development of micro crystalline diamond on cemented carbide inserts by hfcvd method for machining of aluminium

Abstract

Diamondisthehardestknownmaterialandhasbeenavailableinitsnaturalform newlinefor a long period. Natural diamond is used as cutting tools in special applications, newlinewhere no other tools can operate satisfactorily. High quality diamonds are used newlineto and#64257;nish theturning of gold, copper etc. On the other hand, low quality industrial newlinediamonds are extensively used in high speed machining of non-ferrous materials, newlineceramics and plastics. There is a rapid development can be observed in the and#64257;eld newlineof metastable synthesis of diamond using Hot Filament Chemical Vapor Deposition newline(HFCVD) technique. This HFCVD technique is a well-established method to newlinesynthesizediamondthinand#64257;lmsonanon-diamondsubstrate. Inthispaper,theMicrocrystalline newlinediamond (MCD) was deposited on WC 6 wt. % Co cutting tool inserts newlinebyHFCVD technique.The substrate was pretreated by chemical etching(HCL+HNO3+H2O) at newlineratio (1:1:1)) to reduce surface cobalt and then ultrasonically seeded with diamond newlinepowdertoimprovethenucleationandgrowthofthediamond. TheMCDtoolswere newlinecharacterized by the scanning electron microscope (SEM) and X-Ray Diffraction newline(XRD).ThepurityofthediamondwasassessedbyusingMicroRamanspectroscopy newline(µand#8722;RS). AcomparisonwasmadeamongtheMCDtoolsweretakenuncoatedtungstencarbide(WC)toolandpolycrystallinediamond(PCD)toolduringthedryturningofaluminum. newlineThevariousmajortestswereconductedsuchassurfaceroughness, newlinecuttingforceandtoolwear. Theyweretakenintoconsiderationtoestablishaproper newlinecomparison among the advanced cutting tools. Moreover, and#64257;ve other advanced cuttingtoolssuchasWCSPUN,WCSPGN,WC+TiN,WC+Ti(C,N)+Al2O3 newlineandPCDwereutilizedfortheexperimentstoand#64257;ndoutasuitablecuttingconditionfor newlinedry machining of aluminium. It was found from the results that PCD was the best newlinetoolamongall. Atthesametime,thePCDtoolagaincomparedwiththeMCDtool. newline newline newline