Preparation and Characterization of Ni Spines Grown on the Surface of Cubic Boron Nitride Grains by Electroplating Method.

Yanghai Gui,Yuanli Jiang,Jianbo Zhao,Jingbo Chen

doi:10.3390/ma9030153

Abstract

Cubic boron nitride (cBN) is widely applied in cutting and grinding tools. cBN grains plated by pure Ni and Ni/SiC composite were produced under the same conditions from an additive-free nickel Watts type bath. The processed electroplating products were characterized by the techniques of scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermoanalysis (TG-DTA). Due to the presence of SiC particles, there are some additional nodules on the surface of Ni/SiC plated cBN compared with the pure Ni plated cBN. The unique morphology of Ni/SiC plated cBN should attain greater retention force in resin bond. Moreover, the coating weight of cBN grains could be controlled by regulating the plating time. cBN grains with 60% coating weight possess the optimum grinding performance due to their roughest and spiniest surface. In addition, Ni spines plated cBN grains show good thermal stability when temperature is lower than 464 °C. Therefore, the plated cBN grains are more stable and suitable for making resin bond abrasive tools below 225 °C. Finally, the formation mechanism of electroplating products is also discussed.

Highlights

It is well known that the superabrasive Cubic boron nitride (cBN) has many excellent properties such as high thermal conductivity, high stability, superhardness, wide bandgap, good optical transparency in a wide range [1,2,3,4,5]
The substrates that used as cathode were cBN grains of 100/120 mesh (125–150 μm), which were processed through the following steps: oil removal, roughness, sensitization-activation, reduction and chemical plating processing before electroplating [13]
The scanning electron microscopy (SEM) images of raw cBN grains, pure Ni plated cBN and Ni/SiC plated cBN are shown in plated cBN grains (Figure 1c–e), but none is on the surface of pure Ni plated cBN grains (Figure 1b)

Summary

Introduction

It is well known that the superabrasive cBN has many excellent properties such as high thermal conductivity, high stability, superhardness, wide bandgap, good optical transparency in a wide range [1,2,3,4,5]. These merits make cBN the unrivaled material for the fabrication of cutting tools, grinding materials, super-hard protective coatings, optoelectronic devices, etc. An effective way to improve the adhesion between cBN grains and resin matrix is to plate Ni metal on the surface of grains, which has been proved in practice application.

Methods

Results

Conclusion