【正文】 鎂合金輪轂真空高壓鑄造技術研究 重慶大學 碩 士學位論文 學生姓名：劉偉召 指導教師：龍思遠 專 業(yè)：材料加工工程 學科門類：工學 重慶大學材料科學與工程學院 二 O 一一 年 五 月 A Study on Vacuum Aided High Pressure Diecasting for Mg Wheel A Thesis Submitted to Chongqing University in Partial Fulfillment of the Requirement for the Degree of Master of Engineering by Liu Weizhao Supervisor by Prof. Long Siyuan Major: Material Processing Engineering College of Material Science and Engineering of Chongqing University, Chongqing, China May, 20xx 中文摘要 I 摘 要 輪轂作為 汽車、摩托車的慣性運動 部件，其輕量化 將顯著降低 行駛能耗和排放，推動 鎂合金在輪轂上的應用 ，是 車輛 通過 輕量化 實現(xiàn)節(jié)能減排的最有效 途徑 。 但是，目前汽車、 摩托車 鋁合金輪轂 生產 主要采用重力鑄造或 低壓鑄造工藝，其 生產效率 低 、缺乏鎂合金致密成形所需 的 高壓補縮能力， 不能 用于鎂合金輪轂的高效率、高收得率 工業(yè) 生產。因此，開發(fā)基于市場保有量巨大的冷室高壓壓鑄機、適合鎂合金鑄造工藝特性的新型高壓鑄造方法，是推動鎂合金在輪轂產品上規(guī)模應用的關鍵。 本課題以 新感覺 出口 摩托車 輪轂為 對象， 通過新型高壓鑄造工藝研發(fā) 、輪轂材料替代 設計 及 工藝 結構優(yōu)化， 鑄造工藝及 模具優(yōu)化設計 、樣件生產及 工藝品質與服役性能 檢測，形成能夠用于工業(yè)生產的輪轂 真空輔助 高壓鑄造技術，為輪轂在 存量 臥式 冷室 壓鑄機上 的規(guī)?；?生產提供指導。 本文 取得的 主要成果如下： ① 根據(jù)輪轂 工藝結構特征，提出了基于臥式冷室壓鑄機、能同時對 輪輻兩端熱節(jié)進行凝固收縮補償?shù)妮嗇?真空高壓 鑄造新方法，并申請了發(fā)明專利； ② 完成了新感覺鋁合金輪轂的 三維造型 和服役狀態(tài)有 限元應力分析 ，逆向確定了原輪轂設計的疲勞準則； ③ 根據(jù) 鎂合金 輪轂的機械性能， 對 輪轂產品的服役及工藝結構進行再設 計 ，在滿足結構工藝要求的前提下，使 鎂合金輪轂 服役 應力 變化 更加緩和， 安全服役系數(shù) 從 提高到 ，實現(xiàn)減重 38%。 ④ 用 數(shù)值模擬 軟件對鎂合金輪轂的鑄造工藝過程就行了仿真分析，優(yōu)化了澆注排溢系統(tǒng) 和鑄造工藝參數(shù)組合。確定的 最佳工藝參數(shù)組合 為： 澆注溫度 680℃ ，模具預熱溫度 250℃ ，壓射速度 ，保壓壓力 60MPa； 單只輪轂生產周期 為40~50s，工藝收得率 為 73%；在此 基礎上 完成 了輪轂的成型模具 設計 ，并和合作企業(yè)一起完成了模具的 制造 、 調試 和實驗性生產 ； ⑤ 在合作企業(yè)進行了 鎂合金輪轂 的 真空輔 助 高 壓鑄造實驗性 生產， 對樣件的工藝品質 進行的工業(yè)和實驗室檢測表明，產品的內部和外在質量均滿足設計要求； ⑥ 輪轂樣件通過了按國家相關標準進行的徑向疲勞試驗、沖擊試驗、旋轉彎曲疲勞試驗、扭轉疲勞試驗等臺架試驗檢測。 關 鍵詞 ：鎂合金， 摩托車 輪轂，壓鑄， 有限元分析， 工藝 模擬 重慶大學碩士學位論文 II 英文摘要 III Abstract The wheels are the most massive inertia moving parts of the road vehicle. Their weight saving will reduce the energy consumption and emissions of the vehicle most effectively. Therefore, it is of economically, technically and environmentally importance to promote the application of magnesium alloy on the wheels. However, the main stream wheels are mainly made of Al alloy and mainly produced by gravity diecasting or lowpressure diecasting characterized by their low productivity and lack of high pressure necessary for shrinkage feeding of magnesium, which, in turn, unable to produce quality Mg wheels with an acceptable productivity. Therefore, the key to promote mercial application of magnesium wheels is to develop a new high pressure diecasting technique that is not only suit to the casting properties of magnesium alloy, but also to meet the requirements for quality Mg wheels at a petitive productivity on coldchamber die casting machine. In the present study, aimed to produce Mg wheels for XGJAO export motorcycle, the structure of the original Al wheel was redesigned, a new vacuum aided high pressure diecasting technique was developed, the cast mold were designed and the processing parameters were optimized, and a trial casting unit consisting of a modified coldchamber diecasting machine and a vacuum system were prepared. Then, prototype Mg wheel were produced by trial production, followed by processing quality and service property testing. The main achievements of the present study are as follows: ① According to the structural characteristics of the wheel, a vacuum aided high pressure die casting technique capable of feeding the solidification shrinkage on both ends of the spokes was invented, followed by patent application。 ② Acplished 3D modeling of XGJAO Al wheel and its service condition finite elemental analysis. Then, the fatigue design criteria was reversely determined。 ③ Based on the mechanical properties of the Mg alloy for wheels, the structure of the wheel was redesigned with consideration of its castability. With the optimized structural design, the service safety factor is increased from of the original Al wheel to , acpanied by a weight saving of 38%。 ④ With numerical simulation software, the casting processing of the Mg wheel was simulated and optimized. With the optimized processing parameters of “680℃ 重慶大學碩士學位論文 IV melt pouring temperature, 250℃ mold preheating, , 60MPa holding pressure”, a wheel can be produced in 40~50s with a melt utilization rate of 73%. Based on the above results, the casting equipments and mold were prepared. ⑤ Prototype wheels were produced on the vacuum aided high pressure die casting unit. The following processing quality inspection evidenced that the internal and external quality of the wheel products meet the requirements of the original design。 ⑥ The prototype wheels passed the bench tests, such as radial fatigue testing, impact testing, rotating bending fatigue testing and torsion fatigue testing, in accordance with the relative national standards. Keywords: Magnesium alloy, Motorcycle wheel, Die casting, FEM analysis, Processing simulation 目 錄 V 目 錄 中文摘要 ............................................................................................................................ I 英文摘要 ..........................................................................................................................III 1 緒 論 ........................................................................................................................... 1 前言 .......................................................................................................................... 1 交通工具輕量化與鎂合金在交通工具上的應用 ..................................................... 2 輪轂輕量化的優(yōu)點及鎂合金在輪轂上的應用現(xiàn)狀 ................................................. 3 鎂合金輪轂的研究現(xiàn)狀 .............................................................................................. 4 鋁合金輪轂的生產技術現(xiàn)狀 ................................................................................. 4 鎂合金輪轂的成形技術現(xiàn)狀 ...............