增强相的反应合成
(清华大学 机械工程系, 北京 100084)
摘 要: 利用Cu与Fe具有液相分离特性， 以及母材与堆焊材料的冶金反应， 采用聚焦光束堆焊制备了Fe3Si弥散分布的铜基合金复合堆焊层。采用X射线衍射、 SEM、 EDS及显微硬度分析等方法研究了堆焊层的物相组成和微观组织特征。 实验结果表明，聚焦光束堆焊过程中， 由母材熔化而进入熔池的Fe元素与熔池中的Cu合金呈液相分离状态， 进入溶池的Fe由于密度小而上浮， 上浮过程中与熔池中的Si反应生成Fe3Si。 Fe3Si在堆焊层中弥散分布于α-Cu基体中， 分布密度由堆焊层表面向下呈减小趋势。
关键字: Fe3Si增强相；反应合成； 液相分离现象； 铜基自熔合金； 光束堆焊
（Department of Mechanical Engineering，
Tsinghua University， Beijing 100084， China）
Abstract: Based on liquid separation characteristic between Cu and Fe, and the reaction within base metal and the surfacing material, the copper matrix composite coating dispersed with Fe3Si reinforcement was obtained by light beam surfacing. With X-ray diffraction, SEM, EDS and microhardness test, the microstructure and the phase of the surfacing layer were studied. The results show that liquid Fe coming from base metal separates from copper alloy in the molten pool, then floats up because of its lower density, and reacts with Si in the molten pool to form Fe3Si. Fe3Si reinforcement disperses in α-Cu matrix, and its content decreases from top to bottom in the surfacing layer.
Key words: Fe3Si reinforcement; reaction synthesis; liquid separation characteristics; Cu-based self-fluxing alloy; light beam surfacing
