The Research Of Friction And Lubrication Chracteristics In Warm Plastic Forming Process Of Typical Automobile Shell Part

The typical automobile shell part-car accumulator shell is an important part in carhydraulic system. It works under the most pressure and plays an important role in thenormal operation, working stability and working life of the car, so it has high formingprecision and mechanical performance requirements. Warm plastic forming technology is akind of precision or half precision forming technology, which has the advantages of hotforming and cold forming and voids the deficiency of both. It can ensure the formingprecision and reduce the forming force, always used in the forming of parts with complexshape. It will bring huge economic and social benefits that the processing and massproduction of such parts is conducted with warm plastic forming technology. In metalplastic forming process, the pressure at the tool-workpiece interface is extremely high, thefriction at the interface has great influence on the whole plastic forming process and thequality of formed parts, reasonable lubrication measures are very important. So theresearch of friction and lubrication characteristics in warm plastic forming process of thetypical automobile shell part is of great significance.First, the numerical simulation analysis of warm plastic forming process of the typicalautomobile shell part under different process conditions was conducted with Deform-3Dincluding the overall situation of the deformation, the flow of metal material in the formingprocess and the effect of key process parameters on forming load, then the best processparameters were determined by using the orthogonal experiment with the forming load asjudging standard. Second, the numerical simulation analysis of the wear of the bottom diein warm plastic forming process of the automobile shell part was conducted based on themodified Archard wear model with Deform-3D including the overall wear situation of thebottom die and the effect of key process parameters on maximum wear depth. Third, thewater-based warm extrusion lubricants were configured in this paper based on the study of plastic forming lubrication theory and the existing warm extrusion lubricants, then thepractical application of the lubricants was studied through the high temperature friction andwear tests, the warm extrusion tests of the actual parts and SEM observation of the surfacemorphology of the formed parts. The actual effect of the lubricants was quantitativelyexpressed as friction factor through ring compression test. Finally the dispersion ofnano-graphite in water was explored with physical and chemical method based on theexisting nano-particles dispersion stability theory, and good dispersion effect was obtainedpreliminarily. The configuration and performance study of the nano-graphite lubricant werealso conducted.