COMPARATIVE ANALYSIS OF MICROHARDNESS IN DIRECTIONAL SOLIDIFIED Zn-27wt%Al, Zn-27wt%Al + CSi AND Zn-27wt%Al + AL2O3 ALLOYS AND COMPOSITES

ALICIA ESTHER ARES; CARLOS ENRIQUE SCHVEZOV

INTERNATIONAL FOUNDRY RESEARCH/GIESSEREIFORSCHUNG

VDG GERMAN FOUNDRYMEN´S ASSOCIATION - Michael Franken M. A. (chief editor)

Lugar: Düsseldorf, Germany; Año: 2008 vol. 60 p. 6 - 13

0046-5933

ZA castings are competing with cast iron, bronze and aluminum because of various properties and processing advantages. One particular alloy such as the ZA27 (Zn-27 wt % Al) has a higher yield stress than other zinc alloys and better friction properties than brass at low velocities and dry contact between materials. The main objective of this paper is to analyze microhardness variations as a function of both sample length and sample width of Zn-27 wt % Al, Zn-27 wt % Al + CSi (p), Zn-27 wt % Al + Al2O3 (p) directionally solidified which present columnar, equiaxed and columnar to equiaxed transition structures. Also, to analyze microhardness variations as a function of type of composite produced. We noticed that the microhardness values decrease when the load increase and reach almost constant values at higher loads. The results in directionally solidified alloys and composites are compared with those in bulk alloys. We observed that bulk alloys have greater microhardness values than those directionally solidified.2O3 (p) directionally solidified which present columnar, equiaxed and columnar to equiaxed transition structures. Also, to analyze microhardness variations as a function of type of composite produced. We noticed that the microhardness values decrease when the load increase and reach almost constant values at higher loads. The results in directionally solidified alloys and composites are compared with those in bulk alloys. We observed that bulk alloys have greater microhardness values than those directionally solidified.