冷压过程中Co粉结构变化.pdfVIP

Cryst. Res. Technol. 34 1999 8 1005–1010 B. A. MARINKOVIC, B. D. STOJANOVIC, Z. RAKOCEVIC*, A. KREMENOVIC**, S. DURIC** Center for Multidisciplinary Studies University of Belgrade, Joint Laboratory for Advanced Materials of SASA * Institute for Nuclear Sciences “Vinca”, Belgrade ** Faculty of Mining and Geology, Crystallographic Laboratory, University of Belgrade The Microstructural Changes of Cobalt Powder in Consequence of Cold Pressing Process The application of pressure as a technique for obtaining dense and mechanically strengthen materials has been investigated from the structural aspect by the use of X-Ray Powder Diffraction (XRPD) and Scanning Tunneling Microscopy (STM). Keywords: cobalt, pressure, stacking faults 1. Introduction Cold pressing, also known as cold sintering (GUTMANAS et al. 1984), is a metallurgical process for the production of materials with high mechanical properties. It has been established that the lower temperatures of consolidation may provide more possibilities for the utilization of properties of powders obtained by rapid solidification technologies (COHEN; GUTMANAS). Opposite to, conventional or hot sintering, that is carried out at relatively high temperatures (TTm /2, when Tm is the temperature of the melting point), the term cold sintering indicates dominant influence of pressing pressure at room temperature. It has been shown that the plastic flow of powder particles influenced by high pressure, as one of the main mechanisms of powder consolidation during cold pressing, leads to high density and physical contacts. Also, the bonding of particles,