镀Ti金刚石锯片的锋利度提高不大,Ti-Ni复合镀金刚石锯片切割速度最快,较前2种分别提高了67%和56%,且加工质量最好。金刚石表面Ti-Ni复合镀是提高铜基金刚石锯片性能的最有效措施之一。     

超声波重复化学镀Cu—Ni合金对金刚石性能的影响

研究了金刚石表面超声波重复化学镀Ｃｕ－Ｎｉ合金工艺及其对金刚石性能的影响。结果表明：超声波重复化学镀是一种有效增加镀层厚度的化学镀覆新工艺。每次镀１ｈ，镀覆４次，金刚石增重１２０％，采用这些新工艺，金刚石的单颗粒抗压强度可提高近１倍，氧化可提高１００℃左在。     

人造金刚石控制增量化学镀镍工艺的研究

研究了人造金刚石表面控制增量化学镀镍的工艺及化学镀镍层对金刚石性能的影响。结果表明，通过补加镀液中消耗的主盐和还原剂对金刚石进行连续化学镀，可以由化学镀的时间来控制金刚石表面的增量；化学镀镍层能显著提高金刚石的抗压强度和抗氧化温度。     

金刚石单晶真空蒸镀铬的工业化应用

应用真空蒸镀处理技术，在金刚石单晶表面蒸镀金属铬层，并在真空高温条件下，部分铬与金刚石键合生成Cr7C3，有效地提高金刚石表面对金属粘结剂的粘结力。该蒸镀技术工艺简单、经济，可以在工业化生产中应用。结果表明，经真空蒸镀处理后，金刚石制品的寿命提高了50％～100％。     

金刚石化学镀Cu-Ni-P工艺的研究

为获得高耐磨、抗蚀、有良好导电性能的化学镀合金层,对化学镀Ni-Cu-P工艺进行了研究,选择的基础配方和工艺条件为:65～95 mg/L硫酸铜,15～40 g/L硫酸镍,15～30 g/L次磷酸钠,5～20 g/L柠檬酸钠,15～30 g/L氯化铵,12～35 mg/L硝酸钾;pH值4.5～7.6,温度75～95 ℃,施镀时间15～35 min.探讨了镀液组成、pH值和施镀时间对镀层沉积速度的影响,并通过X射线衍射分析了镀覆后金刚石的抗氧化性能.结果表明,用本工艺在金刚石上化学镀Cu-Ni-P层,所得镀层具有较高的耐磨性,镀层经高温热处理后,金刚石的抗氧化性能得到进一步提高.     

金刚石表面金属化的研究现状

主要介绍了金刚石表面金属化的原理、模型;金刚石表面金属化的几种制备方法:化学镀加电镀、真空镀、盐浴镀以及各种方法的优缺点,并综述了国内外金刚石表面金属化的研究进展;同时归纳总结了金刚石表面金属化的表征方法.     

PVC材料Ni-Co合金电镀工艺

以硫酸镍和无水氯化钴为镀液主盐，以硼酸为主络合剂，研究了对经化学镀预处理后的ＰＶＣ材料进行镍钴合金电镀的工艺条件及影响因素。结果表明，在电流密度为１．５～３．０Ａ／ｄｍ２的条件下，适当调节镀液的ｐＨ值及温度，可获得稳定的青白色合金镀层及令人满意的光泽度。     

化学镀Ni-B和Ni-W-P／金刚石-（CF）n复合镀层及性能研究

针对恶劣环境下工作的雷达支撑腿需要表面耐磨、耐蚀和具有自润滑性能的要求,本文以自润滑耐磨、耐蚀复合镀层制备技术为研究目标,确定采用复合化学镀的方法,以45#钢为基体材料、Ni-B为基底合金、Ni-W-P为基质合金、添加耐磨微粒人造金刚石微粒和固体润滑刑（CF）n微粒,镀制Ni-B和Ni-W-P／金刚石一（CF）n双层复合镀层的制备工艺。实验结果表明：该工艺得到的Ni-B和Ni-W-P／金刚石-（CF）n双层复合镀层表面光亮,质感均匀,粗糙度为Ra0．2;镀层结合力良好;耐蚀性优良;经过相同次数磨损试验,磨损量仅为未镀试件的21．2％。     

