鋁基金屬複合材料活塞鍛造成形特性分析與模具設計

Formability Analysis and Die Design for Forging an Aluminum-Based Metal Matrix Piston

黃士庭(Shih-Ting Huang)

指導教授 ： 陳復國

國立臺灣大學/工學院/機械工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.00271

摘要

近年來，鍛品輕量化已成為產學研探討的主要課題之一，雖然鋁基複合材料非常適合製作輕量化且具高強度之產品，然相關產品的成形方法又是鋁基複合材料發展之關鍵因素，因此本研究針對鋁基金屬複合材料A6061/Al2O3之鍛造成形進行研究，並以活塞造型做為研究載具，且使用有限元素法模擬分析來探討鍛造製程參數對成形的影響，同時針對鋁基金屬複合材料A6061/Al2O3之機械性質作深入探討。
在研究方法上，首先選擇具有代表性之活塞載具，利用電腦輔助工程分析(Computer-Aided Engineering，CAE)模擬成形過程中材料之流動方式、特徵造型及鍛造負荷等為指標，探討不同Al2O3含量下之鍛造溫度、鍛造速度與不同潤滑劑等製程參數對材料流動的影響，並與常用於活塞材料之A2618鋁合金比較兩者成形差異性與鍛後材料硬度。本研究同時探討Al2O3於鍛造製程中之顆粒流動情形以及整體材料之流動模式，然後利用CAE分析出解決問題方法。
本研究運用DEFORM-3D有限元素分析軟體作為模擬分析工具，且經由圓柱壓縮實驗取得材料更完整之應力-應變曲線，再以活塞造型作為研究載具，探討鋁基金屬複合材料A6061/Al2O3之成形性。由模擬分析發現鋁基複合材料A6061/Al2O3於活塞鍛造成形過程中，容易發生未填滿之缺陷，而探討產生缺陷的主要原因為材料於成形中，由側向溢出導致模穴未填滿的現象了解缺陷原因後，藉由模具上下模設計溢料槽，抑制材料向外流動，最後經由溢料槽之設計，模穴之未填滿獲得改善。為了驗證分析的正確性，本研究從事實際之活塞鍛造成形實驗，經由實驗驗證材料之流動情形、成形力及型材外形，實驗結果證明了有限元素分析軟體之準確性且歸納出一套設計準則。

關鍵字

鋁基金屬複合材料 ； A6061/Al2O3 ； 活塞鍛造成形 ； 高溫性質 ； DEFORM軟體

並列摘要

Due to its high specific strength and light weight, aluminum-based metal matrix composite (AL/MMC) attracts much attention from the industry for manufacturing the high strength structural components. Thus the forming method of relevant products is the key technology in the development of AL/MMC. Among the manufacturing processes for AL/MMC products, the forging process has much potential because of its competitive productivity and performance in the effective production of components with complex shapes. In the present study, the forging formability of an A6061/Al2O3 MMC piston was examined. The commercial code DEFORM-3D was employed to perform the forging simulations and the material properties of A6061/Al2O3 at elevated temperatures obtained from the compression tests were used as the input data for the finite element simulations. The influence of forging process parameters on the formation of A6061/Al2O3 piston was studied first. This study took material, characteristics modeling, and forging load of material during formation as indicators, investigating the influence of process parameters including forging temperature, forging speed and different lubricants on the material flow when different contents of Al2O3 were adopted.
This study also discusses the flow status of Al2O3 particles during forging process and the flow mode of the whole blank material. The simulation results indicate that insufficient filling would occur during the forging of an A6061/Al2O3 MMC piston. The die cavity was not completely filled due to lateral overflow of material in the forging process. In order to cope with the insufficient filling problem, this study designed one spew groove between punch and bottom die, preventing the material overflow. The actual forging process was implemented and the features of the forged part were compared with the finite element simulation results. The good agreement between the production part and the finite element simulation results in material flow, forging force and appearance of part profiles confirms the validity of the finite element analysis. The sound production part also indicates that a complex shaped component made of A6061/Al2O3 MMC could be formed by the forging process with proper die design at elevated forming temperature.

並列關鍵字

aluminum-based metal matrix composites ； A6061/Al2O3 ； piston ； finite element method

參考文獻

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