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題 名 | Al-Si和Al-Si-Cu系合金之流動性研究=A Study on the Fluidity of Al-Si and Al-Si-Cu Alloys |
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作 者 | 胡瑞峰; 潘永寧; | 書刊名 | 鑄工 |
卷 期 | 23:1=92 1997.03[民86.03] |
頁 次 | 頁48-66 |
分類號 | 472.5 |
關鍵詞 | 鋁合金; 流動性; 凝固冷卻曲線; 凝固模式; Aluminum alloys; Fluidity; Thermal analysis; Solidification mode; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究主要係探討Si含量、Cu含量以及一些微量元素添加,如Mg(合金強化元素 )、 Sr (共晶矽調質元素)、 P (初晶矽改良元素)和 Ti (晶粒細化元素)等, 對於 Al-Si 和 Al-Si-Cu 系合金之流動性影響。流動性之測定是採用 Spiral Fluidity Test 方 法。 研究結果顯示 Al-Si 系合金之流動性隨 Si 含量之增加而增加, 在 14 ∼ 16 % Si 時達 到最大值,然後隨 Si 含量之再增加而逐漸降低。對於亞共晶( 5 ∼ 7 % Si )和共晶( 11 ∼ 13 % Si )成分之 Al-Si 系合金而言,經 Ti 細化及 Sr 調質後之流動性較均未處 理者佳。 但對於過共晶( 14 ∼ 20 % Si )成分而言,添加 Ti 和 P 後流動性則較均未 添加者差。 此外, 添加 Mg 元素會增進 Al-Si 系合金之流動性。 又, 熔液之過熱度( superheat )愈高,流動性亦愈佳。A-Si-Cu 系合金之實驗結果與 Al-Si 系合金相似。 本研究實際量測鋁合金之凝固冷卻曲線, 並以電腦輔助冷卻曲線分析( Computer-Aided Cooling Curve Analysis )方法探討合金凝固時所釋放之潛熱以及凝固過程之固相分率變 化情形。實驗結果指出,凝固潛熱隨著 Si 含量之增加而增加,此結果意謂著合金之流動性 亦應隨 Si 含量之增加而增加。但另一方面,當 Si 含量高於共晶成分約( 12.6 %)時, 合金之凝固溫度範圍則隨 Si 含量之增加而增加,此將造成流動性之下降。綜合上述二因素 之影響可以充分解釋流動性之最大值發生在 14 ∼ 16 % Si 之間。此外,微量元素 Sr 和 Mg 均會降低共晶溫度及最終凝固溫度,並延長凝固時間,這些因素均會增進 Al-Si 合金之 流動性。 本研究亦深入分析螺旋流動性鑄件之顯微組織,並提出在各種不同鋁合金成分下之凝固模式 ,以探討其對於流動性之影響。 |
英文摘要 | Research on the fluidity of Al-Si and Al-Si-Cu alloys with various compositions was conducted by using spiral fluidity tests. Roles of Si content, Cu content and the presence of minor elements, i. e., Mg, Sr, P and Ti, were evaluated in this study. The results indicate that the fluidity of Al-Si allcys increases as Si content increases, reaches maxima at 14 ∼ 16 % Si, and then decreases with additional increases in Si content. Al-Si alloys with hypoeutectic and eutectic compositions that have been grain refined and Sr-modified exhibit an improved fluidity of about 20 ∼ 30 % when compared with untreated Al-Si alloys. Furthermore, the introduction of Mg to Sr-modified Al-Si alloys increases alloy fluidity by another 10 %. However, for Al-Si alloys with hypereutectic compositions, P-refined melts have a lower fluidity than do non-refined melts, about 10 ∼ 20 % lower. Al-Si-Cu alloys are similar to Al-Si alloys, but the maximum fluidity values of Al-Si-Cu (2.0 % & 4.5 % ) alloys occur at 14 % Si. In addition, the presence of Cu enhances the fluidity of Al-Si alloys. In this study, the solidification characteristics and the latent heat generated during solidification were thermally determined. The results of thermal analyses correlated well with the fluidity values of Al alloys studied herein. In addition, microstructural analyses of the spiral castings were performed to correlate the solidification modes with the fluidity of Al alloys. |
本系統中英文摘要資訊取自各篇刊載內容。