用于蓝宝石材料加工的新型超精密抛光技术及复合抛光技术研究进展

超精密抛光是一种降低表面粗糙度,获得高表面质量和表面完整性的加工技术。蓝宝石作为典型的难加工硬脆材料,传统抛光方法存在表面会产生崩碎、划痕等损伤,表面质量难以得到保证以及加工效率低等问题。本文综述了应用于蓝宝石材料的磁流变抛光、水合抛光、化学机械抛光和激光抛光等技术的原理与特点及其研究现状,并分析了各抛光技术的优缺点;从表面质量、磨料与磨液、效率与成本等方面对各抛光技术进行比较;介绍了复合抛光技术在蓝宝石材料中的应用;最后重点展望了蓝宝石材料超精密抛光技术的下一步研究。     

用于蓝宝石材料加工的新型超精密抛光技术及复合抛光技术研究进展

超精密抛光是一种降低表面粗糙度,获得高表面质量和表面完整性的加工技术.蓝宝石作为典型的难加工硬脆材料,传统抛光方法存在表面会产生崩碎、划痕等损伤,表面质量难以得到保证以及加工效率低等问题.本文综述了应用于蓝宝石材料的磁流变抛光、水合抛光、化学机械抛光和激光抛光等技术的原理与特点及其研究现状,并分析了各抛光技术的优缺点;从表面质量、磨料与磨液、效率与成本等方面对各抛光技术进行比较;介绍了复合抛光技术在蓝宝石材料中的应用;最后重点展望了蓝宝石材料超精密抛光技术的下一步研究.     

Polishing of ceramic tiles

Grinding and polishing are important steps in the production of decorative vitreous ceramic tiles. Different combinations of finishing wheels and polishing wheels are tested to optimize their selection. The results show that the surface glossiness depends not only on the surface quality before machining, but also on the characteristics of the ceramic tiles as well as the performance of grinding and polishing wheels. The performance of the polishing wheel is the key for a good final surface quality. The surface glossiness after finishing must be above 20° in order to get higher polishing quality because finishing will limit the maximum surface glossiness by polishing. The optimized combination of grinding and polishing wheels for all the steps will achieve shorter machining times and better surface quality. No obvious relationships are found between the hardness of ceramic tiles and surface quality or the wear of grinding wheels; therefore, the hardness of the ceramic tile cannot be used for evaluating its machinability.     

Controllable hybrid side-polishing method (CHPM) for optical fibers by combination of polishing and etching

We introduce the controllable hybrid polishing method (CHPM), which is a combination of enhanced side-polishing and etching methods, leading to a more controllable and precise clad polishing process for optical fibers. The two key advantages of CHPM are enabling of real-time monitoring of the etching process with a resolution of ~100 nm and fabrication of a 34% smoother polished surface than that of traditional polishing methods. Bearing in mind that these two factors are very important for the fabrication of any polished fiber devices, such as plasmonic sensors, the CHPM should prove highly useful in related industrial and scientific applications.     

Surface characterization

The biocompatibility of commercially pure titanium and its alloys is closely related to their surface properties, with both the composition of the protecting oxide film and the surface topography playing an important role. Surfaces of commercially pure titanium and of the two alloys Ti–6Al–7Nb and Ti–6Al–4V (wt %) have been investigated following three different pretreatments: polishing, nitric acid passivation and pickling in nitric acid–hydrogen fluoride. Nitric acid treatment is found to substantially reduce the concentration of surface contaminants present after polishing. The natural 4–6 nm thick oxide layer on commercially pure titanium is composed of titanium oxide in different oxidation states (TiO2, Ti2O3 and TiO), while for the alloys, aluminium and niobium or vanadium are additionally present in oxidized form (Al2O3, Nb2O5 or V-oxides). The concentrations of the alloying elements at the surface are shown to be strongly dependent on the pretreatment process. While pickling increases the surface roughness of both commercially pure titanium and the alloys, different mechanisms appear to be involved. In the case of commercially pure titanium, the dissolution rate depends on grain orientation, whereas in the case of the two alloys, selective -phase dissolution and enrichment of the -phase appears to occur. © 1999 Kluwer Academic Publishers     

单晶硅镜面超光滑表面工艺技术研究

用古典的沥青盘抛光技术,通过对超光滑抛光时所使用磨料的选取、沥青抛光盘的软硬和 厚度的合理应用、抛光温度的控制等工艺参数的优化,以f220mm内的单晶硅进行了超光滑表面抛光工艺试验。试验结果,单晶硅表面粗糙度RMS值达0.37nm,平面面形误差PV小于l/15,且加工工艺技术稳定可靠。     

Optimization of Polishing Parameters with Taguchi Method for LBO Crystal in CMP

Chemical mechanical polishing(CMP)was used to polish Lithium triborate(LiB3O5 or LBO)crystal.Taguchi method was applied for optimization of the polishing parameters.Material removal rate(MRR)and surface roughness are considered as criteria for the optimization.The polishing pressure,the abrasive concentration and the table velocity are important parameters which influence MRR and surface roughness in CMP of LBO crystal.Experiment results indicate that for MRR the polishing pressure is the most significant p...     

