不同的造孔剂对陶瓷结合剂cBN砂轮性能的影响

Influence of Different Type of Pore Former on the Mechanical Property of Vitrified Bond cBN Grinding Wheel

砂轮中具有适量的气孔可以在磨削的过程中起良好的冷却、容屑排屑及促使砂轮自锐的作用。选用四种不同的造孔剂,在相同的试验条件下,通过添加不同含量的造孔剂,对比和分析了造孔剂的种类与用量对结合剂强度及砂轮性能的影响。试验结果为:添加4种不同的造孔剂均对结合剂的强度有一定的影响,造孔剂的含量越高,结合剂的强度下降幅度越大。氧化铝空心球及空心玻璃微球造出的气孔比较均匀,且孔隙率比较容易控制,制备出的砂轮在磨削的过程中容易产生较多的气孔,兼顾了砂轮的强度与锋利性。以硫酸铵为造孔剂制备的砂轮气孔比较细小而均匀,而且气孔之间是连通的,但硫酸铵对结合剂的强度影响较大,不宜过多添加。以碳粉为造孔剂制备的砂轮中有轻微的碳粉残留,对砂轮的强度影响较大。

Appropriate amount of pores in the grinding wheel will help the cooling and selfsharpening of the grinding wheel and provide space for chips and remove the chips during grinding operation.Four different types of pore former are selected for the experiment.Under the same experimental conditions,different content of pore former is added in order to compare and analyze the influence on the binding agent strength and the grinding wheel property caused by different type and content of pore former added.The result shows the binding agent strength has been affected by adding different type of pore former,binding agent strength declines more as pore former content increase.Pores created by alumina bubble and hollow glass microsphere are relatively uniform and porosity is relatively easy to control,so the grinding wheel product will generate more pores during grinding operation.In this way,both of the strength and sharpness of the grinding wheel have been obtained.Grinding wheel produced with ammonium sulfate as pore former has smaller uniform pores which are connected.It is not recommended to add much of ammonium sulfate as it has litter influence on the binding agent strength.Grinding wheel produced with carbon powder as pore former has slight carbon powder residual in the wheel,which has a significant influence on the strength of the grinding wheel.