Comparative Analysis of Microhardness in Directional Solidified Zn-27wt%Al, Zn-27Wwt%Al + CSi and Zn-27Wwt%Al + Al2O3 Alloys and Composites

ALICIA ESTHER ARES; CARLOS ENRIQUE SCHVEZOV

Orlando, Florida, USA

Congreso; 136th Annual Meeting and Exhibition; 2007

The Minerals, Metals & Materials Society.

ZA castings are competing with cast iron, bronze and aluminum because of various propertiesand processing advantages. One particular alloy such as the ZA27 (Zn-27wt%Al) has a higheryield 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 microhardnessvariations as a function of both sample length and sample width of Zn-27wt%Al, Zn-27wt%Al+ CSi, Zn-27wt%Al + Al2O3 directionally solidified which present columnar, equiaxed andcolumnar to equiaxed transition structures. Also, to analyze microhardness variations as afunction of type of composite produced. We noticed that the microhardness values decreasewhen the load increase and reach almost constant values at higher loads. The results indirectionally solidified alloys and composites are compared with those in bulk alloys. We observed that bulk alloys have greater microhardness values than those directionally solidified.