1、 毕业设计外文资料翻译 题 目 金属结合剂金刚石砂轮的精密 内圆磨削 学 院 机械工程学院 专 业 机械工程及自动化 班 级 机升 0901 学 生 学 号 指导教师 二一 一 年 四 月 十 日 济南大学毕业设计外文资料翻译 - 1 - Journal of Materials Processing Technology, 2000, 105:80-86. Precision internal grinding with a metal-bonded diamond grinding wheel Jun Qian, Wei Li, Hitoshi Ohmorib Nanjing Univer
2、sity of Aeronautics and Astronautics Abstract A metal-bonded grinding wheel, compared with conventional grinding wheels, offers the advantage of high hardness, high holding ability and finer usable abrasive grit mesh sizes. The truing and dressing of a metal-bonded diamond (MBD) wheel, in practice,
3、are very difficult. To grind small-diameter internal cylindrical surface with MBD-wheels, an interval electrolytic in-process dressing (ELID) method was utilized. Experiments were carried out on an ordinary cylindrical grinding machine with an attached internal grinding set-up, and straight type gri
4、nding wheels of different grit sizes were used. The grinding wheels were trued, using the electrical discharge method, and the effects of electrode shapes, grinding parameters, and grit sizes were evaluated experimentally. Mirror surface grinding of different materials was carried out with a #4000 C
5、IB-D wheel, incorporated with this interval ELID (ELID II) method. The experimental results are reported # 2000 Elsevier Science S.A. All rights reserved. Keywords: Cylindrical grinding； Metal-bonded grinding wheel； Dressing； Electrolytic in-process dressing； Precision grinding 1. Introduction Along
6、 with the technological advancement of ultra-precision grinding, applications and requirements for precision cylindrical surfaces have increased significantly in the recent years 1. As a principal processing method for an internal surface, cylindrical grinding has been commonly utilized as a final o
7、peration in the production of precision components. Since grinding is usually the most costly of all manufacturing processes, considerable attempts have been focused on the analysis and optimization of the grinding process to minimize machining time 2-6, and on various compensatory control strategie
8、s to improve workpiece quality 7-10 in the cylindrical grinding. However, few researches on mirror-surface internal grinding have been reported 5,6,11, probably due to the limitation of abrasive grit size applicable to non-metallic bond grinding wheels 5,7,8,10. Research on high efficiency grinding
9、of advanced materials, by utilizing high-rigidity grinding machines and tough metal-bonded superabrasive wheels, has led to the successful development of cast iron bonded diamond (CIB-D) grinding wheels 12. These wheels are manufactured by mixing diamond grits, cast iron powder or fiber, and a small
10、 amount of carbonyl iron powder. The wheels are compacted 济南大学毕业设计外文资料翻译 - 2 - to a desired form under high pressure and then sintered in an atmosphere of ammonia. These wheels are not suitable for continuous grinding for a long period of time for the following reasons: (1) As tougher metal-bonded w
11、heels exhibit poor dressing ability, it is difficult to achieve efficient and stable dressing simultaneously. (2) Higher rate of material removal in the grinding promotes wear of the abrasive grains, therefore, more frequent redressing of the grinding wheel will be required by stopping the grinding
12、process. (3) While machining metals such as steel, wheel loading (embedding of swarf) occurs, making effective dressing of metallic bond wheel difficult in practice. Although a diamond slab incorporated with an abrasive jet sharpening method is able to dress a bronze-bonded wheel to the same topogra
13、phy as an electroplated wheel 12, complex equipment must be added inevitably which cause working-environment problem. Dressing by electrical discharge is a good method, but it is difficult to conduct on-line dressing, and dressing stripes appear on the wheel periphery when a pair of parallel electro
14、des is used 13,14. Electrolytic in-process dressing (ELID) has so far served as the most successful dressing method for metal-bonded wheels. It has been devised and applied successfully in precision surface grinding 15-17. However, its application to internal grinding has not been well investigated；
15、 especially when the internal diameter of the workpiece is just slightly larger than that of the grinding wheel, it is very difficult or even impossible to fix a dressing electrode mounted parallel to the wheel surface as in ordinary ELID grinding 15. A novel method to carry out ELID grinding of int
16、ernal cylindrical surfaces on an ordinary grinding tool is presented in this paper. The principle and process of this method, namely interval ELID (ELID II) grinding, is also discussed. Applying ELID II grinding to an ordinary grinding machine, some preliminary experiments have been carried out. Two
17、 types of dressing electrodes were used and their dressing effects were investigated. With this technology, four specimens of alumina ceramic, hardened steels SKH51 and SKD11 and bearing steel, were ground to mirror finish. The results of this research are presented in the following sections. 2. Pri
18、nciple of interval ELID grinding The interval dressing of an abrasive grinding wheel itself is not a new technology. In fact, using the common mechanical dressing methods, the wheel is usually dressed at intervals. The grinding process is stopped to dress the wheel after grinding one workpiece or se
19、veral work pieces. The tool life limit can be chatter vibration, surface roughness and burning marks, etc. 2. However, with the ELID II method, the wheel is dressed at intervals and the abrasives remain protruding, enabling the grinding process to go on without any interruption and consequently real
20、izing high efficiency grinding. The interval ELID system is essentially composed of thefollowing elements: (i) a metal-bonded grinding wheel, (ii)an ELID power source, (iii) electrolytic coolant, and (iv) a pipe dressing electrode. The most important feature of this process is that no special machine is required, and in fact the