Development of surface finish during the polishing of porcelain ceramic tiles

Polishing tests on a laboratory scale have been used to simulate and study the industrial polishing process for unglazed porcelain ceramic tiles. Tile surface quality was assessed in terms of roughness and optical gloss. Tests with a sequence of progressively smaller silicon carbide abrasive particles showed a general trend of decreasing roughness and increasing gloss during the process. The coarser abrasives (larger than 400 grit number) caused the major change in surface roughness, while the finer abrasives (smaller than 400 grit number) produced the major change in gloss. In these materials the maximum gloss achievable by polishing is limited by the porosity of the ceramic. The rate of material removal during polishing with a coarse abrasive obeyed an Archard-type wear law, being linearly proportional to applied load, although load had little effect on the surface roughness attained after different durations of polishing. In contrast, load had a significant effect on gloss, with higher loads leading to higher values of gloss. The development of both roughness and gloss with polishing time is well described by quantitative empirical models involving a simple exponential function. The same model for gloss evolution is also shown to apply to data reported from industrial-scale polishing experiments in previous work.     

Influence of Processing Techniques on the Surface Microstructure of V<Subscript>85</Subscript>Ni<Subscript>15</Subscript> Membrane Alloy

Vanadium-based alloys with a BCC structure are considered to be an alternative to palladium alloys for hydrogen purification. Since the performance of membranes is influenced by not only their bulk characteristics but also their surface condition, we have investigated the effect of different surface preparation techniques (abrasive grinding and polishing, electrolytic polishing, and ion etching) on the surface microstructure of V₈₅Ni₁₅ membrane alloy using X-ray photoelectron spectroscopy. After electrolytic polishing and ion etching, we observed an increase in the percentages of vanadium and nickel metals in the surface layer of the alloy in comparison with its state after abrasive polishing. Such changes are expected to be favorable for an increase in the rate of hydrogen dissociation and recombination on the surface of the membrane material, eventually improving hydrogen transport efficiency.     

哈氏合金电化学抛光工艺的研究

采用环保型抛光液对离子束辅助沉积技术路线用哈氏合金HastelloyC-276基带进行了电化学抛光,获得了典型的阳极极化曲线,并阐述了电化学抛光的机理.研究了影响电化学抛光的因素(电解液温度、抛光时间、抛光极距)对基带表面粗糙度的影响,优化工艺参数获得了表面粗糙度Rn＜5 nm(5μm×5μm)的高质量表面,满足后续生长过渡层对哈氏合金基带的要求.抛光液中的柠檬酸在50℃左右分解成络合剂,可迅速沉淀金属离子,提高表面的活性.     

无机材料超光滑表面的制备

随着光学、微电子、航天和激光技术的发展，在晶体或玻璃等无机材料上制备亚纳米级的超光滑无损伤表面已成为现代精密加工技术领域的重点研究课题。近年来，此项技术研究进展声速，不仅改进了传统的抛光技术，还出现了浮法抛光、离子束加工和弹性发射加工等新技术。系统介绍了超光滑表面的检测、制备技术及其发展，并讨论了抛光过程中的机械化学作用机理。     

复合抛光对 CVD金刚石薄膜表面光洁度的改进研究

采用激光抛光和热化学抛光相结合的方法，对通过热丝CVD方法生长的金刚石薄膜进行了复合抛光处理．并利用X射线衍射仪（XRD）、拉曼光谱仪（Raman）、扫描电子显微镜（SEM）和原子力显微镜（AFM）对金刚石薄膜进行了表征．结果表明，所合成的金刚石薄膜是高质量的多晶（111）取向膜；经复合抛光后，金刚石薄膜的结构没有因抛光而发生改变，金刚石薄膜的表面粗糙度明显降低，光洁度大幅度提高，表面粗糙度Ra在100nm左右，基本可以达到应用的要求．     

The Effect of Electrochemical Polishing Time on Surface Topography of Mild Steel

This paper investigated the variation of the altitude density function （ADF） and the autocorrelation function （ ACF） about the surface profile of mild steel during electrochemical polishing （ECP）. The results show that the variation features of ADF with polishing time are fiat-steep-fiat, and the variation features of A CF with polishing time are random-regular-random. There is a fine surface smoothness at the special period of ECP. Both the original surface and the full ECP surface show an obvious roughness.     

