The performance of diamond impregnated bit had great influence on the efficiency and cost of geological exploration drilling.To improve bit performance, a new type of diamond impregnated drilling bit enhanced with CVD diamond pins was designed and manufactured in this research.The dimension and number of CVD diamond pins and their arrangement in the bit matrix were designed.The hardness of bit matrix, the size and concentration of diamond grits and bit structure were designed according to the drillability and abrasiveness of the rock to be drilled.φ59 mm specimen bits were manufactured by the method of intermediate frequency hot pressing.Percussive rotary drilling tests using these bits were conducted.The drilling results indicated that the bits enhanced with CVD diamond pins demonstrated higher drilling efficiency and superior impact resistance compared with the bit inserted with soft pins (graphite).In contrast with pure rotary drilling tests, the new type bits obtained a higher drilling efficiency ( up to 2.84 m/h ).In addition, the drilling process was more steady.%孕镶金刚石钻头的性能对地质勘探钻进的效率和成本有很大的影响.为了提高钻头的性能,本文设计、制造了一种用CVD金刚石条作为硬支点材料的新型孕镶金刚石钻头.设计了CVD金刚石务的尺寸、数量及在钻头胎体上的排列方式.根据被钻岩样的可钻性及研磨性,设计了钻头胎体硬度、金刚石粒度、浓度及钻头结构.采用中频感应热压法制造了φ59 mm硬支点孕镶金刚石钻头,并进行了冲击回转钻进试验.试验结果表明:与软支点孕镶金刚石钻头相比,在冲击回转钻进试验中,硬支点钻头的钻进效率、抗冲击性能均优于软支点钻头;与纯回转钻进试验相比,钻头的平均时效更高,达2.84 m/h,且钻进性能更加稳定.
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