銅-25錳-25鋁和銅-25錳-35鋁合金淬火顯微結構

Abstract

我們利用穿透式電子顯微鏡(TEM)以及X光能量分佈儀(EDS)來觀察銅-25 錳 -25鋁(合金 A)和銅-25錳-35鋁(合金 B)的淬火顯微結構結果發現如下 ：當合金 A 經850℃作固溶處理1小時後，淬火於冰食鹽水中，發現有細 小的析出物在基地內形成，分析包含析出物及其周圍基地的選擇區域繞射 圖形。結果發現Cu-25Mn-25Al(Cu2MnAl，合金 A)的淬火顯微結構為(L21 ＋ω)相的混合，此結果與其它學者所觀察到的單一L21相不同。當合金 B 經850℃作固溶處理1小時後，淬火於冰食鹽水中，Cu-25Mn- 35Al(合 金 B)的淬火顯微結構為(L21＋B2＋ω)相的混合，此結果與其它研究學者 在Cu3-xMnxAl合金系統中所觀察到的顯微結果截然不同。 The as-quenched microstructures of Cu-25Mn-25Al ( Alloy A ) and Cu-25Mn-35Al ( Alloy B ) alloys have been investigated by using transmission electron microscopy ( TEM ) and energy-dispersive X-ray spectrometer. ( EDS) The experimental results are summarized as follow: When the alloy A was solution heat- treated at 850℃ for 1 hour and then quenched into iced brine rapidly. There are some fine precipitates presented within the matrix in the as-quenched specimen. From the analyses of the selected-area diffraction patterns ( SADPs ) taken from an area which covers fine precipitates and their surrounding matrix, it is concluded that the as-quenched microstructure of the Cu-25 Mn-25Al ( Cu2MnAl, Alloy A ) alloy is a mixture of ( L21 + w ) phases, rather than a single L21 phase reported by other workers in the as-quenched Cu2MnAl alloy. When the alloy B was solution heat-treated at 850℃ for 1 hour and then rapidly quenched into iced brine. The microstructure of the Cu-25Mn-35 Al (Alloy B ) alloy is a mixture of ( L21 + B2 + w ) phases, which is quite different from that reported by other workers in the Cu3-xMnxAl alloy system.