The Mechanism of Cube Texture Formation in Ni-7 at%W Substrate

In order to obtain the sharp cube texture,a new process,the intermediate annealing rolling technique,has been introduced to prepare the Ni7W substrate.In this paper,a cubic texture content up to 98.5%within 10°of the standard cubic orientation is obtained in the final substrate and the influence of this improved rolling technique on the cube texture formation has been discussed.The results show that the increased cube texture in the Ni7W substrate is caused by the optimized deformation texture and the increased nucleated fraction of the cube grains.

Morphology and texture of high speed galvanized coatings on interstitial free steel sheet

The morphology and texture of zinc coatings deposited on interstitial free （IF） steel sheets were investigated by means of scanning electron microscopy （SEM） and orientation distribution function. It was shown that the microstructure of the coatings consisted of thin hexagonal platelets tilted with respect to the substrate surface. Zinc coatings exhibited low angle pyramidal {11.5} nonfiber texture component resulting from epitaxial growth via two-dimensional （2D） nucleation. The 2D nucleation was attributed to severe zinc hydroxide adsorption on the substrate surface during the nucleation stage, which can inhibit three-dimensional （3D） nucleation and promote nonfiber texture. The pyramidal texture was beneficial for plastic deformation of zinc coatings because a significant amount of resolved shear stress can be obtained when the uniaxial stress is applied.

Electroplating of Ni/Co–pumice multilayer nanocomposite coatings: Effect of current density on crystal texture transformations and corrosion behavior

The present paper aims to investigate the influence of the current density in the electroplating process on the microstructure, crystal texture transformations, and corrosion behavior of Ni/Co pumice multilayer nanocomposite coatings. The Ni/Co pumice composite coatings were prepared by deposition of Ni, followed by the simultaneous deposition of pumice nanoparticles (NPs) in a Co matrix via an electroplating process at various current densities. Afterward, the morphology, size, topography, and crystal texture of the obtained samples were investigated. Furthermore, electrochemical methods were used to investigate the corrosion behavior of the produced coatings in a solution of 3.5wt% NaCl. The results indicated that increasing the plating current density changed the mechanism of coating growth from the cell state to the column state, in- creased the coating thickness, roughness, and texture coefficient (TC) of the Co (203) plane, and reduced the amount of pumice NPs incorporated into the Ni/Co pumice composite. The electrochemical results also indicated that increasing the current density enhanced the corrosion resistance of the Ni/Co pumice composite.

Effects of Chloride Ion on the Texture of Copper and Cu-ZrB_(2) Coatings Electrodeposited from Copper Nitrate Solution in Different Plating Modes

For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current （DC） and pulse current （PC） conditions. Copper deposits are strongly 〈220〉 textured in DC plating with and without chloride ion. While in PC condition, the predominant texture shifts from 〈220〉 to 〈200〉 as the chloride ion concentration exceeds 20 mg/l. The addition of ZrB2 particles enhances the cathodic polarization of copper deposition, which improves the growth of （111） plane. However, this improvement can be eliminated by further addition of chloride ion.

Absorption and Permeability of Air-jet Textured Glass Fiber Yarn and Its Fabric for Resin

The Absorption and permeability of air-jet textured glass fiber yarn and its fabric and bonded tenacity of the fabric have been studied in relation to the main parameters, air supplied pressure and overfeed ratio.It has been observed that increasing the level of main parameters improves the coated ratio of the textured yarn and its fabric as well as the bonded tenacity of the fabric made of textured yarn. Comparison of absorption or permeability between textured and supplied yarns, and comparison of absorption or permeability and bonded tenacity between the two kinds of fabrics have been elucidated.