PVC材料Ni—Co合金电镀工艺

以硫酸镍和无水氯化钴为镀液主盐，以硼酸为主络合剂，研究了经化学镀预处理的ＰＶＣ材料进行了镍钴合金电镀的工艺条件及影响因素，结果表明，在电流密度为１．５－３．０Ａ／ｄｍ＾２的条件下，适当调节镀液的ｐＨ值及温度，可获得稳定的青白色合金镀层及令人满意的光泽度。     

CVD nanocrystalline diamond coatings on Ti alloy: A synchrotron-assisted interfacial investigation

Diamond coating on Ti-6Al-4V alloy was carried out using microwave plasma enhanced CVD with a super high CH₄ concentration, and at a moderate deposition temperature close to 500 °C. The nucleation, growth, adhesion behaviors of the diamond coating and the interfacial structures were investigated using Raman, XRD, SEM/TEM, synchrotron radiation and indentation test. Nanocrystalline diamond coatings have been produced and the nucleation density, nucleation rate and adhesion strength of diamond coatings on Ti alloy substrate are significantly enhanced. An intermediate layer of TiC is formed between the diamond coating and the alloy substrate, while diamond coating debonding occurs both at the diamond-TiC interface and TiC-substrate interface. The simultaneous hydrogenation and carburization also cause complex micro-structural and microhardness changes on the alloy substrates. The low deposition temperature and extremely high methane concentration demonstrate beneficial to enhance coating adhesion strength and reduce substrate damage.     

Ti镀层对金刚石-铜基合金复合材料界面结构和性能的作用

为了提高金刚石-铜合金复合材料的界面粘结强度,本文用差热分析(DTA)、X射线衍射分析、SEM观察及磨削试验研究了金刚石表面的Ti镀层对金刚石-铜基合金复合材料界面结构及性能的影响.结果表明,在600～1200℃镀Ti层与金刚石发生界面反应,在金刚石表面外延生成岛状TiC,从而实现了金刚石与铜基合金的冶金结合.镀Ti金刚石与铜合金的粘结强度可达8×107Pa.用镀Ti金刚石制成的铜基合金磨块对花岗岩的磨削比与不镀钛金刚石相比提高30%.     

Cr Powder-Activated Induction Brazing of Diamond Grits with Ag-Cu-Zn Alloy

Cr powder was used to activate the brazing of diamond grits with Ag-Cu-Zn alloy. The interfacial microstructure among the brazing alloy, the diamond grit, and the steel substrate is also examined by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction. It was found that Cr₇C₃ formed between diamond and Ag-Cu-Zn alloy was the main reason for improving the wettability of Ag-Cu-Zn alloy to the diamond and the strong bonding of diamond grit. A graphitization layer was formed on the surface of diamond under high temperature brazing. Bonding strength of the brazed diamond grits were also examined by a grinding test.     

Mi_（70）Mn_（25）Co_5触媒合金C－N－B三元共渗研究

研究了合成人造金刚石用Ｎｉ（７０）Ｍｎ（２５）Ｃｏ５触媒合金Ｃ、Ｎ、Ｂ三无共渗及其对合成人造金刚石质量和产量的影响，并与单独渗Ｃ、渗Ｎ、渗Ｂ合金进行了对比。结果表明，该合金三元共渗比单独渗合成的人造金刚石的性能更高。单产比渗Ｃ者低，比渗Ｎ、渗Ｂ者高，接近于原始合金。     

DEPOSITION OF DIAMOND FOR CUTTING TOOL APPLICATIONS

The poor adhesion of diamond film to substrates is one of the major problems for practical use in a cutting tool (1-4). in this study, sintered tungsten carbide (WC) body without Co metal, not cemented carbide, was used as the substrate (5), and the effects of surface decarburization of the substrate for improvement in the adhesion of diamond films were investigated. The surface decarburization and diamond coating were carried out in a microwave plasma CVD system. From the results of several adhesion tests, including the cutting tests, it is concluded that the good adhesion is obtained by surface decarburization of the substrate before diamond coating. The reasons for improvement in adhesion are considered by observing the interface structure between the film and the substrate. The damage mechanism of diamond coating on cutting an AI-18%Si alloy with increasing cutting speed is also discussed.     

