微量元素Cr、Mn對Al-Mg-Si合金之微結構及機械性質的影響

Effect of trace Cr and Mn addition on microstructure and mechanical properties of Al-Mg-Si alloys

吳佳鴻(Jia-hong Wu)

指導教授 ： 李雄

國立中央大學/工學院/機械工程學系/碩士(2012年)

摘要

本研究針對Al-Mg-Si 6061鋁合金添加微量元素Cr、Mn進行探討，所設計之三種合金6061、6061+Cr及6061+Mn鋁合金藉由熔煉爐鑄造，一批以550˚C/24h、爐冷的方式進行均質化處理，另外一批不均質化處理。這兩批分別進行450˚C熱鍛、鍛壓量70%再作T6熱處理（固溶520˚C/2h，時效167 ˚C/24h）。探討不同微量元素添加及T6處理後的機械性質以及顯微組織。
實驗結果顯示，6061、6061+Cr及6061+Mn鋁合金經由T6處理後硬度皆有明顯的提升，而強度方面在添加Cr 0.3%及Mn 0.7%時有最大值。而且已均質化之合金其強度皆小於未作均質化之合金。

關鍵字

Cr ； 6061 ； Mn ； T6熱處理。 ； 均質化

並列摘要

The effects of trace elements chromium (Cr) and manganese (Mn) addition on aluminum-magnesium-silicon alloys were investigated. The alloys of interest are AA6061. Alloys design of the casted 6061, 6061+Cr and 6061+Mn aluminum alloys by melting furnace. The alloys were homogenizated at 550˚C for 24hrs and furnace cooling. After hot forging process, the alloys were solid solution treated at 520˚C for 2 hrs and then aged at 167˚C for 24hrs; Mechanical properties test results are reports. Moreover, the morphologies of casted and T6-heat treated after hot forging were observed by optics microscope (OM).

Results indicated that after T6 treatment, the hardness of 6061, 6061+Cr and 6061+Mn aluminum alloys increase obviously. 6061-Cr0.3% has a maximum strength among 6061-Cr x wt% (x=0.1, 0.3, 0.4, 0.5). 6061-Mn 0.7% has a maximum strength among 6061-Mn y wt% (y=0.1, 0.2, 0.5, 0.7, 0.9, 1.1). The strength of homogenized alloys are lower than non-homogenized alloys.

並列關鍵字

homogenization ； Cr ； 6061 ； T6 heat treatment. ； Mn

參考文獻

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