玻璃制品孔加工工艺技术

在电镀金刚石工具端部开槽，可获得小的玻璃崩边直径和高的材料去除率。采用水冷却液的玻璃制品孔的加工质量最好，加工效率最高。在玻璃加工质量允许的条件下，玻璃制品孔加工宜选择高的切削速度、适当的外加载荷。     

光学玻璃金刚石加工机理初探

以金刚石为磨料的研磨和抛光工具在光学玻璃的加工中得到越来越广泛地应用,它不仅提高了加工效率而且改变了整个工艺方法。了解和研究金刚石工具对玻璃的作用机理已成为提高这种加工方法的质量和效率的重要课题。金刚石加工玻璃的机理涉及到很多有关玻璃、冷却液、金刚石工具和机床等方面的参数。由于这些参数的影响和参数之间的相互作用使加工机理变得非常复杂。本文从三个主要方面来说明对加工机理研究的现有成果。     

玻璃磨削参数对电镀金刚石工具磨削性能的影响

通过制备的电镀金刚石工具进行了玻璃磨边的正交试验 ,以工具磨削比作为考核指标 ,研究了玻璃加工中电镀金刚石工具磨损与磨削参数之间的关系 ,并确定了适宜的磨削参数     

珩齿加工中电镀金刚石工具的磨损

阐述了用电镀金刚石工具对淬硬后的齿轮进行珩齿的过程中,电镀金刚石工具的逐渐磨损对加工零件质量的影响。     

永磁材料套孔加工轴向进给力经验公式的建立

钕－铁－硼永磁材料的性能优于所有传统永磁体材料，它可使仪器仪表电子设备的元器件微型化，具有广阔的发展前景。钕－铁－硼永磁材料比较昂贵，为节约原材料，加工时应尽可能减小去除量，尤其是进行孔加工时，应采用套孔加工，芯柱可留作他用。用套料刀具在实心材料上环形切割称为套孔加工，套孔与钻孔相比不仅能减少轴向载荷，提高生产效率，而且能减少材料的损耗。用金刚石工具加工钕－铁－硼永磁材料是一种十分有效的加工方法。刀具结构如图所示。刀头上电镀金刚石并开有４个槽，在套孔时整个刀具的端面都参与切削，轴向抗力与工具的轴…     

用电镀珩具(铰刀)进行深孔精细加工

介绍了电镀珩具的制作方法及人造金刚石和立方氮化硼磨粒在电镀珩具上的应用。详述了该工具在长径比75以上的深孔加工中珩具的结构、加工工艺及切削参数。     

玻璃加工用电镀金刚石工具结合剂研究

通过不同结合剂的组织和性能研究,确定了适宜光学玻璃加工用电镀金刚石工具结合剂的类型以及制备电镀金刚石工具的最佳工艺条件。研究表明:试验采用的电镀金刚石工具制备工艺能保证工具在使用过程中具有良好的综合性能和较好的加工效果。     

电沉积金刚石钻头的研制

本文介绍采用Ni-Co合金电镀液，通过复合电镀方法在麻花钻头表面沉积一层或多层金刚石磨料，对电镀过程中各主要工艺参数的影响进行了试验研究，确定了电镀最佳工艺参数。试验结果表明，所获得的金刚石钻头可以用于玻璃、铁氧体、玛瑙、石材、陶瓷等硬脆性材料的钻削加工。本文对加工机理作了初步分析。     

电镀金刚石磨具电解法修锐工艺研究

本文介绍了电解法修锐电镀金刚石磨具的装置和工艺,分析了该法用于修复玻璃磨削用电镀金刚石砂轮的效果,讨论了影响修锐效果的工艺因素。研究结果表明,电解法修锐电镀金刚石磨具是适宜的,可大幅度提高磨削效率,使电镀金刚石磨具得到充分利用,有显著的经济效益。     

钎焊金刚石刀具钻削新型复合板试验

为解决新型“三明治”复合层板“凯芙拉复合材料-特种陶瓷-铝合金”孔加工的难题，文中尝试在Z5125立式钻床上采用电镀金刚石套料钻和最新研制的钎焊金刚石套料钻钻削通孔。试验结果表明：电镀金刚石套料钻仅钻削1／2个孔，金刚石磨料就完全脱落；钎焊金刚石套料钻连续钻削10个孔，切削部位无明显变化，加工效率高且孔表面光滑平整，完全满足技术要求，为新型复合材料层板“凯芙拉复合材料-特种陶瓷-铝合金”孔加工寻到了一条方便、经济、有效的新途径。     

