Entwicklung neuartiger Schneidstoffe fuer Hochleistungsverfahren der Zerspantechnik. Teilprojekt A: Entwicklung einer neuen Generation von Feinstkorn-Mischkeramik-Schneidstoffen Abschlussbericht

Cutting of chilled cast iron and hardened steel affords cutting materials with high hardness and wear resistance, even at high temperatures, as well as a superior strength in the cutting edge range. Actual cutting tool materials do not meet these requirements sufficiently, especially in interrupted cuts. CBN-materials can be used in some of these applications; since they are no economical alternative there is an urgent need for materials development in this area. The aim of the project was to develop a new generation of cutting tool materials upon the basis of the actual Alumina-Titaniumcarbonitride ceramic-composites which meet the defined necessities. In the same time it was necessary to develop the grinding process for hard machining the extremely wear resistant ceramic itself within the required precision. Extremely fine-grained microstructures in the alumina-titaniumcarbonitride composites yielded a remarkable increase of the mechanical properties. The transformation of these mechanical properties into application properties has been proven by a lot of application tests in the lab and in field-tests. The investigation of the influence of additional hard materials (Cr_3C_2, TiB_2, Sc_2CO) revealed that the grain size (extremely fine:<0,4 #mu#m) improves the properties more than any change in chemical composition. The grinding process for hard machining the test samples with best quality has been developped with the same joint project at the IFW Hannover. (orig.)SIGLEAvailable from TIB Hannover: F99B25+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman