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金属间化合物NiAl-Ta-Cr高速火焰喷涂工艺及涂层特性

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稀有金属材料与工程 2006年第6期35卷 974-977页

作者：赵力东贺定勇 k.bobzin E.Lugscheider RWTHAachen D-52070AachenGermany 北京工业大学

采用高速火焰(HVOF)热喷涂工艺制备了金属间化合物NiAl-Ta-Cr涂层。研究了喷涂距离、氧气流量以及燃气流量等工艺参数对涂层组织结构和性能的影响。用光学显微镜观察涂层的组织结构并测定涂层的孔隙率,用LECOTC316气体抽提仪检测涂层的... 详细信息

采用高速火焰(HVOF)热喷涂工艺制备了金属间化合物NiAl-Ta-Cr涂层。研究了喷涂距离、氧气流量以及燃气流量等工艺参数对涂层组织结构和性能的影响。用光学显微镜观察涂层的组织结构并测定涂层的孔隙率,用LECOTC316气体抽提仪检测涂层的氧含量。结果表明,氧气流量、喷涂距离等工艺参数对涂层性能的影响比较明显。随着喷涂距离的增加,涂层的氧含量降低;O/H比率越大,涂层的氧含量越高,而孔隙率降低,沉积率越高。涂层经1100℃,4h真空热处理后,变得更加均匀和致密,孔隙率降低,但涂层的硬度有所降低。涂层经1100℃,100h高温氧化处理后,在涂层表面生成了连续的氧化铝氧化层,硬度比真空退火后略有下降。

关键词：高速火焰喷涂 NiAl-Ta-Cr金属间化合物喷涂参数涂层

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铝基铜焊合金冷喷研究

机械工人（热加工） 2007年第5期31卷 20-23页

作者： E.Lugscheider k.bobzin L.Zhao F.Ernst J.Zwick 德国RWTH亚琛大学表面工程研究院

冷喷涂工艺具有喷涂材料低氧化性与喷涂过程中基体和粒子表面氧化膜破裂的特性，因此广泛应用于铜焊技术。目前研究中，两种铜焊合金AlSi12和AlSi10Cu4可通过冷喷涂工艺喷涂在6063和3003铝合金上。喷涂参数对粒子速度的影响可通过DPV200... 详细信息

冷喷涂工艺具有喷涂材料低氧化性与喷涂过程中基体和粒子表面氧化膜破裂的特性，因此广泛应用于铜焊技术。目前研究中，两种铜焊合金AlSi12和AlSi10Cu4可通过冷喷涂工艺喷涂在6063和3003铝合金上。喷涂参数对粒子速度的影响可通过DPV2000研究。喷涂材料和参数对涂层形成和涂层微观结构的影响已做研究。

关键词： 3003铝合金铜焊喷涂材料铝基喷涂工艺粒子速度涂层形成表面氧化

HVAFWC-Co-Cr涂层的研究和表征以及与电镀硬质铬涂层的对比

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热喷涂技术 2014年第2期6卷 61-65,19页

作者： k.bobzin N.kopp T.Warda M.Schfer A.Verstak 袁建鹏亚琛大学表面工程研究所德国加利福尼亚州贝尼西亚市kermetico公司美国

新型超音速火焰喷涂系统（HVAF）主要用于生产硬质合金和金属合金涂层。该过程类似于传统的超音速氧焰喷涂（HVOF）工艺,但采用空气代替氧气为助燃剂。因此,超音速火焰喷涂工艺的火焰温度更低（～2300k）,从而最大限度地减低了喷涂材料... 详细信息

新型超音速火焰喷涂系统（HVAF）主要用于生产硬质合金和金属合金涂层。该过程类似于传统的超音速氧焰喷涂（HVOF）工艺,但采用空气代替氧气为助燃剂。因此,超音速火焰喷涂工艺的火焰温度更低（～2300k）,从而最大限度地减低了喷涂材料的氧化和热失效。该工艺粒子飞行速度可达1000米/秒。本文对HVAF WC-CoCr涂层进行了研究,采用截面法对涂层显微组织形貌等特性进行了观测和讨论,对涂层的表面质量和相成分进行了分析。此外,还测量了涂层的硬度,通过电化学腐蚀试验表征了涂层的腐蚀行为。最后,将该涂层的检测结果与电镀硬铬涂层进行了比较和分析。

关键词： HVAF WC-Co-Cr涂层涂层微观结构抗腐蚀性能

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热喷涂铁基材料在印刷业耐磨防护上的应用

热喷涂技术 2011年第4期3卷 58-63页

作者： k.bobzin T.Schlaefer T.Warda M.Schaefer Aachen/D 赵晓东高峰不详

与典型的耐磨防护材料（如金属陶瓷）相比,铁基材料不仅对人体更健康、更具有环境友好性,而且在材料成本和加工费用方面,其经济效益也更明显。当喷涂粉末的粒度非常细时（小于15um）,所获得的涂层表面更光滑,而且能获得相对较薄的、致... 详细信息

与典型的耐磨防护材料（如金属陶瓷）相比,铁基材料不仅对人体更健康、更具有环境友好性,而且在材料成本和加工费用方面,其经济效益也更明显。当喷涂粉末的粒度非常细时（小于15um）,所获得的涂层表面更光滑,而且能获得相对较薄的、致密的、接近净成形的涂层。这就会降低涂层材料及加工的费用。本研究采用大气等离子（APS）喷涂粒度为5~15um的铁基细粉制备印刷行业耐磨防护涂层。为了避免细的铁基粉末在喷涂过程中的氧化问题,本研究设计并制备了一个防护罩。在APS设备上安装了这种特殊的防护罩以防止铁基材料的氧化;本文对所制备涂层的显微组织、显微硬度、化学成分、相组成和表面粗糙度进行了分析,同时介绍了这种涂层所产生的经济效益。

关键词：铁基粉末等离子喷涂耐磨性抗氧化

等离子体转移弧法制备的气缸内壁涂层和新型活塞环对新一代发动机的摩擦性能改进

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热喷涂技术 2012年第3期4卷 56-62页

作者： L.Schramm C.Verpoort Aachen/D A.Schwenk Luckenbach/D k.bobzin N.Bagcivan T.Schlafer S.Theiβ k.Yilmaz 袁建鹏北京矿冶研究总院北京100160 北京市工业部件表面强化与修复工程技术研究中心北京100160

为了控制气候变化,欧盟已经承诺,到2020年,CO2气体的排放量将比1990年减少30%。二氧化碳总排放量的20%来源于交通,其中道路交通占据了交通气体排放的84%以上。为了实现二氧化碳减排的目标,汽车行业不得不执行更严格的排放标准。汽车行... 详细信息

为了控制气候变化,欧盟已经承诺,到2020年,CO2气体的排放量将比1990年减少30%。二氧化碳总排放量的20%来源于交通,其中道路交通占据了交通气体排放的84%以上。为了实现二氧化碳减排的目标,汽车行业不得不执行更严格的排放标准。汽车行业减排只有通过减轻车身重量和提高发动机和传动系统的效率方可实现。内燃机中接近50%的能量用来克服活塞环与气缸内壁之间的摩擦阻力,因此气缸内壁以及活塞环上均被涂上新型的低摩擦材料,以减少该部位带来的能量损失。论文中采用线性往复摩擦试验机表征气缸壁和活塞环间的摩擦行为,以便找出最佳的涂层组合。

关键词：等离子体转移弧气缸涂层活塞环摩擦

Influence of Microstructures on Thermal Shock and Sintering Behavior of YSZ-based Thermal Barrier Coatings

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表面技术 2019年第4期48卷 28-33页

作者： kirsten bobzin Lidong Zhao Mehmet ?te Tim k?nigstein Surface Engineering Institute RWTH Aachen University

In this study, two thermal barrier coatings based on YSZ were produced by using a commercially available agglomerated and sintered powder and a special spray powder prepared by high energy ball milling. Both thermal barrier coatings exhibited similar overall porosities, but significantly different microstructures. Application of the special spray powder prepared by high energy ball milling led to a microstructure with numerous inclusions of semi-molten agglomerates, which introduced a plethora of clusters of fine pores into the coating and several more microstructural defects. This microstructure resulted in a significantly better thermal shock behavior compared to the conventional thermal barrier coating. The heat treatment of both thermal barrier coatings atθ=1150℃for t=100 h led to a sintering of both coatings. The results were reduced overall porosity and significantly increased fracture toughness. A correlation between the fracture toughness of both coatings after the heat treatment and the thermal shock life time could not be identified.

关键词： thermal barrier coating ZrO2-7%Y2O3 high energy ball milling thermal shock

Wide gap active brazing of ceramic-to-metal-joints for high temperature applications

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Frontiers of Mechanical Engineering 2014年第1期9卷 71-74页

作者： k. bobzin Zhao, N. kopp S. Samadian Anavar Surface Engineering Institute RWTH Aachen University Germany

Applications like solid oxide fuel cells and sensors increasingly demand the possibility to braze ceramics to metals with a good resistance to high temperatures and oxidative atmospheres. Commonly used silver based active filler metals cannot fulfill these requirements, if application temperatures higher than 600℃ occur. Au and Pd based active fillers are too expensive for many fields of use. As one possible solution nickel based active fillers were developed. Due to the high brazing temperatures and the low ductility of nickel based filler metals, the modification of standard nickel based filler metals were necessary to meet the requirements of above mentioned applications. To reduce thermally induced stresses wide brazing gaps and the addition of A1203 and WC particles to the filler metal were applied. In this study, the microstructure of the brazed joints and the thermo-chemical reactions between filler metal, active elements and WC particles were analyzed to understand the mechanism of the so called wide gap active brazing process. With regard to the behavior in typical application oxidation and thermal cycle tests were conducted as well as tensile tests.

关键词： wide gap active brazing nickel filler metals,high temperature application WC A1203

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 193-208页

作者： k.MUHAMMAD M.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of Mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(MHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in MATHEMATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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Influence of direct electric current on wetting behavior during brazing

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Frontiers of Mechanical Engineering 2020年第3期15卷 496-503页

作者： kirsten bobzin Wolfgang WIETHEGER Julian HEBING Lidong ZHAO Alexander SCHMIDT Riza ISkANDAR Joachim MAYER Surface Engineering Institute(IOT) RWTH Aachen University52072 AachenGermany Central Facility for Electron Microscopy RWTH Aachen University52074 AachenGermany

The wetting behavior of liquid metals is of great importance for many processes. For brazing, however, a targeted modification beyond the adjustment of conventional process parameters or the actual set-up was not possible in the past. Therefore, the effect of direct electric current along the surface of a steel substrate on the wetting behavior and the formation of the spreading pattern of an industrial nickel-based filler metal was investigated at a temperature above T = 1000 °C in a vacuum brazing furnace. By applying direct current up to I = 60 A the wetted surface area could be increased and the spreading of the molten filler metal could be controlled in dependence of the polarity of the electric current. The electric component of the Lorentz force is supposed to be feasible reasons for the observed dependence of the electrical polarity on the filler metal spreading direction. To evaluate the influence of the electric current on the phase formation subsequent selective electron microscope analyses of the spreading pattern were carried out.

关键词： brazing electric current assisted wetting Lorentz force