臺灣博碩士論文加值系統

鑄造用鋁合金所成型的物件有著良好的機械性質如強度、硬度...等且有著輕量化的特性，但由於其合金成份中含有矽、銅、鎂等元素所產生的化合物使得鑄件延展性不佳，因此多數的鑄件普遍被認為不能應用在較高破壞強度的應用上，大部分皆是應用於外觀件上，目前單純倚靠熱處理無法有效增強鑄件之強度及延展性質。
本研究以A356鑄造用鋁合金為基礎材料，重力鑄造時分別添加0wt%-1wt%錳、0 wt%-5 wt%鋅、0wt%-0.1wt%鍶三種化學元素的母材於溶湯中，製作成錠塊後以重複熱處理進行性質改變，重複熱處理條件為連續兩次520°C高溫固溶處理，水淬後再進行170°C時效處理720分鐘。經過熱處理後的鋁合金錠塊分作兩個方向研究，第一個為機械性質測試:以3軸高速加工機製作成拉伸試片及硬度試片，測試其抗拉強度、降伏強度、延展性及硬度；第二個為微觀組織觀測，以拋光設備與凱勒浸蝕劑將合金微觀組織顯示於高倍數顯微鏡下，觀察其金屬間化合物的變化。
從實驗結果中發現，以T6時間6小時搭配添加錳0.2wt%、鋅5wt%及鍶0.03wt%鑄造出來的鑄件為最佳，鑄件強度可達278.6MPa、延展性可達3.3%、硬度可達104.5HBW，相對A356-T61合金相比，強度可提升約9%、硬度可提升23%，延展性下降約34%。

Cast aluminum alloy has good mechanical properties such as strength, hardness…etc, and has the characteristics of light weight. But its components contain with silicon, copper, magnesium and other elements that produced into the compound makes casting ductility poor. Therefore, most of the castings are generally considered that cannot be applied in the application of high breakdown strength, majority application are applied in the appearance of the pieces. The current method to increase the strength of castings is using heat treatment, but it’s not really effectively to enhance the strength and ductility of the casting.
In this research used A356 to be the base material. The 0wt%-1wt% of manganese, 0wt%-5wt% of zinc and 0wt%-0.1wt% of strontium add into melt while casting. After manufacturing into ingots, treat with multiple heat treatment to increase the mechanical properties including tensile property, hardness and ductility. The condition of heat treatment included solution treatment with 520°C in twice continuously, quenching before ageing treatment with 170°C, 720 minutes. Two ways of studying after heat treatment, one is about the mechanical properties testing including tensile properties, hardness and ductility. Another is about the microstructure observation. Using the polishing equipment and keller’s reagent to displayed the microstructure of alloy under high magnification microscope.
From the experimental results, it is found that the casting with the addition of 0.2wt% of manganese, 5wt% of zinc and 0.03wt% of strontium for 6 hours in T6 heat treatment is the best with the strength of 278.6MPa and the ductility of 3.27%. The hardness can be up to 104.5HBW, the strength can be increased by about 9%, the hardness can be increased by 23% and the ductility by about 34% compared with the A356-T61 alloy.

摘要.........................................I
Abstract...................................II
目錄........................................III
圖目錄......................................V
表目錄......................................VII
第一章 緒論..................................1
1.1 導論.....................................1
1.2 研究動機.................................1
1.3 論文結構.................................2
第二章 文獻回顧...............................3
2.1 鋁合金特性................................3
2.2 鑄造鋁-矽合金.............................4
2.2.1 鋁-矽-鎂合金之機械性質...................4
2.2.2 鋁-矽-鎂合金之微觀組織...................5
2.2.3 添加元素對合金之影響.....................6
2.3 鋁合金重力鑄造.............................9
2.3.1 重力鑄造及其材料.........................9
2.3.2 重力鑄造之優缺點.........................10
2.4 A356鋁合金固溶與時效之熱處理...............11
2.4.1 鋁合金之析出硬化.........................11
2.4.2 固溶處理(Solution Treatment)............11
2.4.3 淬火(Quenching).........................11
2.4.4 時效處理(Aging Treatment)...............11
2.4.5 連續固溶處理.............................12
2.5 鑄件缺陷之檢測方式.........................14
2.5.1 非破壞性檢測............................14
2.5.2 破壞性檢測..............................19
2.5.3 總結....................................19
2.6 研究目標..................................20
第三章 實驗方法及步驟..........................21
3.1 實驗方法流程...............................21
3.1.1 田口實驗設計方法.........................22
3.1.2 合金熔煉與重力鑄造.......................23
3.1.3 拉伸試驗................................24
3.1.4 硬度試驗................................25
3.1.5 微觀組織分析.............................25
3.1.6 氣孔分析.................................26
3.2 實驗器材及設備.............................27
3.2.1 合金材料................................27
3.2.2 高週波熔解爐.............................27
3.2.3 高溫爐..................................28
3.2.4 CNC銑床加工機............................29
3.2.5 手動研磨拋光機...........................30
3.2.6 超音波洗淨機.............................31
3.2.7 光學顯微鏡(Optical Micrographs,OM).......32
3.2.8 硬度試驗機...............................33
3.2.9 萬能拉伸試驗機...........................33
3.5.10 高精度電子天平..........................35
第四章 結果與討論...............................36
4.1 硬度量測之實驗結果..........................36
4.1.1 硬度檢測.................................36
4.1.2 熱處理前硬度L9(34)輔助表..................37
4.1.3 熱處理後硬度L9(34)輔助表..................38
4.1.4 不同深度硬度檢測..........................39
4.2 拉伸性質量測之實驗結果.......................40
4.2.1 抗拉強度檢測..............................40
4.2.2 熱處理前抗拉強度L9(34)輔助表...............41
4.2.3 熱處理後抗拉強度L9(34)輔助表...............42
4.2.3 延展性檢測................................43
4.2.4 熱處理前延展性L9(34)輔助表.................44
4.2.5 熱處理後延展性L9(34)輔助表.................45
4.2.6 確認組實驗結果............................46
4.3 金相組織分析之實驗結果.......................46
4.4 孔隙率量測之實驗結果.........................49
4.4.1 空氣中重量量測............................49
4.4.2 實際密度量測..............................49
4.4.3 孔隙率計算................................50
第五章 結論與未來展望............................51
5.1 結論........................................51
5.2 未來展望....................................51
參考文獻........................................52

