Accession Number : ADA257552


Title :   A Comparison Study of Diamond Films Grown on Tungsten Carbide Cobalt Tool Inserts with CH(4) and CF(4) Gas Sources


Descriptive Note : Technical rept.


Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF MATERIALS SCIENCE AND ENGINEERING


Personal Author(s) : Grannen, K J ; Xiong, F ; Chang, R P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a257552.pdf


Report Date : Nov 1992


Pagination or Media Count : 32


Abstract : The results of a comparison study of continuous diamond coatings deposited on tungsten carbide-6% cobalt tool inserts using CF4, and CH4, gas sources are presented. The CH4, grown diamond film utilizes a thin (1200 A) amorphous silicon interlayer for adhesion while the CF4, diamond film is deposited directly onto the tool insert. Diamond films produced with CF4, gas have much higher growth rates and better adhesion than diamond films grown with CH4, gas. The films are characterized by scanning and transmission electron microscopy, and Raman spectroscopy to determine film crystallinity and quality. Macroscopic indentation tests have been conducted to determine the adhesion of the films to the substrate, and an aluminum-17 % Si alloy is machined with the diamond-coated tool inserts to determine their performance in a machining environment. A mechanism for the growth of diamond on tungsten carbide-cobalt using CF4, gas is postulated.


Descriptors :   *TOOLS , *CRYSTAL GROWTH , *DIAMOND FILMS , *TUNGSTEN CARBIDES , ALUMINUM ALLOYS , COMPARISON , ADHESION , VAPOR DEPOSITION , SCANNING ELECTRON MICROSCOPY , COBALT , INSERTS , NUCLEATION , ELECTRON MICROSCOPY , COATINGS , SILICON , TUNGSTEN


Subject Categories : Coatings, Colorants and Finishes
      Machinery and Tools
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE