潤滑劑與製程參數對Al-0.8Mg-0.5Si鋁合金擠壓鑄件的影響

Effects of lubricant and processing parameters in squeeze casting Al-0.8Mg-0.5Si aluminum alloy

黃永森(Yung-Sen Huang)

指導教授 ： 施登士

國立中央大學/工學院/機械工程學系/碩士(2007年)

摘要

本篇研究目的在討論不同的(潤滑劑、澆鑄溫度)製程參數下，利用擠壓鑄造方式得到Al- X Mg-Y Si(X：0.82~0.88wt%；Y：0.55~0.57wt%)鋁合金鑄件，並討論鑄件中微孔/介在物數目和氧化膜對於拉伸性質與疲勞性質的影響。
在拉伸性質方面，試棒在相同應變速率下，試棒中反應膜面積率越多對試棒的拉伸強度及延伸率的影響越嚴重。
在疲勞性質方面，分析兩種高低反覆應力的破壞模式與鑄件微結構改變的關係，並將反應膜面積率、介在物顆粒與疲勞曲線結合討論鑄件中微孔/介在物和氧化膜對疲勞壽命的影響。實驗結果顯示，存在於試棒表面附近的反應膜對疲勞壽命的影響較介在物顆粒的影響效果更為顯著。
擠壓鑄造Al-(0.82~0.88)Mg-(0.56~0.57)Si合金在使用石墨粉末作為潤滑劑與Die casting水性金屬模離型劑，在擠壓壓力為60MPa，澆鑄溫度750℃和模具溫度180~200℃的製程參數下可獲得較佳的機械性質。

關鍵字

Al-Mg-Si鋁合金 ； 擠壓鑄造 ； 反應膜 ； 微孔/介在物

並列摘要

This study focus on the investigating of the effect of pore/particle counts and reaction films on the tensile & fatigue properties of squeeze casting. The material used in this study were Al-X Mg-Y Si(X：0.82~0.88wt%；Y：0.55~0.57wt%) alloys.
The tensile test was performed at the same strain rate(0.67mm/min). The reaction film plays an important role on the ultimate tensile strength and the elongation of samples. The ultimate tensile strength and elongation were decreased with the increasing the area fraction of reaction films trapped in castings.
For fatigue life cycles test, when the reaction film resides at the area near the surface of specimen readily to initiate crack, and the fatigue life cycles were greatly deteriorated.
The processing parameters for higher quality squeezed Al-X Mg-Y Si alloys pouring as temperature of 750℃,mold temperature 180~200℃ and squeeze pressure 60MPa,and using water base lubricant added with Graphite powder alory with die casting hydrophilic releasing agent.

並列關鍵字

Al-Mg-Si aluminum alloys ； squeeze cast ； reaction film ； pore/particle

參考文獻

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