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Dry Cutting (dry + cutting)
Selected AbstractsCrystalline , -Alumina Deposited in an Industrial Coating Unit for Demanding Turning Operations,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Kirsten Bobzin Crystalline PVD ,-Al2O3 - coatings offer great potential for their use in high-speed cutting operations. They promise high hot hardness and high oxidation resistance at elevated temperatures. This is important for coatings that are used for machining of materials with low thermal conductivity such as stainless steel or Inconel 718 because heat generated during cutting can barely be dissipated by the chip. Because of the prevailing bonding forces of alumina, adhesion-related sticking can be reduced even for dry cutting. Furthermore, the high formation enthalpy of alumina prevents chemical reactions with frictional partners. The present work gives an overview of the deposition of ,-Al2O3 thin films on WC/Co-cutting inserts by using pulsed MSIP (magnetron sputter ion plating) PVD technology. To improve adhesion, a (Ti,Al)N bond coat was employed. The samples were analyzed using common thin film test equipment. Cutting tests and pin-on-disk examinations were carried out to test the coating's performance. For turning operations, the difficult-to-machine austenitic steel 1.4301 (X5CrNi18-10) was used. In comparison to a state-of-the-art (Ti,Al)N coating, (Ti,Al)N/,-Al2O3 showed a longer tool life. [source] Influence of Surface Modification on the Cutting Performance of Reaction-Sintered Al2O3,TiOC CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2008Anup K. Bhattacharya Al2O3,TiC mixed ceramics are popular for dry cutting of hardened steel. In this work, the cutting performance of surface-modified mixed ceramic cutting tools has been studied. A 1-,m-thick modified surface has been obtained by CO2 posttreatment of the Al2O3,TiOC mixed ceramics. The cutting performance of the modified tools has been found to be much better than the precursor-mixed ceramics. The density of the modified layer also has an influence on the cutting performance. Modified ceramics with a dense surface layer show considerably improved wear resistance compared with that of ceramics with a porous layer. While plastic deformation of the TiC layer in the flank surface, followed by abrasive wear of the exposed substrate is responsible for flank wear, crater wear is caused mainly by diffusion reaction as well as by abrasion. In our system, it is mainly the flank wear that controls the cutting performance of the inserts. [source] Werkzeugbeschichtungen für die Trockenbearbeitung,MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 10 2006E. Abele PVD coating; tribology; dry machining; tool wear Abstract Bei der Trockenbearbeitung wirkt an der Werkzeugschneide ein Belastungskollektiv aus mechanischen, thermischen und chemischen Einflussgrößen. Im Vergleich zur konventionellen Bearbeitung unter Verwendung von Vollstrahl-Emulsionskühlung erhöht die Trockenbearbeitung die auf den Schneidkeil wirkenden Belastungen. Eine sehr gute Möglichkeit die Schneide vor thermischen, abrasiven und tribo-oxidativem Verschleißangriff zu schützen stellt die Verwendung von PVD Beschichtungen dar. Neu entwickelte PVD Beschichtungen aus CrxAlyYzN, CrxAlyBzN und CrxAlySizN- wurden sowohl im tribologischen Modelltest als auch im realen Zerspanungstest auf ihre Eignung zur Trockenbearbeitung untersucht. In diesem Paper wird neben der verwendeten Beschichtungstechnologie detailliert auf die Schichteigenschaften eingegangen. Im Zusammenhang mit dem im Zerspanungstest gemessenen Verschleißverhalten und der Prozesskräfte werden anschließend Rückschlüsse auf das weitere Optimierungspotential dieser Schichtsysteme gezogen. Tool coatings for dry machining During dry machining a strain collective consisting of mechanical, thermal, and chemical loads is imposed upon the cutting edge. Compared to conventional machining using cooling lubrication fluids, the loads are increased in dry cutting. A feasible solution to protect the cutting edge from thermal wear, abrasion, and tribo-oxidation is the application of hard coatings. Newly developed CrxAlyYzN, CrxAlyBzN and CrxAlySizN PVD coatings were both evaluated in tribological model tests and machining tests concerning their suitability for dry cutting applications. Herein, the used coating technology and the coating properties are described in detail. The measured tool wear and the process forces give further hints for the optimization of the coating system. [source] Nanocomposite AlTiNCO Coatings Deposited by Reactive Cathodic Arc EvaporationPLASMA PROCESSES AND POLYMERS, Issue S1 2007Jörg Vetter Abstract AlTiNCO coatings were deposited by the reactive cathodic arc evaporation. In addition, TiNC coatings with different carbon contents were deposited to compare the influence of carbon addition on the oxidation depth between TiNC and AlTiNCO coatings. Variations in microstructure, morphology, and chemical composition were correlated with mechanical properties. High-resolution transmission electron microscopy revealed that nanocrystalline phases are present. Higher carbon contents lead to the precipitation of free carbon resulting in a nanocomposite structure of AlTiNCO/C. Raman spectroscopy of the nanocomposite structure showed spectra typical of nanocrystalline carbon. It was shown that the additional carbon had a positive influence on the cutting performance in dry cutting. [source] | ||||||||||