A note on the effect of glass reinforcement on the properties of as-cast and heat treated Zn-12Al composite alloy

Zn-12 wt.% aluminum alloy with and without glass reinforcements was prepare d by compocast method. Glass particulate and/or short glass fiber reinforce ments in the range of 5 wt.% were introduced into the vortex created in the molten alloy through an impeller rotated at 600-800 rpm. Specimens from re inforced and unreinforced alloys were heat treated with different aging tim es. Examination of the microstructure was carried out on the as-cast materi als using optical microscopy. SEM microscopy was also used to examine the f racture and wear surfaces. Tensile and wear tests were employed on the as-c ast and heat treated materials at room temperature. Also, tensile tests at 150 degreesC were carried out on the as-cast specimens. The results reveale d that glass reinforcements refined the structure of Zn-12Al On the other h and, the mechanical properties and wear resistance of as-cast and heat trea ted alloys were improved by the addition of reinforcements. In the case of short fiber and particulate, the UTS, YS and elongation show higher values compared to fiber or particulate reinforcement. At elevated temperature, a decrease in tensile properties of both matrix and composite alloys was show n, but the glass reinforcements showed some improvement in the tensile prop erties compared to the Zn-12Al alloy. This improvement was accompanied by a substantial increase in ductility. (C) 2001 Published by Elsevier Science B.V.