摩擦攪拌銲接技術應用於鎂合金AZ31B-H24接合性質之研究
No Thumbnail Available
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
鎂合金的輕量化、高比剛性及比強度、密度低與吸震性佳等特性，近年來被廣泛應用在3C產業及車輛材料上。 鎂合金之摩擦攪拌銲接為低變形、低成本、無污染的固態接合製程，是嶄新的製造技術。
本研究針對3 mm之AZ31B-H24鎂合金板材進行摩擦攪拌銲接，採用自行設計製造的工具頭，配合固定式夾具作定位及夾持，進行各種不同型態的參數組合，包括攪拌桿傾斜角度、工具頭轉速及銲接進給速率、凸銷下壓深度。透過熱電偶作溫度紀錄，ANSYS 軟體執行溫度分佈解析，得到近似函數來估測銲道溫度；並進行金相觀察、硬度、拉伸等機械性質探討。
實驗結果發現，鎂合金AZ31B - H24摩擦攪拌銲接可接合的參數條件相當廣泛，但改變參數條件能獲得不同的機械性質，在前進傾斜角2度及導引端下壓深度0.08 mm條件下，當摩擦攪拌銲接參數 設定在2和10之間， 輸入熱為230 ℃到290 ℃左右，且銲道內無缺陷，攪拌區形成等軸細晶，拉伸斷裂位置在攪拌區與熱影響區交界處，接合效率介於78.75到87.11 %；其中以 值趨近5.6之銲件迴轉節距適中，銲道內進給邊及退出邊摩擦熱均勻，可得最高抗拉強度值。
Due to their lightweight, high specific stiffness and specific strength, magnesium alloys have been widely used for 3C (Computer, Communication and Consumer Electronics) industries and vehicles recently. Friction stir welding (FSW) is an emerging solid-state and nonpolluting joining process that produces low-distortion and low-cost welds. This study focus on 3-mm AZ31B-H24 plate by FSW, using the tool self-designed and self-made, with cramp fixture located and fixed, proceeding various parameter combination, including stir rod travel angle, tool rotation, traverse speeds and plunge depth. Through temperature record of thermocouples, distribution of temperature analysis executed by ANSYS software, obtain approximating function estimate temperature. Microstructures of the welds will be examined using optical microscopy (OM) and scanning electron microscopy (SEM). Tensile properties and micro hardness of the welds will be evaluated at room temperature. According to the experimental results, the weldable parameters for AZ31B-H24 plates by FSW are quite board, but modifying parameters have different mechanical property. With travel angle 2∘and leading depth 0.08 mm, when FSW welding parameters between 2 to 10, obtain about 230 ℃ to 290 ℃ heat input, and the internal weld pass defect-free, fine equiaxial grain formed in stir zone, and break in boundary between stir zone and HAZ. The efficiency of joint is about 78.75% to 87.11%. Especially when approaching 5.6 with proper revolution pitch, advancing side and retreating side of weld pass have uniform frictional heating, the tensile strength is highest.
Due to their lightweight, high specific stiffness and specific strength, magnesium alloys have been widely used for 3C (Computer, Communication and Consumer Electronics) industries and vehicles recently. Friction stir welding (FSW) is an emerging solid-state and nonpolluting joining process that produces low-distortion and low-cost welds. This study focus on 3-mm AZ31B-H24 plate by FSW, using the tool self-designed and self-made, with cramp fixture located and fixed, proceeding various parameter combination, including stir rod travel angle, tool rotation, traverse speeds and plunge depth. Through temperature record of thermocouples, distribution of temperature analysis executed by ANSYS software, obtain approximating function estimate temperature. Microstructures of the welds will be examined using optical microscopy (OM) and scanning electron microscopy (SEM). Tensile properties and micro hardness of the welds will be evaluated at room temperature. According to the experimental results, the weldable parameters for AZ31B-H24 plates by FSW are quite board, but modifying parameters have different mechanical property. With travel angle 2∘and leading depth 0.08 mm, when FSW welding parameters between 2 to 10, obtain about 230 ℃ to 290 ℃ heat input, and the internal weld pass defect-free, fine equiaxial grain formed in stir zone, and break in boundary between stir zone and HAZ. The efficiency of joint is about 78.75% to 87.11%. Especially when approaching 5.6 with proper revolution pitch, advancing side and retreating side of weld pass have uniform frictional heating, the tensile strength is highest.
Description
Keywords
摩擦攪拌銲接, 鎂合金, 摩擦攪拌參數, 抗拉強度, 摩擦熱, FSW, Magnesium Alloy, FSW welding parameter, tensile strength, frictional heating