添加剂对微晶玻璃化学机械抛光的影响

利用自制抛光液对微晶玻璃进行化学机械抛光,研究络合剂、氧化剂、润滑剂种类及添加量对微晶玻璃化学机械抛光材料去除速率和表面粗糙度的影响。结果表明:抛光液中加入质量分数0.2%的EDTA络合剂后,能大幅降低材料表面粗糙度;加入质量分数2%的过硫酸铵氧化剂后能得到较光滑的材料表面和较高的材料去除速率;加入质量分数为0.2%的丙三醇润滑剂后能降低材料表面粗糙度。将EDTA络合剂、过硫酸铵氧化剂丙、三醇润滑剂加入SiO_2抛光液中对微晶玻璃进行化学机械抛光,利用原子力显微镜观察抛光微晶玻璃抛光前后的表面形貌。结果表明,抛光后微晶玻璃表面极为平整,达到了0.12 nm的纳米级光滑表面,且材料去除速率达到72.8 nm/min。     

中等粒度纳米金刚石抛光陶瓷表面研究

研究了用各种不同粒度分布的纳米金刚石抛光CaTiO3陶瓷表面。讨论了纳米金刚石颗粒大小及其悬浮液的分散稳定性对磁头表面形貌的影响,评价了由该种材料抛光所形成的缺陷和表面质量。试验分析表明,用粒径越小、粒度分布越窄的纳米金刚石抛光时试样表面粗糙度越小,而粒径越大,即使分布窄,所得的试样表面粗糙度也越大。同时,即使纳米金刚石粒径较小,如果分散稳定性不好,也会在试样表面产生若干很深的划痕和凹坑,从而影响表面粗糙度。     

基于HHT变换的微晶玻璃超光滑表面抛光工艺技术研究

为了稳定地获得高质量的微晶玻璃超光滑表面,采用一种先进的超光滑表面抛光方法——定偏心浸液式抛光方法。首先分析了微晶玻璃的性能和微观结构,得出实现其超光滑表面抛光所必须的技术条件;然后,论述了浸液式超光滑表面抛光方法的基本原理及其抛光工艺过程。采用该方法稳定地获得了亚纳米量级粗糙度的超光滑表面,粗糙度达到Ra0.3nm;最后,采用HHT方法,通过粗糙度分布曲线到Hilbert谱的数学变换,得出主要抛光工艺参数与表面粗糙度之间的相互影响关系。结果表明,HHT用于超光滑表面的检测和评价,对实际抛光过程提出有效指导,有助于获得高质量的超光滑表面。     

纳米氧化硅在玻璃基片表面亚纳米级抛光中的应用

为满足先进电子产品对玻璃基片表面超光滑的要求,制备了一种纳米氧化硅抛光液,并研究了氧化硅粒子大小、抛光时间等参数对玻璃基片抛光后表面粗糙度、材料去除速率的影响。ZYGO形貌仪表明,采用纳米氧化硅抛光液,可以使玻璃表面粗糙度达到0.5 nm左右。AFM表明,抛光后的玻璃基片表面超光滑且无划痕等微观缺陷。     

国际领先的金刚石抛光液通过鉴定

天津市乾宇超硬科技有限公司经过多年潜心研究，根据不同用途配制了8种粒度（从2～6mm到0．75～1．50μm）的系列金刚石抛光液。它们既可用单晶金刚石制造，又可用多晶金刚石制造，并选择了最佳浓度以提高产品的性价比。该抛光液金刚石粒度公布精度极高，颗粒分布均匀。经测试用1μm粒度的金刚石抛光液抛光金属工件，表面粗糙度肋值可由80nm提高至0．91nm。用纳米金刚石抛光液对硬脆材料抛光，可使表面粗糙度达Ra0．1～0．3nm。     

基于HHT的微晶玻璃超光滑表面抛光

针对激光陀螺反射镜常用材料微晶玻璃的加工技术,介绍了一种较为成熟的超光滑表面加工方法-定偏心浸液式抛光.分析了微晶玻璃的性能和微观结构,得出实现其超光滑表面加工所必须的技术条件.系统论述了提出的超光滑表面抛光方法的基本原理及其抛光工艺过程.通过多次工艺实验,稳定地获得了埃量级的超光滑表面.最后,采用Hilbert-Huang变换(HHT)非线性平稳信号的时域分析法,通过超光滑表面粗糙度分布曲线到Hilbert谱的一系列数学变换,得出主要抛光工艺参数与表面粗糙度之间的影响关系,对实际加工工艺过程与抛光结果进行有效反馈和指导.基于HHT的超光滑表面抛光方法可以稳定地获得Ra优于0.35 nm的微晶玻璃超光滑表面,目前最好结果为Ra=0.3 nm.     

