Advances in Abrasive Technology IX

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Authors: T. Sato, H. Yamaguchi, Takeo Shinmura, T. Okazaki
Abstract: This research studied the internal magnetic field assisted finishing with MRF (Magneto-rheological Fluid)-based slurry for copper tubes.MRF-based slurry that included diamond abrasives was applied to the internal magnetic field assisted finishing for copper tubes and the finishing characteristics were studied. The results showed that the exciting current and the abrasive size changed the finishing characteristics of MRF-based slurry. This finishing process creates a smooth mirror finished surface with few directional cutting marks on the surface of the copper tube.
Authors: Shao Hui Yin, Hitoshi Ohmori, Wei Min Lin, Yoshihiro Uehara
Authors: Hideki Fujita, Takeo Shinmura, H. Yamaguchi
Abstract: In the magnetic-field-assisted finishing, grinding powder mixed with iron powder is placed inside a part and vibration is applied to the part under magnetic field. Effects of the process on deburring of step-wise holes and internal roughness of brass square pipes were examined. Rotation was given to the pipes with step-wise holes, while the magnetic poles were vibrated. Axial vibration was given to the square pipes, while the magnetic poles were fixed. Burr formed by drilling at internal edges was effectively removed by the process. Inside roughness of the square pipe was successfully finished to 0.023 μm Ra.
Authors: Wen Jun Zhou, Yasuhiro Tani
Abstract: A new concept of finishing technology, Multi-Body Finishing (MBF), is proposed to broaden the concept of Polymer Particles Assisted Polishing (POPAP, named also as 4-body finishing). In this paper, a new 4-body finishing technology is developed, in which paste dispersion medium is used and fine polymer particles are introduced as the 4th body to extinguish the microscratches and improve the dispersion stability of the polishing paste. It is verified that both high removal rate and high dispersion stability, compared to the conventional paste, can be obtained by using the new paste in which the low viscosity base agent is used and the media particles considerably finer than the abrasives are added.
Authors: Wei Min Lin, Hitoshi Ohmori, T. Suzuki, Yoshihiro Uehara, Y. Watanabe, Shinya MORITA
Abstract: A new CAD system, which is called Volume-CAD (VCAD) have been developed. We carried out research and development of VCAD fabrication process based on VCAD/CAM precision control. In this study, a developed V-CAM had been used for a polishing fundamental experiment of a free form surface. The relationship between NC resolution and form accuracy of polished surface are discussed.
Authors: Koichi Kitajima, Akihiro Yamamoto, Moriyasu Izawa
Abstract: The speed-up of the disc rotation in dry centrifugal barrel finishing is done and its influence on finishing characteristics is experimentally examined. The workpiece is a sliced cold rolled bar of plain carbon steel (S45C in JIS, HB221). It is 32mm in diameter and finished to10mm in thickness by belt grinding. The equilateral triangular prism nylon media (1010mm, A#320) is used at 20vol% in media charging ratio. The disc rotation speed is increased up to 500min-1. By speeding up the disc rotation, the finishing speed improves, but the total efficiency decreases.
Authors: Gui Wen Kang, Fei Hu Zhang
Abstract: Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. The finishing process can be easily controlled by a computer. Material removal model in MRF is established. According to Preston equation in optical machining, mathematic model of material removal rate in MRF rotating at fixed rate is established through hydrodynamic analysis of the MR fluid flow in the polishing zone. The validity of the model is examined by the experimental results.
Authors: Shinya Suzuki, Nobuhito Yoshihara, Ji Wang Yan, Tsunemoto Kuriyagawa
Abstract: Plane honing machining of aluminum nitride (AlN) was investigated in this study. AlN has advantageous thermal and dielectric characteristics and is in great demand as a semiconductor mounting board or packaging parts material. However, as AlN is a sintered material, the AlN grains readily detach during machining making it difficult to obtain fine surface roughness at high efficiency. In previous studies, we have developed a new plane honing method that makes it possible to grind hard and brittle materials. In this paper, plane honing experiments of AlN were carried out using a resinoid or vitrified bond wheel. Fine surface roughness could be obtained using the resinoid bond wheel but there was low-machining efficiency due to burying and detachment of abrasives. The vitrified bond wheel, however, enabled high efficiency grinding but resulted in traces of detached AlN grains forming at the machined surface. Highly efficient mirror grinding of AlN could be achieved by using a vitrified bond wheel for semi-finishing and a resinoid bond wheel for finishing.
Authors: Gui Bing Pang, Wen Ji Xu, Xu Yue Wang, A.D.Y. Xie, H.Y. Li, H. Wang
Abstract: By analysing the change of the anodic surface topography in Electrochemical Abrasive Lapping (ECAL), the influence of the lapping action and the electrochemical action on the anodic smoothening velocity is studied. In electrochemical finishing, the micro-peaks on the anodic surface could be smoothened quickly by electrochemical action and the surface topography presents the profile wave, but in ECAL, the profile wave after electrochemical action could be divided into micro-peaks renewedly by lapping action and the alternation of electrochemical action and lapping action makes the surface topography before electrochemical action present profile micro-peaks, which will increase the anodic smoothening velocity. The influence of machining parameters, such as abrasive grain sizes, tool’s pressure, abrasive content, frictional velocity and current density etc, on the anodic smoothening velocity is discussed in detailed.
Authors: Y.J. Bai, Lian Hong Zhang, Cheng Zu Ren
Abstract: As a special kind of grinding, honing is a typical low speed precision machining process, which is of low grinding speed, little grinding heat and little thermal-residual deformation of workpiece, suitable for precision machining of holes in the precision couples of internal-combustion engine. Experimental investigation on effects of process parameters on honing efficiency of small holes was put forward in this paper to obtain economical machining efficiency. Circumferential speed, reciprocate speed and working pressure of honing stone are the key factors which affect the machining efficiency and quality of honing. Taking it as a case study the honing of the small middle hole of the valve seat of balancing valve couples of internal combustion engines, honing experiments were carried out in this paper to investigate the relationships of material removing rate in rough honing versus circumferential speed, reciprocate speed and working pressure in honing of small holes. The results show that in honing of small holes the material removal rate in rough honing increases with circumferential speed, reciprocate speed and reticulate cross-angle increasing but decreases when the two speeds exceed certain critical values, and the surface quality in finishing honing is improved by increasing circumferential speed.

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