| With the rapid development of rail traffic,the maintenance for grinding of railway rails has become extremely significant.At present,resin grinding wheel is the main tool for rail grinding,exposing problems such as low material removal rate and high grinding temperature.In response to above problems,a new ceramic-metal bond CBN(cubic boron nitride)polymer was developed by using brazed super-hard abrasive technology,and its physical and chemical analysis and grinding performance were studied.The main work of this paper is:(1)Determination of ceramic bond formulation.The boron aluminum silicate glass system was selected as the basic system of the ceramic bond,and the components of the bond were determined.The ceramic bond was finally obtained through following steps: weighing,mixing,melting under high temperature,water quenching,drying,ball milling and sieving.(2)Design of polymer forming mold.In order to consolidate the mixture of ceramic bond,alloy solder,cubic boron nitride abrasive and auxiliary additives into a green body with a certain shape,size,density and strength,a polymer-specific pressing mold was designed.The size design and material selection of cavity block,upper die punch and the lower die punch were made.The stress and strain analysis of the die with the ABASQUS software verified that the die could fully meet the strength requirements.(3)Preparation of ceramic-metal bond CBN polymer.The procedure is listed.Firstly,use Cu-SnTi alloy solder and select 30/35 mesh cubic boron nitride.Secondly,mix ceramic bond,metal solder,cubic boron nitride and green binder.Then use homemade mold to press for formation.When it was brazed in a vacuum brazing furnace with the temperature of 950?,holding time of 30 minutes,and then cooling with the furnace to obtain a ceramic-metal bond CBN polymer.(4)The physical and chemical analysis and grinding performance of ceramic-metal bond CBN polymer.Using stereo microscope,scanning electron microscope,and energy spectrometer to analyze the morphology and physical and chemical analysis of the brazed polymer,it was found that the polymer solder layer had a good degree of brightness and compactness,and the solder had a good infiltration of cubic boron nitride,which achieved a good embedding effect on cubic boron nitride.The grinding performance of the resin zirconium corundum and the ceramic-metal bond CBN polymer was compared and analyzed through a grinding test.The test results show that compared with the resin zirconium corundum,the ceramic-metal bond CBN polymer has a higher material removal rate and lower grinding temperature. |
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