本實驗利用擠壓鑄造法製作鋁基複合材料，基地為鋁鋅鎂合金，強化相為
氧化鋁纖維。製作過程中改變合金中的鎂含量(1.23wt%~2.97 wt%)，以探
討鎂元素對複合材料時效行為的影響。DSC分析結果顯示，氧化鋁纖維會
抑制基地強化相，η'相的析出，使得基地時效硬度降低，並提早析出完
全。複合材料基地中，添加鎂元素可使複合材料基地中，η'相的析出量
增加，並延長其析出完全的時間。複合材料基地的最大微硬度，也隨著鎂
含量的增加而上昇。鋁鋅鎂合金與複合材料的耐磨耗實驗，其結果顯示，
複合材料的耐磨耗性較鋁鋅鎂合金為優。但在磨耗圈數增加時，由於複合
材料的磨屑中，含有硬度較高的氧化鋁纖維，反而造成複合材料的磨耗量
增高。

The effect of adding magnesium on the aging behavior of Al-Zn-
Mg alloy reinforced with aluminum (Al2O3) was studied using
differential scanning calorimeter(DSC) technique, hardness
measurement. The magnesium contents were varied from 1.23wt% to
2.97wt%. The addition of magnesium was found to increase the
amount of η'-phase formation in composites. The formation
enthalpy of composites was 0.932cal/g and 1.375cal/g for lower
magne- sium content(1.23wt%) and higher magnesium content(2.97
wt%) respectively. The time needed for the saturation of
precipiat- ing in the composites changed from 12 hr to 48hr as
the magne- sium content increased from 1.23wt% to 2.97wt%. The
maximum hardness occurred in composites with 2.97wt% Mg that
contained a maximum amounts of η'-phase precipitates. The
hardness of the composites was always less than that of monoli-
thic alloys because of alumina fibers caused suppression of η'
formation in composites. Difference of wearability between
composites and Al-Zn-Mg alloy was also performed in this study.
The weight loss decreased with increasing the volume fraction
of alumina and with increasing the magnesium content.