石墨烯对聚晶金刚石的影响试验研究

Experimental study on the influence effect of graphene on the polycrystalline diamond

石墨烯是近几年来新兴的一种具有多项优异性能的材料,在许多领域已经开展了研究和应用,如陶瓷复合材料、铝合金复合材料等,都取得了一定的效果。文章把石墨烯加入到聚晶金刚石中,以期提高聚晶金刚石的性能,以满足深孔坚硬岩层复杂条件下的钻探需求。研究了石墨烯-金刚石复合粉末的混合工艺,在1400℃~1500℃,5.0 GPa~5.5 GPa条件下烧结制备了石墨烯含量分别为0.05 wt%、0.10 wt%、0.20 wt%、0.30 wt%的聚晶金刚石,并对这些聚晶金刚石进行了相对密度、导热性和导电性等物理性能测试,以及磨耗比和抗冲击性等力学性能测试。结果表明:湿混比干混分散得更加均匀,但是烧结出的聚晶金刚石性能方面干混的磨耗比最高,比不添加石墨烯组整体上提高了70%~80%。石墨烯浓度为0.10 wt%且混粉方式为干混的条件下,功率为7.2 kW的磨耗比最高,平均磨耗比达22万。相对密度、导热性、导电性和抗冲击性能测试都表明石墨烯浓度为0.10 wt%时最优,且干混比湿混更好。

Graphene is a new kind material with excellent properties in recent years.It has been studied and applied in many fields,such as ceramic composites and aluminum alloy composites,and there has achieved for the great result.In this paper,graphene is added to the polycrystalline diamond in order to improve the performance of polycrystalline diamond and to meet the drilling needs of deep hard rock under the complex condition.In this paper,the mixing process of graphene and diamond composite powder is studied.Polycrystalline diamonds with graphene content of 0.05 wt%,0.1 wt%,0.2 wt%and 0.3 wt%are prepared by sintering at 1400℃-1500℃and 5.0 GPa-5.5 GPa.The physical properties such as relative density,thermal conductivity and conductivity,wear ratio and impact resistance of the polycrystalline diamonds are tested.The result shows that wet mixing disperses more evenly than dry mixing,but the wear ratio of dry mixing is the highest in the properties of sintered polycrystalline diamond,which is 70%-80%higher than that of the group without graphene.As the concentration of graphene is 0.1 wt%and the mixing method is dry mixing,the wear ratio is the highest with power of 7.2 kW,and the average wear ratio is 220000.The test result of relative density,thermal conductivity,conductivity and impact resistance indicates that the optimum concentration of graphene is 0.1 wt%,and dry mixing is better than wet mixing.