標題: 鎂元素對鋁鋅鎂基複合材料時效行為影響之研究
Effect of Magnesium on the Aging Behavior of Al-Zn-Mg/Al2O3 Metal Matrix Composites
作者: 周鳴群
Ming-Chun Chou
朝春光
Dr.Chuen-Guang Chao
材料科學與工程學系
關鍵字: 複合材料,時效行為;Composites,Aging Behavior
公開日期: 1993
摘要: 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.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT820159010
http://hdl.handle.net/11536/57685
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