結合灰關聯分析法與田口法於壓鑄製程參數最佳化研究

Optimization of Die Casting Parameters Using Grey Relational Analysis And Taguchi Method

李國華(Kuo-Hua Lee)

指導教授 ： 陳貞光 ； 陳政順 ； 郭金國

國立臺北科技大學/工程學院/材料及資源工程系研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00118

摘要

鎂合金壓鑄產品經常容易發生表面流紋、充填不足、與翹曲等缺陷。這些缺陷和柱塞速度、射出溫度及模具溫度等製程條件有密切關係。且金屬液因高速充填的緣故，所以不容易預測其充填流動狀態。所以常常容易因為溢流井與逃氣道位置設計不當，使得鑄件產生氣孔的缺陷。故本研究使用模流分析軟體Procast做為分析工具，討論金屬液充填流動的狀況及溢流井與逃氣道最佳位置。
在製程改善方面，在工業上往往需考量到多個品質的最佳化。所以本研究針對AZ91D壓鑄鎂合金製程參數，選擇三個控制因子(柱塞速度、射出溫度、模具溫度)，每個因子皆為三水準，目標品質則設定為最小的固相率、壓力差、平均溫度。由田口方法S/N比分析，可以得到單一目標品質的最佳化。再利用灰關聯分析法，同時衡量最佳方案與理想解及負理想解的，經過總灰關聯度的分析，求得一組最佳壓鑄參數A2 B1 C1 ，且其總灰聯度值為最高，故其確實為最佳因子水準組合。此結果表示灰關聯分析法對於多目標壓鑄參數進行分析，確實可求出最佳壓鑄製程參數，並有效減少鑄件缺陷，改善產品的品質。

關鍵字

壓鑄 ； 鎂合金 ； 模流分析 ； 田口方法 ； 灰關聯分析法

並列摘要

Die-casting magnesium alloys are often easily occurred defects as flow mark, insufficient filling, and warp etc. These defects are closely related with parameters of plunger velocity, injection temperature, and temperature of die etc. Due to liquid metal high-speed filling, it is not easy to predict the status of filling. So often easily design overflow and air vent at inappropriate location, making casting generated gas hole. Therefore, this study was the use of mold flow analysis software analysis tools as Procast to discuss filling the flow of liquid metal and the best location of the overflow and the air vent.
On improvement manufacturing process, industry is often considered optimization to the many of quality. Therefore, this study is aimed at AZ91D magnesium alloy die-casting parameters, selected the three control factors (plunger velocity, injection temperature, die temperature), each factor are the three levels, quality goals are set to the smallest solidification, pressure difference, the average temperature. By Taguchi method by S / N ratio analysis, a single target can be the optimization. Using of gray relational analysis method, simultaneously weighs the preferred plan and ideal solution and negative ideal solution characteristic, undergoes the Grey relational analysis, can find a group of best die-casting parameter A2 B1 C1, and its total gray value of the highest degree, so its really for the best combination of factor levels. The results indicated that gray relational analysis method for multi-objective analysis of die-casting parameters can indeed find the best die-casting parameters, and effectively reduce the casting defects and improve product quality.

並列關鍵字

Die casting ； Magnesium alloys ； mold analysis ； Taguchi method ； Grey relational analysis

參考文獻

[4] B.H. Hu, K.K. Tong, X.P. Niu, I Pinwill,“Design and optimisation of runner and gating systems for thedie casting of thin-walled magnesium telecommunication parts through numerical simulation”, Journal of Materials Processing Technology, vol.105, 2000, pp.128-133.

[5] E.M. Gutman, Ya. Unigovski, M. Levkovich,Z. Koren, E. Aghion, M. Dangur, “Influence of technological parameters of permanent mold casting and die casting on creep and strength of Mg alloy AZ91D”,Materials Science and Engineering ,A234-236, 1997, pp.880-883.

[6] Nahed A. El-Mahallawy, Mohamed A. Taha,Engenius Pokora, Friedrich Klein, “On the influence of process variables on the thermal conditions and properties of high pressure die-cast magnesium alloys”, Journal of Materials Processing Technology, vol.73, 1998, pp.125-138.

[7] K.K.S. Tong, B.H. Hu, X.P. Niu, I. Pinwill“Cavity pressure measurement and process monitoring die casting of thin-wallhand-phone component to improve quality ” ,Journal of Materials Processing Technology,vol.127, 2002, pp.238-241.

[20] Ho-Mun Si, Chongdu Cho, Si-Youbg Kwahk, “A hybrid method for casting process simulation by combining FDM and FEM with an efficient data conversion algorithm”, Journal of Materials Processing Technology, 2003, pp.311-321.