MICROSTRUCTURE AND INTERFACES IN DIAMOND-COATED STEEL WIRES

Diamond fibres were produced in a hot filament reactor by chemical vap our deposition of a 40 mu m thick layer of diamond on to titanium-coat ed iron and iron-chromium wires. In the 40 h deposition time carbon di ffused through the titanium and steel and produced carbide microstruct ures with hardness values of similar to 3234 and 5390 N mm(-2) for the Fe and Fe-Cr cores, respectively. During cooling thermal stress fract ure of the diamond was avoided by stress relief cracks in the disorder ed graphite layer at the diamond/Ti-rich layer interface.