The Study Of Electroless Composite Ni-P-PTFE-SiC Plating

This paper studies the electroless plating techniques for the deposition of Ni-P and composite plating Ni-P-PTFE . Ni-P-SiC. We make use of double complexing agents and double quickening agents in the composite plating techniques which enable to increase the deposition rate and to obtain a more stable plating bath. Then we obtain the Ni-P-PTFE-SiC composite technique successfully on the basis of these two composite techniques. The thesis focuses on the study of the effects of the amount of SiC and PTFE particles on the deposition rate and the content of different particles in the composite coatings .The result shows that the deposition rate is quicker , the content of SiC and PTFE particles in the coating is medium and the plating bath is stable with the addition of 10~25 g/1 SiC particles and 5~20 ml/1 PTFE particles in the bath. At the same time, we studies the property of the composite coatings. The First, we studies the composition and structure of the coatings by means of the X-ray diffraction and SEM.The XRD spectra demonstrates that the Ni-P-PTFE-SiC composite coating is non-crystalline. On the SEM photograph of the coating, we can see the distribution of the PTFE and SiC particles clearly. Secondly, we discuss the hardness and wear resistance of the coatings. The results indicated that the hardness of the coating decreased because of the addition of the soft particles-PTFE. But the wear performance showed that the wear capacity reducedconsiderably and it had a lower friction coefficient. This is because a solid film can be formed in the coating containing PTFE. It features good lubricity, less friction coefficient. At the same time, the SiC particles can improve the wear resistance of the coating. Thus, we obtain a composite coating with stronger wear resistance and low friction coefficient.Therefore, the composite coating of Ni-P-PTFE-SiC is one of the most successful coatings for preventing wear and for relatively low friction.