Hardness of aged ZA-27/short glass fibre reinforced composites

Abstract

This present investigation studies the effects of artificial aging on the hardness of cast ZA-27 zinc-aluminium alloy composites containing short glass fibres of diameter 4-6 μm, length 0.4-0.6 mm and contents of 1, 3 and 5% by weight. The age-hardening characteristics of the unreinforced ZA-27 alloy as well as of the glass fibre-reinforced composite materials were determined using hardness measurements. The aging temperatures were 75, 100 and 125°C, respectively and the aging durations were 6, 12 and 18 h, respectively. The results show that for any particular glass fibres content and aging temperature, hardness seems to increase monotonically with aging time, although it probably tends towards an asymptotic value. For the unaged composites, glass fibre content plays a significant role in determining their hardness values, whereas for all the aged composites, their hardness values are not so dependent on glass fibre content. © 1998 Elsevier Science Ltd. All rights reserved.