Experimental Study On Grinding Process Of Revolution Surface Of Certain Silicon Nitride Ceramic Typical Part

With the rapid development and wide application of aviation and aerospace,high-precision instruments, inertial navigation platform, optics and laser technology,all kinds of high precision complex parts, optical components, high-precision curvedsurface and the processing of complex shapes are increasingly urgent. Currently,processing on high hardness ultra-precision brittle materialsare as mainly achieved bysuper-hard abrasive precision grinding and lapping, polishing. Conventional surfacegrinding process is carried out by two main methods. One way is by forming wheelprocessing, which although efficient, having some problems such as long wheeldressing, wheel wear and low shape accuracy after processing; the other is by sharppoints processing, which grinding wheel is dressed into V-type and fixed up, then thesharp points for dressing on the wheel surfaceformed, but wheels easy to wear andaccuracy difficult to ensure.In this paper, the experimental platform for NC grinding silicon nitride ceramicrevolution surface was built for this typical parts, with high precision NC coordinategrinder MK2945C.Forming principle and process of revolution surface with thegrinding wheel normal tracking were analyzed and numerical control programming andNC grinding were carried out; Two mathematical models about surface scallop heightafter grinding respectively for convex surfaces and rotating concave surfaces wereestablished. The influences of radius of the grinding wheel, grinding wheel feed rate,workpiece radius and speed on scallop height after grinding were analyzed. And alsothe feed rate of the grinding wheel with variable curvature was optimized and theoptimization curve obtained based on the constant scallop height method; Designed thegrinding scheme for revolution surface of this silicon nitride ceramics part. Accordingto the characteristics of grinding wheel tracking method，single factor experimentalprogram was developed, and experimental process parameters set; With single factorexperiment, the grinding surface roughness experiment of grinding revolution surfacesof silicon nitride ceramics part was carried out and compared with theoreticalcalculation grinding surface scallop height, which showed change coincidencebetween surface roughness and grinding surface scallop height.The influences ofvarious process parameters on the grinding surface roughness were analyzed andmeasures put forward to improve the surface roughness;Study on grinding mechanismof revolution surface of silicon nitride ceramics part. The single factor experiments were carried out by varying four key process parameters including feed rate of wheel,circular linear speed, grain size, grind depth which influence surface quality. Theinfluences of each process parameters on the grinding material removal mechanism ofcertain typical part revolution surface were analyzed by observing the ground surfacetopography, and specific measures proposed to improve the grinding surface quality ofthis certain typical part revolution surface.A new revolution surface grinding,wheel normal tracking method,was taken inthis paper and process parameters theoretically analyzed and optimized;specificmeasures to improve the grinding surface roughness and quality of ceramics werepresented, and the grinding of certain silicon nitride ceramic typical part was carriedout, which shows the technology is stabled and reliabled, and has important value.