陶瓷结合剂金刚石磨具(外文文献).pdf

International Journal of Refractory Metals accepted 1 November 2005 Abstract A glass matrix was chosen to bond diamond grits into vitriWed bond diamond grinding wheels The processing variables included the variation of volume percentages of pore forming polymer beads sintering atmosphere sintering temperature and sintering time Thermal mechanical analysis was carried out to identify the shrinking behavior of the composite during sintering showing that the shrinkage of the composite became signiWcant at temperatures higher than the glass transition temperature of the glass bonding matrix around 520 600 C Raman spectra were used to identify the inXuence of sintering atmosphere on the diamond grits Results indicated that air atmo sphere was required for clean burnout of the pore forming polymer beads while an inert atmosphere such as nitrogen was necessary for the high temperature sintering in order to avoid the oxidation and graphitization of the diamond grits In the range of the sintering tem perature and isothermal holding time investigated in this study sintering temperature had a greater inXuence on the wheel s grinding per formance than isothermal holding time The bond hardness and shrinkage percentage closely maintained linear relationships with the isothermal holding time at a sintering temperature of 700 C A highest grinding ratio was achieved when the diamond wheels were sin tered at 700 C for 120min 2005 Elsevier Ltd All rights reserved Keywords VitriWed bond Diamond grinding wheel Sintering Microstructure Grinding ratio 1 Introduction Diamond grinding wheels are a group of composite materials that are composed of diamond grits and a bond ing matrix The familiar bonding materials include metal resin and vitriWed glass 1 3 The strength of resin bond is lower than that of metal or vitriWed bond which accord ingly yields a shorter wheel life Resin bond diamond wheels are fabricated by hot pressing which yields a bond ing matrix without large pore causing deterioration in chip removal and heat dissipation Moreover due to its low grinding ratio resin bond grinding wheels need constant truing and dressing in the whole grinding process in order to maintain the accurate shape 4 Metal bond diamond grinding wheels have higher bonding strength between the diamond grits and the bonding matrix than that of resin bond wheels and consequently longer tool life The metal bonding matrix is usually composed of bronze and the dia mond bronze composite is formed by hot pressing There fore a structure with intentionally introduced pores can hardly be attained 5 6 which along with the high ductility of the metal matrix retards the exposure of new cutting edges when the diamond grits become dull during grinding process Severe friction between the metal bond and the workpiece is thus induced which accordingly raises the work piece temperature and reduces the grinding eYciency On the other hand vitriWed bond diamond grinding wheels also have higher bond strength than resin bond ones Nev ertheless the high elastic modulus and low fracture tough ness of the glass bonding materials facilitate a self dressing capability of wheels which can be further enhanced when large pores are intentionally introduced into the wheels 7 Corresponding author Tel 886 2 8662 5915 fax 886 2 8662 5919 E mail address khlin mail tnit edu tw K H Lin 26K H Lin et al International Journal of Refractory Metals 19 3 221 3 3 Ogawa S Okamoto T The eVect of vitriWed bond composition on wheel life Bull Jpn Soc Prec Eng 1986 20 4 264 71 4 Available from 5 Liao YS Luo SY EVect of matrix characteristics on diamond J Mater Sci 1993 28 1245 51 6 Liu XF Li YZ The microanalysis of the bonding condition between coated diamond and matrix Int J Refr Metals Hard Mater 2003 21 1 119 23 7 Tanaka T Esaki S Nishida K Nakajima T Ueno K Development and application of porous vitriWed bonded wheel with ultra Wne dia mond abrasives Key Eng Mater 257 258 2004 251 6 8 Kuroshima Y Kondo Y Okada S Development of vitriWed diamond grinding wheel for engineering ceramics J Ceram Soc Jpn 1985 93 9 587 9 9 Jackson MJ Barlow N Mills B The eVect of bond composition on the strength of partially bonded vitriWed ceramic abrasives J Mater Sci Lett 1994 13 1287 9 10 Wagner J Ramsteiner M Wild C Koidl P Resonant Raman scatter ing of amorphous carbon and polycrystalline diamond Wlms Phys Rev B 1989 40 3 1817 23 11 Peng SF Lin YY Lin KH Lin ST Reaction of diamond with a boro silicate glass In 2005 International conference on materials for advanced technologies Singapore July 3 8 O 4 PO63 12 Wang J Yan H Deng Y Li H Zhang Y Zhang F et al The compar ative study on diamond Wlm by near Weld Raman spectroscopy and micro Raman spectroscopy Solid State Commun 2000 115 173 7 Fig 9 Vari