De-coating technique for CVD diamond coatings and evaluation of performance for recycled cutting tools

For the recycling of CVD (chemical vapor deposition) diamond coated cutting tools, a mechanical method, where old films were partly ground and re-coated, has been conducted. However, because of some problems it is not considered as an effective method. In order to overcome these difficulties, the authors have recently proposed a new technique for de-coating the diamond coatings on tools completly by combustion in a high temperature. This article clarifies the mechanism of the de-coating method, and proposes the treatment method for tools with different coating lengths. The examples of treatment conditions for de-coating obtained from the test results are reported in this paper. The durability cutting tests were performed with the regenerated tools. Finally the effectiveness of this technique was verified by the cutting tests.