Effect of slurry composition on the chemical mechanical polishing of thin diamond films

Nanocrystalline diamond (NCD) thin films grown by chemical vapour deposition have an intrinsic surface roughness, which hinders the development and performance of the films’ various applications. Traditional methods of diamond polishing are not effective on NCD thin films. Films either shatter due to the combination of wafer bow and high mechanical pressures or produce uneven surfaces, which has led to the adaptation of the chemical mechanical polishing (CMP) technique for NCD films. This process is poorly understood and in need of optimisation. To compare the effect of slurry composition and pH upon polishing rates, a series of NCD thin films have been polished for three hours using a Logitech Ltd. Tribo CMP System in conjunction with a polyester/polyurethane polishing cloth and six different slurries. The reduction in surface roughness was measured hourly using an atomic force microscope. The final surface chemistry was examined using X-ray photoelectron spectroscopy and a scanning electron microscope. It was found that of all the various properties of the slurries, including pH and composition, the particle size was the determining factor for the polishing rate. The smaller particles polishing at a greater rate than the larger ones.     

Formation of porous niobium films by oblique angle deposition: Influence of substrate morphology

The present work demonstrates the formation of porous niobium films with separated columnar structures by oblique angle magnetron sputtering for capacitor application. The niobium films deposited on textured aluminium substrates, which had concave cell structures with the cell sizes ranging from 125 nm to 550 nm, consist of isolated columns of niobium with wider gaps between columns developing on the substrates with larger cell sizes. The surface areas of the deposited films, evaluated by the capacitance of the anodic films formed at several voltages, increased with an increase in the cell size of substrate. The surface area decreases with an increase in the formation potential of anodic films from 2 V to 10 V vs Ag/AgCl, because the gaps are filled with anodic oxide as a consequence of the large Pilling-Bedworth ratio of 2.6 for the Nb/Nb₂O₅ system. The reduction of the surface area is suppressed when the substrate with larger cell size is used, due to the formation of niobium columns with wider gaps, which are not filled with anodic oxide. The high surface area even at higher formation voltages of the anodic films is a requisite for capacitor application.     

Effect of the niobium pentoxide powder dispersity on the mechanical properties of niobate ferroelectric ceramics

Dispersity of the initial niobium pentoxide powder used in the synthesis of niobate ceramics significantly affects the mechanical properties of these ferroelectric materials. The best mechanical properties were observed in the samples of niobate ceramics characterized by a minimum deformation of the unit cells, corresponding to certain intervals of the specific surface of the initial niobium pentoxide powder. These results must be taken into account in the research, synthesis, and development of niobate ferroelectric ceramics for various applications.     

Li2O-A12O3-SiO2微晶玻璃超光滑表面纳米划痕产生机理及抑制实验研究

对Li2O-A12O3-SiO2微晶玻璃超光滑表面进行了纳米划痕实验,测得微晶玻璃超光滑表面弹性一塑性与塑性．脆性转变的临界载荷分别为3．906mN和29．78mN．通过对微晶玻璃超光滑表面划痕产生机理进行分析,得出在纳米尺度的抛光加工过程中,抛光颗粒的载荷越接近弹塑转变临界载荷,则样品表面产生的划痕越少,越易获得无划痕的超光滑表面．通过对比抛光工艺优化前后的实验结果,可以看出优化后的抛光工艺对超光滑表面划痕的抑制效果较明显,证实了上述研究结果的正确性．该研究结果对于Li2O-A12O3-SiO2微晶玻璃超光滑表面加工具有一定的指导意义．     

不锈钢表面处理:酸洗、钝化与抛光

介绍了近年来开发的部分不锈钢产品的酸洗、钝化及机械抛光、化学抛光、电化学抛光工艺,针对不同的不锈钢牌号及零件规格,给出了相应的表面处理配方及工艺方案。     

Effect of the Cd<Subscript>0.96</Subscript>Zn<Subscript>0.04</Subscript>Te substrate polishing procedure on Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Hg<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Te liquid phase epitaxy

This paper examines the effect of polishing procedure on the surface quality of Cd_0.96Zn_0.04Te substrates for Cd _x Hg_{1 − x} Te liquid phase epitaxy. Two polishing procedures are tested: stepwise polishing involving abrasive, chemomechanical, and chemical steps with the use of various abrasives, and abrasive-free polishing. The optimal procedure is chemomechanical polishing with no abrasives. The type of substrate surface can be identified using the Nakagawa etchant, which produces etch patterns in the form of triangles on the A(111) surface and circles on the B(111) surface.     

精细雾化抛光氮化硅陶瓷的抛光液配制参数优化

采用超声精细雾化施液抛光对氮化硅陶瓷基体进行抛光,研究了不同的pH值、磨料浓度以及氧化剂含量对氮化硅陶瓷基体抛光的材料去除率的影响,优化了pH值、磨料浓度及氧化剂含量,并与传统的化学机械抛光进行了对比。结果表明:当二氧化硅磨粒质量分数为5wt%,氧化剂含量为1wt%,pH值为8时,材料去除率MRR为108.24nm/min且表面粗糙度Ra为3.39nm。在相同的抛光参数下,传统化学机械抛光的材料去除率MRR为125nm/min,表面粗糙度Ra为2.13nm;精细雾化抛光的材料去除率及表面粗糙度与传统抛光接近,但精细雾化抛光所用抛光液用量仅为传统抛光所用抛光液用量的1/9。