(西安理工大學 陜西省電工材料與熔滲技術(shù)重點實驗室，西安 710048)
摘 要: 為了改善CuNiMnFe多元合金組織內(nèi)樹枝晶尺寸及成分偏析，提高合金力學性能，在合金熔煉過程中添加微量硼進行變質(zhì)處理，采用掃描電子顯微鏡、透射電子顯微鏡及能譜分析儀對CuNiMnFe合金的組織形貌及物相進行表征，并采用布氏硬度計和萬能材料試驗機分別對合金硬度和抗拉強度進行測試。結(jié)果表明：硼元素對CuNiMnFe合金組織變質(zhì)效果明顯，在0~0.15%B(質(zhì)量分數(shù))范圍內(nèi)，隨著硼添加量的增加，CuNiMnFe合金組織中樹枝晶得到細化，二次晶臂間距減小，共晶β相減少，枝晶內(nèi)析出顆粒狀次生β相與釘狀γ相增多。當硼的添加量為0.10%時，合金組織內(nèi)樹枝晶二次晶臂間距最小，板條狀共晶β相基本消失，枝晶內(nèi)顆粒次生β相與釘狀γ相明顯。CuNiMnFe合金鑄態(tài)硬度及熱處理后的硬度也隨著硼的添加量的增加呈先增大后減小的趨勢。當硼的添加量為0.10%時，合金鑄態(tài)硬度達到峰值，熱處理后硬度仍保持最大值HB380，同時，合金抗拉強度達到1 130 MPa。
關(guān)鍵字: CuNiMnFe合金；硼；樹枝晶；變質(zhì)處理；析出相
（Shaanxi Province Key Laboratory for Electrical Materials and Infiltration Technology,
Xi’an University of Technology, Xi’an 710048, China）
Abstract:In order to refine the dendrite and eliminate the segregation of CuNiMnFe alloy, the molten CuNiMnFe alloy was modified by trace boron addition. The effect of the modification treatment on microstructures and properties of the CuNiMnFe alloy was studied, the microstructure and phase were characterized by the scanning electron microscope, transmission electron microscope and energy dispersive spectrum, and the hardness and tensile strength of alloys were measured on Brinell hardness tester and universal material testing machine, respectively. The results show that B addition has a significant effect on the microstructures of CuNiMnFe alloy. In the range of 0-0.15%B (mass fraction), the increased boron addition can refine the dendrite microstructure, reduce the secondary dendrite arm spacing (SDAS) and the amount of eutectic β phase, while the precipitation of the secondary β and nail-head γ phase inside the dendrites increase. At 0.10%B, SDAS is the least, the lamellar eutectic β phase almost disappears, and the obvious secondary β phase and nail-head γ phase inside the dendrite. With the boron adding, the as-cast hardness and aged hardness of the CuNiMnFe alloy increase at first, and then decrease. The as-cast CuNiMnFe alloy with 0.1%B addition has the peak hardness, and the aged peak hardness can remain the maximum hardness value of HB380. The tensile strength of aged CuNiMnFe alloy can reach up 1 130 MPa.
Key words: CuNiMnFe alloy; boron; dendrite; modification; precipitated phase