应用纳米级金刚石抛光亚纳米级光滑表面

用爆炸法合成的纳米级金刚石是一种新型纳米材料,其物理机械特性与普通亚微米级金刚石微粉有很大差别。我们使用这种材料配制的抛光液对YVO4 晶体进行了超精密抛光的初步实验,获得了具有较低表面粗糙度(< 1 nm )的表面,发现了纳米金刚石作为抛光材料的独特之处。本文描述了实验结果,分析了抛光表面,并总结了纳米金刚石粉的抛光特性,提出了关于抛光中的材料去除过程的见解     

抛光液pH值等对硬盘玻璃盘基片化学机械抛光的影响

随着硬盘存储密度的增大、转速的提高、磁头飞行高度的降低,对硬盘基板材料及基板表面质量提出了更高的要求。采用纳米SiO2作为抛光磨料,在不同抛光液条件下(pH值、表面活性剂、润滑剂等),对玻璃基片化学机械抛光去除速率和表面质量的变化规律进行了研究,并利用原子力显微镜(AFM)和光学显微镜观察了抛光表面的微观形貌。结果表明,玻璃基片去除速率在酸性、碱性条件下变化趋势相近,即随着pH值的升高,材料去除速率先增大后减小。加入一定量的表面活性剂和润滑剂使得去除速率有一定程度的下降,但是表面粗糙度明显降低,并且表面没有出现颗粒吸附现象。     

硬盘巨磁电阻磁头的超精密抛光工艺

硬盘巨磁电阻磁头的抛光可分为自由磨粒抛光和纳米研磨,在自由磨粒抛光中,精确控制载荷和金刚石磨粒的粒径,可以避免脆性去除实现延性去除。通过控制抛光过程中的抛光盘表面粗糙度、金刚石粒径大小及粒径分布和载荷等进行滚动磨粒和滑动磨粒比例的调控,获得较好的磁头表面质量和较高的材料去除率。在自由磨粒抛光阶段,先采用铅磨盘抛光,然后用锡磨盘抛光,以纳米研磨作为最后一道抛光工序对磁头表面进行研磨,获得了亚纳米级粗糙度的磁头表面。用两种工艺制作的纳米研磨盘进行加工,分别获得了0.37nm和0.8nm的磁头表面粗糙度,去除率分别为5.3 nm/min和3.9nm/min。     

聚晶金刚石复合片镜面加工工艺优化研究

针对聚晶金刚石复合片精加工后需达到镜面级表面的指标要求,基于正交试验法优化聚晶金刚石复合片精加工工艺参数,采用极差分析法处理试验数据,并绘制试验指标与各试验因素间的关系曲线图,得出了各因素对表面粗糙度的影响规律,并以此为基础优化工艺参数,进行聚晶金刚石复合片镜面加工工艺优化研究。研究表明:抛光盘转速和研抛时间对工件表面粗糙度影响较大,各因素对表面粗糙度的影响程度按从大到小的顺序依次为:抛光盘转速、研抛时间、研抛压力和抛光液磨料粒度。采用优化后的最优工艺参数组合进行加工试验,当研抛压力为90 kPa、抛光盘转速为1 200 r/min、抛光液磨料粒度为1μm、研抛时间为30 min时,得到了表面粗糙度Ra为0.019μm的质量表面,达到了聚晶金刚石复合片镜面加工(Ra0.02μm)的效果。     

立、卧式磁性复合流体抛光对比实验研究

针对磁性复合流体(MCF)抛光的两种抛光头,进行MCF抛光特性对比实验研究。开展了黄铜H26的平面抛光实验,调查立式和卧式抛光头分别对工件材料去除率、表面形貌与粗糙度以及MCF水分损耗等抛光特性的影响。实验结果表明,卧式MCF抛光能够较快地降低表面粗糙度,获得较高的材料去除率,MCF水分损失相对较快;立式MCF抛光能够在相对较长时间内获得稳定的材料去除率和表面粗糙度,MCF水分损失也较为平稳。     

Effects of particle size, polishing pad and contact pressure in free abrasive polishing

The objective of this research is to better understand the mechanisms of material removal in the free abrasive polishing process. Experiments were carried out to understand the effects of particle size, polishing pad and nominal contact pressure on the wear rate and surface roughness of the polished surface. A theoretical model was developed to predict the relationship between the polishing parameters and the wear rate for the case of hard abrasive particles sandwiched between a soft pad and a workpiece (softer than the abrasive particles). Experimental results and theoretical predictions indicate that the wear rate increases with an increase in particle size, hardness of polishing pad and nominal contact pressure, and with a decrease in elastic modulus of the polishing pad. Surface roughness increases with an increase in particle size and hardness of polishing pad, and nominal contact pressure has little effect on the roughness. A dimensionless parameter, wear index which combines all of the preceding parameters, was introduced to give a semi-quantitative prediction for the wear rate in free abrasive polishing. It is also suggested that when polishing hard material, in order to achieve a high materials removal rate and a smooth surface, it is preferable to use diamond as the polishing particles because of their high deformation resistance.     

