鑄/鍛鋁合金的微結構對機械性質的影響

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Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/72658

Title:	鑄/鍛鋁合金的微結構對機械性質的影響
Authors:	魏千竣;Wei, Cian-Jyun
Contributors:	機械工程學系
Keywords:	鑄/鍛;微結構;析出相;機械性質;cast/forge;microstructure;precipitations;mechanical properties
Date:	2016-10-20
Issue Date:	2017-01-23 17:12:43 (UTC+8)
Publisher:	國立中央大學
Abstract:	本研究應用鑄/鍛製程生產不同等級機械性質的鋁合金(高強度與中強度高韌性兩組)，主要合金成份分別為Al-1.2Mg-1.0Si-1.0Cu-0.1Zr合金及Al-8Zn-2.5Mg-1.5Cu-xZr(x=0或0.4)合金。實驗的材料利用高週波爐融煉並澆鑄在Y型金屬膜及圓形冷激模，將Y型鑄件冒口切除得到長型試塊(50 mm×40 mm×102 mm)，將試塊進行均質化退火、鍛造變形(冷鍛或熱鍛)、固溶、淬火及時效處理(T6或T73)，熱處理完成後的試塊車成Gage diameter為9 mm的拉伸試棒做拉伸試驗，分析材料微結構對機械性質的影響。本研究實驗內容包括: (1)利用超音波振盪機震盪出材料的氧化膜，分析氧化膜含量對機械性質的影響。(2)利用影像軟體分析材料基地上的二次相顆粒數及顆粒大小對機械性質的影響。(3)利用背向散射電子(EBSD)分析材料晶粒晶界的高低角度向差。(4)利用掃描式電子顯微鏡(SEM)分析析出相顆粒的成份。(5)利用穿透式電子顯微鏡(TEM)觀察材料的微結構與析出相的型態，並藉由X光繞射儀(XRD)分析析出相的組成元素。實驗結果顯示，材料中的介在物顆粒大於40μm或有介在物團聚會影響材料的延伸率。當Al-Mg-Zn-Cu合金中添加高Zr含量，固溶後AlZr相在基地的冷卻速度慢，會形成固液相共存的包晶反應。最後本實驗利用TEM觀察並分析兩組鑄鍛鋁合金時效處理後基地上析出相的型態，並且探討不同析出相對材料機械性質的影響。 ;In this study, different grades of mechanical properties of Aluminum alloys were produced by the cast/forging process, which is mainly composed of Al-1.2Mg-1.0Si-1.0Cu-0.1Zr alloy and Al-8Zn-2.5Mg-1.5Cu-xZr(x=0 or 0.4%) alloy.The material of the experiment was melted using a high-frequency furnace and pouring solution to the Y-block mold and circular chill mold. Remove the Y-Blocks casting riser to obtain long test blocks (50 mm×40 mm×102 mm). Long test blocks were then subject to homogenization annealing、forging、solid solution、quench and aging(T6 or T73). Then, long test blocks turn into the tensile bars of 9mm gage diameter to do the tensile test. Finally, the microstructure of the materials on the mechanical properties were analyzed. The purpose of the study includes: (1) Observation the oxide film area fraction of the chill was conducted by ultrasonic cleaner. (2) The number of particles and the particle size on the base were calculated from the image analysis software. (3) Using EBSD to analyze the material grain angle different of the grain boundary. (4) Using SEM to analyze the composition of the precipitated particles. (5) Using X-ray to observe the microstructure of the materials and the precipitations morphology, then analyzed of the composition of precipitations phase elemant. The result of experiment showed that if the interphase particles in the material are greater than 40μm or the interphase is reunited will influence the elongation rate of the material. In the study, when a high level of Zr element is added to the high-strength alloy group, it will decrease the cooling rate of AlZr phase after the solid solution and the the peritectic reaction of solid-liquid phase coexist. Finally, analysis the form of precipitations from two alloy groups in different aging treatment, and then probe into the influence of the precipitations on the mechanical properties of the materials.
Appears in Collections:	[Graduate Institute of Mechanical Engineering] Electronic Thesis & Dissertation

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