Synthesis Of High Quality CVD Diamond And Research On Its Application In Graver

Diamond is an excellent material and has high application value. Natural diamond isexpensive that restricts its application. High quality CVD diamond has approached naturaldiamond in some physical and chemical properties. Because of its large-area flaky shape, CVDdiamond film is endowed more advantage in application. Research on diamond film's growthproperties is a hot problem. Also, more and more researchers focus on diamond film'sapplication these years.In this paper, we synthesized diamond films on Mo substrate with hot cathode DC plasmachemical vapor deposition method. CH₄,H₂ and CO₂ were used as gas source and their flowswere 8sccm, 200sccm and 0-2sccm, respectively. SEM,XRD and Raman were used tocharacteristic films'morphology, structure and quality. The results indicate: with the increase ofCO₂ flow, the film became dense; Without CO₂addition, the film had a (100) orientation. WhenCO₂ flow up to 2sccm, (111) orientation was dominating. In the middle, (110) orientation wasthe main film orientation. XRD verified the structure's differences of all samples;Accompanying the increase of CO₂flow (0.5-2sccm), the I₁₁₁/ I₂₂₀ ratio increased from 0.02 to5.26, that exceeded natural diamond standard power's I₁₁₁/ I₂₂₀ ratio (3.7); Without CO₂additionor CO₂flow is 0.5sccm, the film had a bad quality because the graphite existed in the film. Thegraphite peak that aligned at 1580cm-1 in Raman spectra disappeared when CO₂ flow exceed0.5sccm. As was also seen, the compressive stress changed to tensile stress when CO₂flow is0.89sccm and the growth rate decreased with the addition of CO₂. High quality diamond films'growth rate can reach 12um/h.Additional, we designed and manufactured a kind of CVD diamond graver that can be usedcarving small words on the surface of granite. We design orthogonal experiment. The varianceanalysis of experimental results indicating: cutting speed had a very significant influence ongraver life. Feed rate had a significant influence on graver life except depth of cut. Multipleregression analysis is made to get experienced life equation. The main wear mechanism is abrasive wear. We put forward wear process thorough observing wear morphologies.