微细金刚石颗粒表面涂覆Ni-P合金及其加工性能评价

发布时间：2018-03-11 22:24

本文选题：金刚石微粉　切入点：化学镀　出处：《南京航空航天大学》2015年硕士论文　论文类型：学位论文

【摘要】：固结磨料研磨技术具有绿色环保、加工成本低和加工效率高等特点,是近年来迅速发展起来的一种研磨加工新工艺。金刚石磨粒是固结磨料研磨的常用磨料,但是由于金刚石颗粒在加工过程中易脱落,利用率大大降低;在金刚石磨粒表面镀镍可以提高树脂基体对磨粒的把持能力,进而提高金刚石的利用率。本文通过化学镀镍的方法,在金刚石微粉表面镀覆一层Ni-P合金层;并使用镀镍金刚石微粉制备了固结磨料研磨垫,通过连续研磨实验和相关测试系统对金刚石形貌及其加工性能进行了评价。主要研究内容和结果如下:(1)研究了络合剂及还原剂对镀层P含量及包覆率的影响,并通过SEM观察了不同P含量下金刚石颗粒的微观形貌。结果表明:同等条件下,络合剂的络合能力越强镀层P含量越高,还原剂含量越高镀层P含量越高;络合剂络合能力越强镀层包覆率越低,还原剂含量越高镀层包覆率越高;镀覆后金刚石颗粒的表面粗糙度随着P含量的上升而增大。(2)探索了不同镀层P含量金刚石在固结磨料垫中的加工特性,对比了不同研磨垫加工过程中的摩擦系数、声发射信号、材料去除率、工件表面质量以及加工后研磨垫的磨损量;并与电镀金刚石进行了对比。结果表明:研磨过程中的摩擦系数、材料去除速率和工件表面粗糙度随着P含量的增加呈先增大后减小的趋势;中磷镀层金刚石研磨垫的加工效率及其稳定性最好,连续加工50 min后材料去除速率为6.4μm/min,保持度为58.8%,约为低磷金刚石保持度的1.2倍;研磨后研磨垫的磨损量随着P含量的增大而降低;电镀金刚石表面粗糙度及加工性能均介于低磷与中磷镀层金刚石之间。(3)不同研磨阶段的金刚石在研磨过程中的受力与接触状态存在较大的差异,分别对两种不同粒径的金刚石表面镍覆量进行了优化,并进行了对比。结果表明:粗研过程使用的粗粒径金刚石在研磨过程中的受力及对磨粒把持力的要求均高于细粒径的精研金刚石,所以对镀层表面粗糙度的要求也高于精研金刚石;在研磨K9玻璃过程中40-50μm的金刚石在包覆率50%时研磨效率达到最大值,20-30μm的金刚石在包覆率30%时研磨效率达到最大值。
[Abstract]:The technology of consolidated abrasive grinding has the characteristics of green environmental protection, low processing cost and high processing efficiency. It is a new grinding technology developed rapidly in recent years. However, diamond particles are easy to fall off in the process of processing, and the utilization ratio is greatly reduced. Nickel plating on the surface of diamond abrasive particles can improve the ability of resin matrix to control the abrasive particles. In this paper, a layer of Ni-P alloy layer was coated on the surface of diamond powder by electroless nickel plating, and a cemented abrasive grinding pad was prepared using nickel coated diamond powder. The morphology and processability of diamond were evaluated by continuous grinding experiment and related testing system. The main research contents and results were as follows: 1) the effects of complexing agent and reducing agent on P content and coating rate were studied. The microcosmic morphology of diamond particles with different P content was observed by SEM. The results showed that the stronger the complexing ability of the complexing agent was, the higher the P content of the coating was, and the higher the P content of the coating was, the higher the content of reducing agent was, the higher the P content of the coating was. The stronger the complexing ability of the complex agent is, the lower the coating coating is, and the higher the content of reducing agent is, the higher the coating coating rate is. The surface roughness of coated diamond particles increases with the increase of P content.) the processing characteristics of diamond coated with different P content in consolidation abrasive pad are explored, and the friction coefficient and acoustic emission signal of different abrasive mats are compared. The material removal rate, the surface quality of workpiece and the wear amount of abrasive pad after finishing are compared with those of electroplated diamond. The results show that the friction coefficient in the grinding process, The material removal rate and workpiece surface roughness increased first and then decreased with the increase of P content, and the processing efficiency and stability of medium phosphorus coated diamond lapping pad were the best. After 50 min of continuous processing, the material removal rate was 6.4 渭 m / min, and the retention was 58.8, about 1.2 times of the retention of low phosphorus diamond, and the wear rate of grinding pad decreased with the increase of P content. The surface roughness and processability of electroplated diamond are between low phosphorus and medium phosphorus coated diamond. The nickel coating on diamond surface with two different diameters was optimized. The results show that the force and holding force of rough diamond in grinding process are higher than those in fine grain grinding process. Therefore, the surface roughness of the coating is higher than that of fine grinding diamond, and the grinding efficiency of 40-50 渭 m diamond in K9 glass grinding process reaches the maximum when the coating rate is 50 渭 m and the grinding efficiency of diamond with 20-30 渭 m coating ratio reaches the maximum when the coating rate is 30 渭 m.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163;TB306

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