Optimization of the chemical mechanical polishing process for optical silicon substrates

Chemical mechanical polishing (CMP) experiments are performed to study the effects of four key process factors on the flatness and surface finish of the polished optical silicon substrates and on the material removal rate (MRR). The experimental results and analyses reveal that the pad rotational speed and polish pressure have significant effects on the MRR, the interaction of the polish head rotational speed and slurry supply velocity and the interaction of the polish pressure and polish head rotational speed have significant effects on the flatness, and the pad rotational speed has a significant effect on the surface roughness R _t of the optical silicon substrates polished. The optimal combination of the four factors investigated is a polish pressure of 9,800 Pa, a pad rotational speed of 20 rpm, a polish head rotational speed of 20 rpm, and a slurry supply velocity of 100 ml/min. A confirmation CMP experiment has been carried out using the optimal process parameter setting obtained from the design of experiments analyses. The goal to attain optical silicon substrates with nanometric surface roughness and micrometric flatness by an optimized CMP process with a high MRR simultaneously so as to reduce the polishing time to only 15 min from over 8 h has been achieved.     

Modelling the effect of surface roughness factors in the machining of 2024Al/Al2O3 particle composites based on orthogonal arrays

This study presents an experimental investigation of the effects of cutting speed, size and volume fraction of particle on the surface roughness in turning of 2024Al alloy composites reinforced with Al₂O₃ particles. A plan of experiments, based on Taguchi method, was performed machining with different cutting speeds using coated carbide tools K10 and TP30. The objective was to establish a correlation between cutting speed, size and volume fraction of particle with the surface roughness in workpieces. These correlations were obtained by multiple linear regression. The analysis of variance was also employed to carry out the effects of these parameters on the surface roughness. The test results revealed that surface roughness increased with increasing the cutting speed and decreased with increasing the size and the volume fraction of particles for both cutting tools. The average surface roughness values of TP30 cutting tools were observed to be lower than those of K10 tools. For the average surface roughness values of TP30 tool, cutting speed was found to be the most effective factor while the volume fraction of particle was the most effective factor for those of K10 tool. A good agreement between the predicted and experimental surface roughness was observed within a reasonable limit.     

A novel method for micro-gap control in electrogenerated chemical polishing

In the electrogenerated chemical polishing (EGCP), material removal rate (MRR) is inversely proportional to the processing gap. To polish a workpiece with a large area, high and uniform MRR is necessary, which prefers a small and uniform processing gap. Based on the principle of the hydrostatic support, a novel micro-gap control method is proposed. The method uniformly controls the gap between the electrode and workpiece to a micro level over a large area. A relationship between the gap size and the inlet pressure is derived theoretically and verified experimentally. The proposed method is successfully applied to the polishing of a Cu surface with a diameter of 50 mm. Promising results are obtained that surface roughness and flatness are reduced from average roughness (Ra) 82 nm and peak-to-valley (PV) value 290 nm to Ra 4 nm and PV 120 nm, respectively.     

磨削抛光45钢的试验研究い

针对传统抛光方式的缺点,设计了一种磨液射流磨削抛光装置。利用这种装置对45钢试件进行表面磨削抛光,获得了高的表面质量,且加工表面无加工变质层。通过正交试验证明,在加工时间不变的前提下,喷射角度是影响去除量的主要因素,而喷嘴直径对表面粗糙度影响较大,同时得出加工影响因素的主次关系及其较优水平组合。     

基于喷射抛光实验研究结果的异形抛光实验台设计

介绍了标准的液体喷射抛光实验,提出了近壁面附近固液两相流中的颗粒作用导致的流体摩擦剪切去除材料的机制假设,然后通过实验研究了抛光时间、样品表面初始粗糙度、喷头形状、喷射距离、喷射压力和pH值对抛光结果的影响。结果表明,抛光结果随时间趋于稳定并与初始粗糙度无关,圆形喷头比扇形喷头抛光效率高,喷射距离和压力影响一致,pH值越低影响越大。最后基于理论假设和实验结果设计了一个可以用于精密光学制造中异形表面抛光的实验装置。     

Surface roughness and material removal rate of lapping process on ceramics

Lapping is a widely used surface finishing process for ceramics. An experimental investigation is conducted into the lapping of alumina, Ni−Zn ferrite and sodium silicate glass using SiC abrasive to study the effect of process parameters, such as abrasive particle size, lapping pressure, and abrasive concentration, on the surface roughness and material removal rate during lapping. A simple model is developed based on the indentation fracture and abrasive particle distribution in the slurry to explain various aspects of the lapping process. The model provides predictions for the surface roughness,R _a andR _t , on the machined surface and rough estimation for the material removal rate during lapping. Comparison of the predictions with the experimental measurements reveals same order of magnitude accuracy.