Multi-layer structure for chemical vapor deposition diamond on electroplated diamond tools

In this work we established a process to overcome the deposition difficulty on electroplated diamond tools by a multi-layer structure. The process consists of the following steps: (1) diamond powder aggregation with nickel (this step is the conventional method for the production of electroplated tools); (2) electrochemical deposition of a chromium layer, but leaving the diamond grains partially uncovered; (3) nitridation of the chromium layer; and (4) deposition of the chemical vapor deposition (CVD) diamond layer. This method uses the advantages and overcome the disadvantages of each step. Electroplating with nickel is conventionally used due to its relatively good wettability to diamond. The direct aggregation of the diamond powder with a chromium layer results in looser grains and is not usable. The nickel laver is inadequate for diamond deposition; even after treatment in hydrogen atmosphere, diamond does not grow on it. The chromium nitride layer is well known to be very suitable for diamond growth, however, the thermal stress between these Layers is very high limiting film thickness and its applicability. With the multi-layer structure obtained the CVD diamond him is deeply anchored by the diamond grains into the metal matrix and helps considerably to decrease the stress. The process has been developed on flat surfaces and tested on small conventional diamond burrs. The diamond films have been characterized by scanning electron microscopy (SEM), energy dispersive X-rays (EDS) and Raman spectroscopy (RS), (C) 2001 Elsevier Science B.V. AIL rights reserved.