- 期刊
提升AG40A鋅合金壓鑄件健全性之探討
Improvement in the Soundness of AG40A Zinc Alloy Die-casting
摘要
本研究主要是運用CAE電腦輔助模擬分析軟體Flow-3D設計AG40A鋅合金衛浴把手壓鑄件之各種不同鑄造方案，包括澆流道、溢流井與排氣道設計，並變化各種熱室壓鑄製程參數條件，及實際開模進行各種方案設計之澆鑄，以探討提升AG40A鋅合金壓鑄件健全性之方法。探討的製程參數主要有熔液澆鑄溫度、模具溫度和鑄造壓力。 研究結果顯示，利用Flow-3D預測AG40A鋅合金衛浴把手壓鑄件產生的缺陷及區域確實與實際壓鑄件所產生的缺陷及位置極為吻合。將模具溫度升至180℃或將澆鑄溫度增至440℃時，衛浴把手鑄件只減少表面冷接流痕，但以400℃澆鑄溫度搭配90 kg/平方公分以上的鑄造壓力時，可使鑄件表面光滑無流痕，且內部氣孔亦可大量地減少。此外，在具有適當溢流井或逃氣道的壓鑄方案設計之下，AG40A鋅合金衛浴把手鑄件內部的孔洞和將表面冷接流痕明顯減少許多，惟仍無法完全消失。 利用Flow-3D模擬分析與設計適合的澆流道系統與溢流井及逃氣道方案時，可使實際AG40A鋅合金把手壓鑄件的孔洞率顯著降低，其健全等級在最差方案時為91.33%，但在最佳方案時可提升至98%。故，改變壓鑄製程參數雖可減少缺陷之產生，惟仍必需再配合適當的澆流道、排氣道與溢流井設計，才能大幅提升AG40A鋅合金壓鑄件的健全性。另外，若將AG40A鋅合金中的鎂含量稍微增加，會使得衛浴把手鑄件表面受到潮溼腐蝕的傾向提高，造成衛浴把手鑄件表面容易裂開而劣化。
並列摘要
The methods concerning how to improve the soundness of AG40A zinc alloy sanitary handle die-castings are the subject of this study. Research approaches include different designs of gating system with or without overflow and air vent along with evaluation of process parameters for hot chamber die casting, which was analyzed by FLOW-3D simulation software. The process parameters studied include pouring temperature of melt, mold temperature and casting pressure. The sanitary handle die-castings produced were compared with CAE simulation results. The results indicate that the defects in AG40A zinc alloy sanitary handle die-castings are similar to those found by FLOW-3D simulation for each gating system design. The flowing mark of cold shut on surface of AG40A zinc alloy sanitary handles can be merely prevented by adopting the casting condition of 180℃ mold temperature or 440℃ pouring temperature. Furthermore, the flowing mark of cold shut on sanitary handle castings will be totally eliminated under the condition of 400℃pouring temperature combined with a casting pressure of over 90 kg/cm^2, and their internal porosities will also be reduced. In addition, the internal porosities in AG40A zinc alloy sanitary handles can be substantially reduced by employing a gating system with suitable overflow or air vent, but they can not be completely eliminated. It is worthy of mentioning that, via FLOW-3D simulation, the soundness rating of AG40A zinc alloy sanitary handles is 91.33% for the unsatisfactory gating system design, but the rating can be improved to about 98% for the optimal design. Moreover, the degree of corrosion on surface of AG40A zinc alloy sanitary handle caused by humidity increases as the magnesium content of AG40A zinc alloy is increased slightly from 0.04% to 0.06%, causing detrimental cracks on the surfaces of handle die-castings.