| Combine the two lubrication way of adding a solid lubricant and in-situ reactionlubrication,in the process of designing ceramic cutting tool. With Al2O3as matrixmaterial, TiB2as enhancement phase, CaF2as a solid lubricant, Al2O3/TiB2/CaF2(ABF)self-lubricating ceramic tool was produced. The CaF2has lubricating effect in awider temperature range, In high temperature TiB2oxidation reduction generatedTiO2and B2O3that has lubricating effect to achieve the goal of improve overalllubrication performance of the cutting tool.Choose suitable type of self-lubricating material system according to the generalidea of designing ceramic cutting tool, and then analyzes its corresponding physicaland chemical compatibility. Using gibbs free energy function method to calculate andanalyze whether the components react in a vacuum sintering process from theoretical.Finally is confirmed through XRD test.ABF self-lubricating ceramics cutting tool materials were produced by a series ofprocess with the ball mill, desiccation, cold pressing molding, hot-pressing. Testingits mechanical performance,and then got the optimum content of material of eachcomponent(Al2O3:TiB2=7:3,CaF25wt%),the best hot-pressing sintering process(sint-ering temperature is1700℃,holding time is20min,the thermal stress is30MPa).Under the optimum conditions,a relative density of96.5%,a flexure strength of685MPa, a hardness of16.4GPa,and a fracture toughness of3.7MPa·m1/2were obtainedfor ABF self-lubricating ceramic cutting tool material. The surface microstructure andfracture surface was observed, its good compactness, holes, the fracture form belongsto a mixture of transgranular fracture and intergranular fracture.Using ball plate pair to carried out friction and wear experiment with carbide(YG6X).The result showed that the friction coefficient showed a trend of decline asincrease of CaF2content, load and speed. The friction and wear morphology wasobserved, and found that the lubricating film formation is the main reason for declinethe coefficient of friction. Cutting performance of the ABF self-lubricating ceramiccutting tool was compared with the ordinary ceramic cutting tool(AG2) when drycutting45#steel,The result showed that ABF tool can effectively reduce the cuttingforce and friction coefficient in the process of cutting. Its friction coefficient reducedrate faster When the speed is130m/min. Through XRD spectrum analysis. B2O3andTiO2of the lubrication effect was produced by The redox reaction. ABF self-lubricating ceramic cutting tool is more suitable for high-speed dry cutting tool toachieve the combination of the two lubrication, the effect is more pronounced. Twotools of flank face all belong to typical characteristic of abrasive wear. |
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