Crystalline texture evolution, control of the tribocorrosion behavior, and significant enhancement of the abrasion properties of a Ni-P nanocomposite coating enhanced by zirconia nanoparticles

This paper describes an investigation of the effect of ZrO2 nanoparticles on the abrasive properties,crystalline texture developments,and tribocorrosion behavior of Ni-P nanostructured coatings.In the investigation,Ni-P and Ni-P-ZrO2 nanostructured coatings are deposited on St52 steel via the electroless method.Transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD),energy dispersive spectroscopy(EDS),cyclic-static polarization tests in 3.5wt%NaCl solution,the tribocorrosion test(by back-and-forth wear in electrochemical cell),and the microhardness test using the Vickers method were performed to characterize and analyze the deposited coatings.The results of this study showed that the addition of ZrO2 nanoparticles to the Ni-P electroless bath produced the following:a sharp increase in wear and hardness resistance,the change of the wear mechanism from sheet to adhesive mode,the reduction of pitting corrosion resistance,significant reduction in the tribocorrosion protective properties,change in the preferred orientation of the crystalline texture coating from(111)to(200),increase in the sedimentation rate during the deposit process,and a sharp increase in the thickness of the Ni-P nanostructured coatings.

Micromorphology and texture of niobium coating electrodeposited in NaCl−KCl−CsCl molten salt system

A low-toxicity and environment-friendly NaCl−KCl−CsCl−K_(2)NbF_(7) system was used to prepare Nb coatings on Mo substrates.The effects of temperature,current density and electrodeposition time on the micromorphologies and textures of the electrodeposited Nb coatings were studied.The results showed that Nb coatings obtained at 30−70 mA/cm^(2) in the temperature range of 700−750℃ were continuous and compact,with a hardness range of 2.16−2.45 GPa.As the columnar crystals grew with time,the preferential growth orientations of the Nb coatings changed from<200>to<211>and then became disordered.With increasing polarization,the morphologies of the Nb coatings changed from hexagonal star-like surface to conical or pyramid-like surface.

Evolution of deformation-induced texture and surface microstructure of nickel coating under deep cup-drawing process

The deformation texture and surface microstructure of nickel coating induced by deep cup-drawing were studied by X-ray diffractometry and SEM. The steel sheet with nickel coating was firstly punched to designed degree of cup shapes. Then the texture of the coating was determined by XRD and the surface microstructure was observed by SEM. The results indicate that,the nickel coating material includes three kinds of textures,i.e. Ni(111),Ni(200) and Ni(220). After cup-drawing deformation,there doesn't appear new texture component for nickel coatings but the change of the intensity of the deformation textures. In the cup-deformation process,the two kinds of main textures Ni(111) and Ni(200) increase in the first and second cup-drawing procedures and then reduce quickly in the third and fourth drawing procedure. However,for the Ni(220) texture,it always increases in whole cup-drawing procedures. With the increase in the drawing,there are some cracks to be found,but not delamination. This shows that nickel coating and the substrate have a good combinable performance.

Computation of deformation-induced textures in electrodeposited nickel coating

The deformation-induced textures in electrodeposited nickel coating were numerically studied. The finite element method (FEM) for polycrystalline was developed based on Taylor model. Then the deformation-induced textures in electrodeposited nickel coating with initial random and lamellar texture were simulated under tensile load. It is found that the initial textures significantly influence the deformation-induced textures. For nickel coating with the initial random textures, when the tensile strain is about 40%, there are some lamellar textures. For nickel coating with the initial lamellar textures, the lamellar texture is more intensity with the increase of the tensile strain. With the increase of the tensile strain in the coating, there are more pronounced element distortion and a more inhomogeneous deformation. Due to the different crystal orientations, the grain-scale roughness is observed. With increasing tensile strain in the coating, the surface grain-scale roughness increases on the free surface. The surface roughness of the coating with initial random texture is lower than that with the initial lamellar texture.

Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition （PVD） TiN coatings were used, such as, in-lined （IN） and staggered （ST） spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of-180 V and slid for 4, 8 and 11 h respectively, were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.

Tribological behavior of polydopamine/polytetrafluoroethylene coating on laser textured stainless steel with Hilbert curves

Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates.Two different texture path segment lengths(12 and 24 μm)and four different laser power percentages(5%,10%,15%,and 20%)were investigated.The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene(PDA/PTFE)coatings for tribological property assessment.The effects of texture density(texture area coverage)and laser power on the durability and friction of the coated surfaces were studied.Laser texturing the substrates improved the coating durability up to 25 times,reduced the friction coefficient,and prevented coating global delamination.The textures fabricated with a laser power of 15%and a texture path segment length of 12 μm yielded the best coating durability.The textures provided the interlocking for the PTFE coating and thus prevented its global delamination.Furthermore,the PTFE inside the texture grooves replenished the solid lubricant worn away in the wear track and prolonged the coating wear life.