Investigation of Fatigue Failures of Titanium Alloy Blades Used in Compressor Modules of Aeroderivative Industrial Gas Turbines

Gas turbine axial compressor blades are designed to withstand cyclic stress loading resulting of modal vibrations. However, when surface suffers from foreign object damage, a fatigue crack is likely to initiate. In this paper two failure case-studies of titanium alloy used for aeroderivative gas turbine compressor blades are presented. Both are related to a failure of first stage compressor blades coming from different turbine power ranges. Observed cracks were found at blade spans corresponding to modal vibrations.     

触媒合金渗硼对合成人造金刚石性能的影响

本文研究了触媒合金渗硼对合成人造金刚石性能的影响。结果表明，采用渗硼触媒合成金刚石，可提高金刚石的抗压强度、耐热性和优质粗晶粒百分比，但却使金刚石的单次合成产量降低。     

Laser ablation of diamond fibres and a diamond fibre metal matrix composite

Continuous chemical vapour-deposited diamond-coated fibres with tungsten wire or SiC fibre cores are attractive for reinforcing metals and ceramics. The fibres have been embedded in Ti-6A1-4V alloy to produce a diamond fibre-reinforced composite. Both the fibres and the composite material are extremely difficult to cut without damage by conventional mechanical methods. The use of a Nd-YAG laser to cut these materials is described.     

界面反应对Cu35Ni25Co25Cr15多主元合金/金刚石复合材料磨损性能的影响

金刚石超硬磨具在高端芯片加工、3C陶瓷等领域发挥的作用日益重要,粘结相与金刚石的界面结合情况在很大程度上影响了金刚石超硬复合材料的力学和磨损性能。为了研究粘结相和金刚石的界面结合情况,采用放电等离子烧结方法制备了Cu₃₅Ni₂₅Co₂₅Cr₁₅多主元合金/金刚石复合材料,通过热力学计算和实验研究了粘结相和金刚石颗粒的界面反应。结果表明：烧结过程中,金属粘结相中的Cr元素与金刚石在界面处发生了化学反应,生成Cr-C化合物,且Cr-C化合物层的厚度随着烧结温度的升高而增加。当烧结温度达到950℃时,Cr-C化合物反应层均匀连续,厚度大约为1.1μm。复合材料粘结相与金刚石颗粒的粘结系数随着Cr-C化合物层厚度的增加而增大。摩擦磨损测试表明,在900℃和950℃烧结的样品表面,粘结相在摩擦过程中首先被磨除,金刚石随后露出,而Cr-C界面反应层有助于保持对金刚石颗粒的把持能力,提高复合材料的磨削性能。因此,适当的界面反应可提升金刚石复合材料的服役性能。     

Experimental investigation on induction brazing of diamond with Ni-Cr hardfacing alloy under argon atmosphere

In recent years direct brazing of a monolayer of diamond crystals on a steel substrate with active filler metals has gained tremendous importance in the industry, with a view to developing tools which can out-perform the conventional galvanically bonded diamond tools. An existing proprietary process uses a specially prepared Ni-Cr filler metal to facilitate its application on a steel substrate. The brazing is done either in a vacuum or a dry hydrogen furnace. The present study has shown that a commercially available Ni-Cr hardfacing alloy, flame-sprayed on a steel substrate with an oxyacetylene gun, could be used for direct brazing of diamond particles. Induction brazing was carried out in an argon atmosphere only for short durations. During brazing under such conditions, the chromium present in the alloy segregated preferentially to the interface with diamond to form a chromium-rich reaction product promoting the wettability of the alloy. It has been further revealed that under a given set of brazing conditions, the wettability of the Ni-Cr hardfacing alloy towards diamond grits primarily depended on its layer thickness. Such dependence resulted in significant variation of topographical features of the tool and its wear mode in simulated grinding tests.