钎焊套料钻钻削碳纤维增强复合材料层合板出口撕裂缺陷的成因分析

针对碳纤维增强复合材料钻孔时钻头寿命短、易产生加工缺陷等问题,将钎焊金刚石套料钻应用于碳纤维增强复合材料的钻削加工中。为更好地说明钎焊金刚石套料钻的加工性能,选取了复合材料钻削中常用的金刚石涂层麻花钻进行比较,并选择了实际加工中严重影响加工质量的出口撕裂缺陷进行成因分析。通过检测与分析出口处加工质量,得到以下结论：对于不同结构形式的钻头,仅依靠轴向力及扭矩并不能判断是否产生撕裂缺陷;在相同工艺参数下,钎焊金刚石套料钻的轴向力及扭矩均小于金刚石涂层麻花钻的轴向力及扭矩,使用钎焊金刚石套料钻更有利于减少撕裂缺陷,提高加工效率。     

Experimental investigation of surface and geometrical characteristics of rotary ultrasonic drilling of soda glass

Edge-chipping, surface roughness and dimensional accuracy are crucial quality aspects of drilled holes in hard-to-cut material such as glass, ceramics and carbon fiber reinforced plastics. In this article, an experimental study was conducted to investigate the quality measures of holes produced by rotary ultrasonic drilling (RUD) and conventional drilling. Edge-chipping width at tool exit side, the surface roughness (Ra and Rz), out-of-roundness, cylindricity error and hole conicity were the main responses when drilling soda glass using diamond abrasive tools and a cutting fluid. Statistically designed experiments were carried out for rotary ultrasonic and conventional drilling (CD) at two levels of tool feed rate (0.6 and 6?mm/min), spindle speed (3,000 and 8,000?rpm) and tool particles-concentration. Analysis of variance was used to define the significant factors and their interactions and build models for predicting the responses. The results showed that reducing the chipping, surface roughness and roundness error. The normal tool concentration showed a substantial effect in improving the surface quality and reducing the hole-geometrical errors.     

Experimental study on trepanning drilling of the ceramic composite armor using a sintering diamond tool

Laminated ceramic composite armors made of engineering ceramics, fiber-enforced composite, and lightweight alloy are expected to be used widely in armor protection area. However, secondary machining is still a problem for the distinct properties of composing materials, and up to now, few reports can be found out about machining technology. In this work, an experimental study on drilling a typical laminated ceramic composite armor by using a special sintering diamond thinwall trepanning tool has been carried out deeply. To improve the machining efficiency, process parameters including the spindle speed and the axial force have been optimized through drilling experiments. Moreover, the three phases of the whole drilling process of the typical ceramic composite armor is proposed, and the machining mechanism and chip forms in each phase have been analyzed. Also, diamond tool skidding phenomena whether at hole exit or during drilling middle engineering ceramics have been explored, and the skidding mechanisms are presented. In addition, the surface quality of a hole wall machined has been studied, and an advisable measure is given. Results achieved in this paper can provide a technical base for diamond trepanning tool drilling similar laminated ceramic composite armors.     

钎焊金刚石薄壁钻加工工程陶瓷的试验研究

通过用钎焊金刚石薄壁钻加工Al2O3工程陶瓷的钻削试验,测量和分析了在不同加工参数下钻削轴向力和扭矩的变化,并与电镀钻头的加工性能进行了对比。结果表明,用钎焊金刚石薄壁钻加工工程陶瓷材料的设想可行,与电镀钻头相比,钎焊钻头钻削过程更稳定,加工质量更好,尤其在高转速、大进给加工条件下具有明显优势。     

Comparative analysis of chipping mechanics of float glass during rotary ultrasonic drilling and conventional drilling: For multi-shaped tools

Float glass has immense applications such as sensor glass, micro-processor glass and decorative glass; because of its exceptional wear resistance, chemical and thermal characteristics. Nevertheless, researchers are still bearing decisive issues, which affect its application. These issues are profile inaccuracy and chipping because of its poor machining characteristics and hence high precision machining. The objective of the present study is to condemn the chipping related hindrances while using multi-shaped diamond abrasive tools to create blind holes. The tools, which applied, are named as hollow abrasive tool, pinpointed conical tool, flat cylindrical tools and concave circular tool. The experimental trials were performed by rotary ultrasonic drilling (RUD) and CNC conventional drilling (CD). The actual industrial conditions and parameters were considered throughout the experimentation. Physics behind the formation of chipping on hole periphery by RUD and CD are revealed. In addition, individual mechanisms of multi-shape tools with respect to chipping are analyzed. The results show that RUD process has attained the smallest measurement of chip radial distance as compared to CD for all types of tool. Finally, the concave circular tool is found as the best tool particularly to get least chip radial distance during drilling i.e. 0.1145?mm.     