Sliding wear characteristics of solid lubricant coating on titanium alloy surface modified by laser texturing and ternary hard coatings

Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because ofits severe adhesive wear tendency.The surface modifications through texturing and surface coating were used to enhance the surfaceproperties of the titanium alloy substrate.Hard and wear resistant coatings such as TiAlN and AlCrN were applied over texturedtitanium alloy surfaces with chromium as interlayer.To improve the friction and wear resisting performance of hard coatings further,solid lubricant,molybdenum disulphide(MoS2),was deposited on dimples made over hard coatings.Unidirectional sliding weartests were performed with pin on disc contact geometry,to evaluate the tribological performance of coated substrates.The tests wereperformed under three different normal loads for a period of40min at sliding velocity of2m/s.The tribological behaviours ofmulti-layer coatings such as coating structure,friction coefficient and specific wear rate were investigated and analyzed.The lowerfriction coefficient of approximately0.1was found at the early sliding stage,which reduces the material transfer and increases thewear life.Although,the friction coefficient increased to high values after MoS2coating was partially removed,substrate was stillprotected against wear by underlying hard composite layer.

Analysis of the coated and textured ring/liner conjunction based on a thermal mixed lubrication model

For the ring/liner conjunction, well‐designed surface texturing has been regarded as a potential means to improve its tribological performance, as well as the application of coating. However, so far most researchers focused on the one of these aspects. In this study, the combined effect of coating and texturing on the performance of ring/liner conjunction is numerically investigated. A thermal mixed lubrication model is presented. The effects of the coating's thermal and mechanical properties on the tribological performance are studied under the cold and warm engine operating conditions. Along with the increasing coating thickness, the effects of the coating's thermal properties on friction loss are found to be significant, as well as the effects of the coating's mechanical properties. It is also found that a soft coating with a lower thermal inertia has a greater ability to reduce the friction loss of the textured conjunction.

Effect of Obliquely Deposited on Microstructure and Texture Evolution in TBCs Fabricated by EB-PVD Process

The effects of vapor incidence angle (VIA) on the microstructure and crystallographic texture of EB-PVD TBC under rotation mode have been experimentally examined by SEM,X-ray diffraction and pole figures in this article.It is demonstrated that VIA strongly influences the angle of columnar grains and crystallographic texture of TBC.The inclination of columnar grains depends on the VIA and the inclination angle follows the tangent rule deposited at 900℃,but the inclination angle of columnar deposited at 800℃ unconformity the tangent rule.

Optical and electrical properties of porous silicon layer formed on the textured surface by electrochemical etching

Porous silicon （PS） layers were formed on textured crystalline silicon by electrochemical etching in HF- based electrolyte. Optical and electrical properties of the TMAH textured surfaces with PS formation are studied. Moreover, the influences of the initial structures and the anodizing time on the optical and electrical properties of the surfaces after PS formation are investigated. The results show that the TMAH textured surfaces with PS formation present a dramatic decrease in reflectance. The longer the anodizing time is, the lower the reflectance. Moreover, an initial surface with bigger pyramids achieved lower reflectance in a short wavelength range. A minimum reflectance of 3.86% at 460 nm is achieved for a short anodizing time of 2 min. Furthermore, the reflectance spectrum of the sample, which was etched in 3 vol.% TMAH for 25 min and then anodized for 20 min, is extremely flat and lies between 3.67% and 6.15% in the wavelength range from 400 to 1040 nm. In addition, for a short anodizing time, a slight increase in the effective carrier lifetime is observed. Our results indicate that PS layers formed on a TMAH textured surface for a short anodization treatment can be used as both broadband antireflection coatings and passivation layers for the application in solar cells.