[1] 莊水旺，2013，智慧型壓鑄模具生產技術(Fabrication Technology of Intelligent Die Casting Molds)，五南書局，臺灣。
[2] 蔡宇洲，2006，微量La與Ce稀土元素對A356(Al-7Si-0.35Mg)鑄鋁合金之影響，碩士論文，國立中央大學，桃園，臺灣。
[3] 金重勳，2005，機械材料，復文書局，臺灣。
[4] Choong Do Lee, 2007, “Effects of microporosity on tensile properties of A356 aluminum alloy”, Materials Science and Engineering A 464, 249–254.
[5] A.K. Dey, P. Poddar, K.K. Singh and K.L. Sahoo, 2006, “Mechanical and wear properties of rheocast and conventional gravity die cast A356 alloy”, Materials Science and Engineering A 435–436, 521–529.
[6] Chang Yeol Jeong, Chang-Seog Kang and Jae-Ik Cho, 2007, “Effect of Alloying Elements on Mechanical Properties for A356 Casting Alloy”, Advanced Materials Research Vols. 26-28, pp. 111-114.
[7] Sheng-Long Lee, Yin-Chun Cheng, Wen-Chi Chen, Cheng-Kuo Lee and Ah-Hung Tan, 2012, “Effects of strontium and heat treatment on the wear-corrosion property of Al-7Si-0.3Mg alloy”, Materials Chemistry and Physics 135, 503-509.
[8] Man Zhu, Zengyun Jian, Gencang Yang and Yaohe Zhou, 2011, ”Effects of T6 heat treatment on the microstructure, tensile properties, and fracture behavior of the modified A356 alloys”, Materials and Design 36, 243–249.
[9] M.Tocci, R. Donnini , G. Angella and A. Pola, 2017, “Effect of Cr and Mn addition and heat treatment on AlSi3Mg casting alloy”, Materials Characterization 123, 75–82.
[10] Hyun You Kim, Tea Young Park, Sang Won Han and Hyuck Mo Lee, 2006, “Effects of Mn on the crystal structure of a-Al(Mn,Fe)Si particles in A356 alloys”, Journal of Crystal Growth 291, 207–211.
[11] Yasin Alemdag and Murat Beder, 2014, “Microstructural, mechanical and tribological properties of Al–7Si–(0–5)Zn alloys”, Materials and Design 63, 159–167.
[12] Sang-Soo Shina, Eok-Soo Kima, Gil-Yong Yeomb and Jae-Chul Lee, 2011, “Modification effect of Sr on the microstructures and mechanical properties of Al–10.5Si–2.0Cu recycled alloy for die casting”, Materials Science and Engineering A 532, 151– 157.
[13] Paulson Varghese, Febin Joseph, Merrin John Varkey, Don Dominic, M. Pooja, V. Vijeesh and K. G. Samuel, 2016, “The Effect of Strontium Modification on T6 Heat Treatment Parameters, Microstructure and Hardness of Aluminum SiliconA356 Alloy”, Journal of Materials and Metallurgical Engineering Volume 1, Issue 2.
[14] 劉國雄，林樹均，李勝隆，鄭晃忠，葉均蔚，2007，機械材料學，全華圖書，臺灣。
[15] 郭冠鴻，2008，La與Ce稀土元素對A356鋁合金微結構及機械性質之影響，碩士論文，遠東科技大學，台南，臺灣。
[16] 金重勳，2001，熱處理，復文書局，臺灣。
[17] K.T. Akhil, SanjiviArul and R.Sellamuthu,2014 , ”The Effect of Heat Treatment and Aging Process on Microstructure and Mechanical Properties of A356 Aluminium Alloy Sections in Casting”, Pro Eng 97, 1676-1682.
[18] I.A. Luna, H.M. Molinar, M.J.C. Roma´n, J.C.E. Bocardo and M.H. Trejo, 2013, “Improvement of the tensile properties of an Al–Si–Cu–Mg aluminum industrial alloy by using multi stage solution heat treatments”, Materials Science & Engineering A 561, 1–6.
[19] S. Menargues, E. Martín, M.T. Baile and J.A. Picas, 2014, “New short T6 heat treatments for aluminium silicon alloys obtained by semisolid forming”, Materials Science & Engineering A621, 236–242.
 
[20] D.L. Zhang, L.H. Zheng and D.H. StJohn, 2002, “Effect of a short solution treatment time on microstructure and mechanical properties of modified Al–7wt.%Si–0.3wt.%Mg alloy”, Journal of Light Metals 2, 27–36.
[21] C. E. Mobley, 1991, “Comparison of Method for Characterizing Porosity in Die Castings”, Department of Materials Science and Engineering.
[22] J.P. Weiler, 2005, “Relationship between internal porosity and fracture strength of die-cast magnesium AM60B alloy”, Materials Science and Engineering A.