| Modern grinding technology is trending into high speed, high efficiency, high precision, high automation and low cost. More and more new materials are invented and used, especially steel materials widely used in the fields of aircraft, automobile, machine, bearing and mould need efficiently grinding with high precision. Cubic boron nitride (CBN) has high hardness and good thermal stability and it is chemically inactive with carbon and alloy steels and resin-bonded superabrasive wheel is well known as its great tensile strength, low grinding forces and temperature, some elastic behavior and self-sharpening, thus resin-bonded CBN wheel can grind hardened alloy steel with high efficiency and accuracy. But resin matrix can't resist to high temperature shock and great power wear and the binding strength between resin and abrasive grains is weak which lead to the service life span of resin-bonded grinding wheel universally not being long. Difficultilly dressing and truing is another drawback of resin-bonded grinding wheel. This paper is aim to manufacture advanced machining tools by means of optimizing resin thermosetting process and formulation design and improving the binding strength of abrasive grains and resin matrix based on composite materials preparing principles and grinding process theory.Usually used as binder of resin-bonded superabrasive grinding wheels are phonelic resin and polyimide resin. This paper first analyzes principles of both synthesis methods and thermalsetting and structure characteristics and determines appropriate heat cure process, then compares their processing, thermal and mechanical properties. The structure characteristics of pre-curing and after-curing resin can be judged by FTIR and XRD diagram.Through observing on the change of DSC and TG and jelling-time and mechanical properties of both resins, the phonelic resin thermal-curing process is determined that holding time is 140oC×2h, 165oC×2h, 180oC×2h, gradually heating-up and free cooling-down and the polyimide resin thermal-curing process is that holding time is 120oC×1h, 180oC×2h, 220oC×2h, 235oC×2h,fast heating-up and free cooling-down.Comparison of the resin melting-flow and thermal and mechanical properties show that the phonelic resin as binder has the advantages of good melting-flow and binding-firm and low-temperature-curing but its thermal and mechanical performances are weak and there is volatile molecules as NH3 and H2O generating during thermal-setting and the polyimide resin thermal and mechanical performances are strong and there is no volatile molecules generating but the setting temperature is a little high and the melting-flow property is too bad which can be improved by fastening temperature-rise rate and raising hot-pressed-forming pressure.It is pointed out that resin-bonded cubic boron nitride grinding wheels in nature belong to resin matrix composite materials but the CBN grains primarily act as cutting edges not incrementing components. Based on the theory of composite materials, this paper analyzed the binding interface of resin and abrasive grains and several methods for increasing the binding strength are proposed. Inorganic fillers such as coppers, white corundums, graphites, molybdenum sulfides, zinc oxides, chromic oxides and cryolites effecting on the mechanical and grinding perfomances of resin-bonded grinding wheels and their adding volume fraction are also researched. Epoxy resin is used for increasing the binding strength between CBN grains and resin by coating on the surface of CBN grains because the molting-flow rate and adhesive capability is good and it can react with phenolic resin and polyimide resin.On the results of the prior conclusions, phenolic resin and polyimide resin bonded grinding CBN wheels are individually manufactured with CBN grains concentration 125%, grit 140/170, by adjusting volume proportions of every ingredient. Comparison of grinding experiments indicated that both can be used for finish-grinding 45# harden steel by selecting suitable grinding conditions and the polyimide resin bonded CBN grinding wheel performed ever more wear-resistant property.
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