有關汽車熱交換器用3003鋁合金擠製成形性及硬銲特性之研究

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Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/2744

Title:	有關汽車熱交換器用3003鋁合金擠製成形性及硬銲特性之研究
Authors:	蔡政廷;Cheng-Ting Tsai
Contributors:	機械工程研究所
Keywords:	硬銲;擠型;3003鋁合金;分散相;brazing;extrusion;3003 aluminum alloy;dispersoid
Date:	2006-07-07
Issue Date:	2009-09-21 11:54:32 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	第一章緒論主要描述研究背景，鋁合金之前景及其優點，並將相關的理論基礎及論文回顧做一個統整。第二章為本文，主要分為四個部份，第一個部份為前言，介紹本篇論文進行AA3003鋁合金於鋁擠型加工之研究動機。第二個部份主要是介紹論文的實驗流程與實驗手法。第三個部份為結果與討論，探討AA3003鋁合金施以不同均質化條件所形成不同之微結構型態，對於擠製加工與硬銲處理後之機械性質影響，將實驗所得的結果結合理論作ㄧ個詳盡的說明。第四個部份為結論，將實驗結果，歸納重點整理。 AA3003鋁合金施以不同均質化處理，分散相的析出行為亦有所不同。460℃x9h低溫均質化處理會析出緻密的分散相粒子；而有經過600℃x9h過程的均質化處理，分散相粒子皆較為稀疏。低溫均質化傾向析出灰色的Al6(Mn,Fe)粒子，且形態複雜；高溫均質化則傾向析出黑色的α- Al12(Mn,Fe)3Si粒子，多數為圓形粒子。隨著均質化的溫度提升和持溫時間加長，灰色的Al6(Mn,Fe)粒子傾向回溶，轉而形成黑色的α- Al12(Mn,Fe)3Si粒子。擠製突破壓力是由均質化後之溶質原子固溶程度與分散相析出狀況所共同競爭決定，當析出粒子較為粗大稀疏時，擠製突破壓力就由固溶程度所主導。然而，若析出粒子細小緻密到一個程度時，固溶度的主導地位將被取代。另外，再結晶會影響擠製後硬度，完成再結晶的部分，其硬度較低，未完成再結晶的部位，其硬度較高。而析出粒子會影響再結晶的形成，析出粒子緻密，會使再結晶困難，析出粒子稀疏，再結晶會較容易。最終硬銲處理後，460℃x9h(條件a)已經完全再結晶，強度降低；600℃x9h→460℃x3h (條件c)可能局部發生二次再結晶，造成硬度大幅下降。綜括四組均質化條件於硬銲後之機械性質，以460℃x9h(條件a)強度最佳，460℃x1h→600℃x9h(條件d)、600℃x9h (條件b)稍弱，而600℃x9h→460℃x3h (條件c)可能有局部發生二次再結晶之現象，造成強度較不穩定。 The precipitation behavior of dispersoids isn’t the same by different homogenization conditions in AA3003 aluminum alloy. It has been found that fine dispersoids form during homogenization at 460℃x9h and lower density of forming dispersoids during homogenization at 600℃x9h. Homogenization at low temperature is inclined to precipitate grey particle Al6(Mn,Fe) and black particle α- Al12(Mn,Fe)3Si at high temperature. To raise homogenization temperature with time, the grey particle Al6(Mn,Fe) tends to solute into matrix and form black particle α- Al12(Mn,Fe)3Si. The extrusion pressure is determined both with the degree of solution and distribution of dispersoids after homogenization. If the density of dispersoid isn’t high enough, solution would play an important role for extrusion pressure. However, the influence of solution will be replaced by dispersoids when distribution of dispersoids is close. The recrystallization will influent strength of material after extrusion. The position where recrystallization have lower strength. The results indicated that condition (a) 460℃x9h homogenization treatment could get the best strength after brazing, the next was the condition (b) and condition (d), and the worst was the condition (c) 600℃x9h→460℃x9h due to happening of secondary recrystallization.
Appears in Collections:	[Graduate Institute of Mechanical Engineering] Electronic Thesis & Dissertation

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