Now showing 1 - 2 of 2
  • Publication
    Manufacturing of CVD diamond micro-end mills with electrical discharge machining
    ( 2017)
    Uhlmann, E.
    ;
    Oberschmidt, D.
    ;
    Polte, M.
    ;
    Polte, J.
    ;
    Schimmelpfennig, T.-M.
    ;
    Börnstein, J.
    At state of the art micro-milling tools made of cemented carbide are widely used in industry. Nevertheless, these micro-milling tools suffer from fast and random tool breakage while cutting. To improve the wear behaviour of micro-milling tools new cutting materials have to be established. In this work electrical discharge machining (EDM) for manufacturing of micro-milling tools with cutting edges made of boron doped chemical vapour deposition (bdCVD) diamond were investigated. Wire-EDM and die-sinking-EDM were compared regarding the characteristics of the micro-tool´s cutting edges. It could be concluded that the wire-EDM process is suitable for manufacturing of micro-milling tools with cutting edges made of bdCVD diamond. With respect to the elaborated technologies for the wire-EDM process a cutting edge radius rv = 3.9 mm and for the die-sinking-EDM process a cutting edge radius rv = 5.4 mm could be measured.
  • Publication
    CBN-micro-milling tools for machining hardened steel moulds
    ( 2016)
    Uhlmann, E.
    ;
    Oberschmidt, D.
    ;
    Polte, M.
    ;
    Polte, J.
    ;
    Börnstein, J.
    High-precision cutting of hardened steel with geometrical defined cutting edge is restricted due to excessive and random tool wear. For serial production of precision plastic parts hot embossing tools and micro injection moulding tools with high requirements regarding geometrical accuracy and surface roughness are needed. Cutting materials based on cubic Boron Nitride (cBN) are successfully used in macro-machining of hardened steel. In this paper, detailed information about machining hardened steel with micro-milling tools with cutting edges made of cBN are given. An arithmetical mean deviation Ra = 19 nm could be achieved using a high-precision micro-milling machine tool with ball bearing guideways and spindle.