Geometrical transcription of diamond electroplated tool in ultrasonic vibration assisted grinding of steel Mohd Fauzi Ismail a,n , Kazuhisa Yanagi b , Hiromi Isobe b a Fakulti Kejuruteraan Mekanikal, Universiti Teknologi Mara (UiTM), Shah Alam, Selangor 40450, Malaysia b Department of Mechanical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan article info Article history: Received 26 July 2011 Received in revised form 10 June 2012 Accepted 11 June 2012 Available online 28 June 2012 Keywords: Reference datum Surface topography Tool–work interaction Reversal method Ultrasonic vibration assisted grinding Diamond electroplated tool abstract Application of diamond electroplated tool (DET) to ultrasonic vibration assisted grinding (UVAG) of steel surface for mirror finish has been introduced, but the effect of DET working surface topography to the work roughness has not been clarified. The objectives of this study are to parameterize the DET based on the quantity and distribution of the active grains, and then to make clear how these grains protrusion parameters are related to UVAG performance (i.e., work roughness). In this paper, work roughness is used for the process assessment using characterization condition selected on the basis of the machining condition with white light interferometer as the measuring instrument. Higher magnification measurement on the work surface is performed, revealing the existence of ultrasonic vibration marks with unique constant wavelength for each sample which then is used for the estimation of active grain position. Meanwhile, in order to enable identification of the active grain based on the grain height, the entire DET working surface topography is measured in a single measurement and reversal method based procedure is used to extract the reference datum. The active grain identified from the DET working surface topography has a position similar to the one estimated from the work surface topography indicated the appropriateness of both methods. Simulation and experiment result showed the optimum position of the active grain for smoother work roughness. Furthermore, the multiple active grains with similar locus radius are observed to contribute to less roughness. The information gained in this study can improve the controllability of the UVAG. & 2012 Elsevier Ltd. All rights reserved. 1. Introduction An application of diamond electroplated tool (DET) in ultra- sonic vibration assisted grinding (UVAG) for mirror finish of mould steel was proposed [1]. The UVAG system was built using an NC milling machine with ultrasonic vibration source incorpo- rated in the main spindle to add the ultrasonic vibration to the rotating tool. The DET was made of super-hard alloy cylinder and the tool working surface is the flat end surface covered with sample 50/120 diamond grains by means of electroplating. In another report [2] the necessity of truncating the sharply pro- truded grain tips as a condition to obtain better surface finish was clarified, but the optimum truncation condition or method is unclear. Despite using the same 2 mm diameter tool, the reports [1–5] showed different machining condition (i.e., the spindle speed); from 4000 rpm to 2000 rpm or lower and depth of cut; from no clear effect to the smaller the better, in relation to works surface roughness. The changes indicate certain instability of the UVAG system while the most uncertain element of the grinding system is the tool–work interaction between the DET working surface and ground surface during grinding, and the analysis on the geometrical properties of the DET working surface topography is necessary to clarify the matter. The analysis of tool–work interaction requires information about the tool working surface topography [6] but characteriza- tion based on small sampled area only provides statistical characterization. The ground surface profile from the UVAG with DET was analyzed [5] and the possibility that only a small number of grains, probably one, are active during the grinding process was highlighted, but it is not yet known how the 3D grain protrusion parameters were related to the ground surface. Hence, the necessity to measure the whole DET working surface in a lump was proposed; the imperfection of the characterization when using least square reference datum was also highlighted [9]. Datum in dimensional metrology is defined as a theoretically exact plane, point or axis from which a dimension is measured [7]. In surface topography characterization, the reference datum is a base to which parameters are referred, or a reference to serve for the qualitative evaluation of the roughness of the surface. Reference datum in surface topography assessment can be separated into two Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/ijmactool International Journal of Machine Tools & Manufacture 0890-6955/$ - see front matter & 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijmachtools.2012.06.003 n Corresponding author. Tel.: þ60 13 397 6678; fax: þ60 4382 2853. E-mail address: kashu98@yahoo.com (M.F. Ismail). International Journal of Machine Tools & Manufacture 62 (2012) 24–31