Texture of Magnetron Sputter-deposited 1Cr18Ni9Ti Stainless Steel

Phase transformation of magnetronsputter deposited 1Cr18Ni9Ti stainlesssteel has been studied [1]. A single bccphase was formed as the substrate tempera-ture kept below 370℃. The deposits exhibited different textures,which depended on the position of the subs-trates relative to the target: the predominant(110) planes were parallel to the surfaceof substrate which was parallel to the target:the predominance was weakened whenthe substrate surface was vertical to the

Three-dimensional numerical simulation of soft/hard composite-coated textured tools in dry turning of AISI 1045 steel

A structural model of a soft/hard compositecoated textured (SHCCT) tool was proposed and substantiated by a three-dimensional numerical simulation. Its dry turning performance as applied to AISI-1045 steel was analyzed via three-factor five-level orthogonal experiments for different coating parameters, including coating thickness, coating material, and thickness ratio of the soft and hard coatings. In addition, the cutting performance of the proposed SHCCT tool was compared with those of uncoated non-textured, coated non?textured, and uncoated textured tools, and its superiority was proved by the significant reductions in the cutting force, and specifically, the cutting temperature. The optimal results were provided by the SHCCT tool with a WS2/ZrN soft/hard composite coating, a 0.9:0.1 thickness ratio of the above ingredients, and a total coating thickness of 0.5 μm.

Preparation of a Cube-Textured Ni-7at.%W Based Template Used for Coated Conductors

Although Ni-W substrate with high W content (>5at.%) substrates have been developed successfully, the quality of cube texture and grain boundary, as well as extensive applications in coated conductors should be further improved. In the present work, once intermediate annealing treatment (IAT) at 500°C for 2 h has been employed to optimize the deformation and recrystallization textures in Ni-7at.%W (Ni7W) substrates. As a result, competitive high cube texture content (<10°) and low angle grain boundary fraction (<10°) were realized (98.5% and 91.2%, respectively). A Gd2Zr2O7 (GZO) buffer layer with strong cube texture and high-quality surface deposited successfully on the Ni7W substrate using the chemical solution deposition method, demonstrating the advanced GZO/Ni7W template is promising for coated conductors.

内燃机活塞环材料及表面处理技术研究现状与发展趋势

活塞环是内燃机中重要的零部件之一,该部件的摩擦损耗占内燃机总摩擦损失的26%。因此,活塞环材料的选用及其表面处理研究对于优化提升内燃机性能、延长服役寿命具有重要意义。简单介绍并总结了内燃机活塞环常用材料及其发展趋势,详细综述了激光表面织构技术、表面涂层技术以及表面复合技术在内燃机活塞环减摩抗磨方面的研究和应用现状。其中,激光表面织构技术(LST)可起到接纳磨屑、保持油膜等作用,从而降低活塞环表面摩擦和磨损,但由于织构形貌和几何参数特征对摩擦学性能的影响较为复杂,仍需结合实际工况进一步研究并优化。以镀铬、热喷涂、气相沉积及激光熔覆为代表的涂层技术也常用于活塞环的表面强化处理,但涂层材料种类繁多,难以形成统一的行业标准进而规模应用。此外,通过合理复合多种表面处理技术,比如微弧氧化与电泳沉积复合、超声滚压与离子渗氮技术复合、磁控溅射和低温离子渗硫复合等,可实现优势互补、发挥协同作用,有效改善接触表面的摩擦性能,为活塞环的减摩增寿研究开拓了新的思路。最后对未来活塞环材料开发应用及其减摩抗磨方面的研究发展进行了展望。

涂层刀具圆孔与直槽混合微织构激光制备工艺研究

针对刀具微织构激光制备质量欠佳的问题,文章研究了激光工艺参数对混合型织构表面形貌、几何尺寸和表面成分的影响规律。实验结果表明:对于涂层刀具表面圆孔和直槽混合微织构的制备,较为合理的激光参数为:加工次数N=6,扫描速度v=10 mm/s,激光功率P=20 W,激光频率f=120 kHz。涂层刀具织构底部和侧壁的结构以氧化物为主,在合理选择激光参数的情况下,刀具表面织构以外的涂层不会被破坏。通过涂层刀具混合微织构激光制备工艺的研究发现,织构宽度和深度的控制是制备微织构刀具的关键,所得规律为提高刀具织构加工质量提供参考依据。