纯钨/310不锈钢异种材料激光熔化沉积探究

Exploration on pure tungsten/310 stainless steel dissimilar materials laser melting deposition

摘要:

采用激光熔化沉积的方法，在310S奥氏体不锈钢钢表面进行纯钨材料的增材制造．结合金相显微镜 (OM)、扫描电子显微镜 (SEM)、能谱分析 (EDS) 、X 射线衍射 (XRD) 及显微硬度仪等材料表征手段，对试样的微观组织结构、元素分布、物相组成及显微硬度进行了对比分析．结果表明：沉积层内部存在未完全熔化的钨颗粒，同时也存在完全熔化后重新凝固的富钨组织，其为金属间化合物Fe₇W₆，并且该化合物主要以枝晶形式存在；未完全熔化的钨颗粒与铁基基质呈良好的冶金结合，结合界面生成了Fe₇W₆/W的核壳结构．

Abstract:

In this study， pure tungsten is deposited on 310S austenitic stainless steel substrate by directed energy deposition （DED）. The microstructure characteristics， elements distribution， phases， and microhardness were analyzed via a series of advanced material characterization methods including optical microscope （OM）， scanning electron microscope （SEM）， energy-dispersive X-ray spectroscopy （EDS）， X-ray diffraction （XRD） and microhardness tester. The results show that there are incompletely melted tungsten particles exist in the deposited layer， and also a tungsten-rich structure that resolidifies after being completely melted， which is an intermetallic compound Fe₇W₆ and mainly exists in the form of dendrites. The incompletely melted tungsten particles metallurgically bond with the iron matrix， and a core-shell structure of Fe₇W₆/W is formed at the bonding interface.