Experimental evaluation of polycrystalline diamond tool geometries while drilling carbon fiber-reinforced plastics

Polycrystalline diamond (PCD) drills are commonly employed in carbon fiber-reinforced plastic (CFRP) drilling to satisfy hole quality conditions with an acceptable tool life and productivity. Despite their common use in industry, only a small number of studies have been reported on drilling CFRPs with PCD drills. In this study, drilling performances of three different PCD drill designs are investigated experimentally using thrust force, torque, and hole exit quality measurements. Results show that work material properties, drilling conditions, and drill design should all be considered together during the selection of process parameters, and the relationships among these factors are quite complex.     

电沉积金刚石钻削工具结构及参数优化

为提高脆硬材料的加工效率以及工具的使用寿命 ,对电沉积金刚石钻削工具结构进行了改进 ,优化了其结构参数 ,提出了采用开牙槽的套筒式结构作为基体的电沉积金刚石钻削工具。采用该类工具进行脆硬材料加工 ,可明显提高加工效率和使用寿命     

Improvement in tool life of electroplated diamond tools by Ni-based carbon nanotube composite coatings

Ni-based CNT composite (Ni-CNT) coatings were applied for improving the grain bonding strength of electroplated diamond tools. Further, since it is extremely important for the coatings to have good surface roughness for applications to micro-electroplated diamond tools, ultrasonic-vibration stirring was employed for improving the surface roughness of the coatings. The effects of the amount of CNTs in the plating bath on the hardness and grain bonding strength of Ni-CNT coatings were evaluated. Finally, we evaluated the tool life of microelectroplated diamond tools comprising Ni-CNT coatings as the topcoat layers by conducting experiments involving side machining and hole-drilling. The Vickers hardness of Ni-CNT coatings electroplated in a bath that contained more than 1-g/l CNTs exceeded 500 HV. The grain bonding strength can be improved by codepositing CNTs in Ni coatings and was almost 1.3 times in our estimations. In the case of the side machining of glass plates, electroplated diamond tools composed of the Ni-CNT coatings had a tool life approximately eight times longer than that of normal tools. Moreover, micro electroplated diamond tools also had a longer tool life for drilling holes in fused quartz glass. This represents the first experimental verification of the efficacy of Ni-CNT coatings in improving the grain bonding strength. In this manner, we have demonstrated that Ni-CNT coatings are extremely effective for improving the grain bonding strength of electroplated diamond tools.     

Tool wear and its effect on surface roughness in diamond cutting of glass soda-lime

For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest on wear phenomenon describing simply without analyzing the genesis of wear phenomenon and interpreting the formation process of tool wear in mechanics. For in depth understanding of the tool wear and its effect on surface roughness in diamond cutting of glass, experiments of diamond turning with cutting distance increasing gradually are carried out on soda-lime glass. The wear morphology of rake face and flank face, the corresponding surface features of workpiece and the surface roughness, and the material compositions of flank wear area are detected. Experimental results indicate that the flank wear is predominant in diamond cutting glass and the flank wear land is characterized by micro-grooves, some smooth crater on the rake face is also seen. The surface roughness begins to increase rapidly, when the cutting mode changes from ductile to brittle for the aggravation of tool wear with the cutting distance over 150 m. The main mechanisms of inducing tool wear in diamond cutting of glass are diffusion, mechanical friction, thermo-chemical action and abrasive wear. The proposed research makes analysis and research from wear mechanism on the tool wear and its effect on surface roughness in diamond cutting of glass, and provides theoretical basis for minimizing the tool wear in diamond cutting brittle materials, such as optical glass.     

Chipping minimization in drilling ceramic materials with rotary ultrasonic machining

Ultrasonic machining (USM) has been considered as a new cutting technology that does not rely on the conductance of the workpiece. USM presents no heating or electrochemical effects, with low surface damage and small residual stresses on workpiece material, such as glass, ceramics, and others; therefore, it is used to drill microholes in brittle materials. However, this process is very slow and tool wear dependent, so the entire process has low efficiency. Therefore, to increase microhole drilling productivity or hole quality, rotary ultrasonic machining (RUM) is considered as a strong alternative to USM. RUM, which presents ultrasonic axial vibration with tool rotation, is an effective solution for improving cutting speed, precision, tool wear, and other machining responses beyond those of the USM. This study aims to reduce the microchipping or cracking at the exit of the hole, which inevitably occurs when brittle materials are drilled, with consideration of tool wear. To this end, response surface analysis and desirability functions are used for experimental optimization. The experimental results showed that the proposed RUM scheme is suitable for microhole drilling.