Si、Na掺杂W基高比重合金液相烧结过程中的界面反应

INTERFACE REACTIONS IN LIQUID-SINTERING TUNGSTEN HEAVY ALLOY WITH Si, Na IMPURITIES

对不同Si、Na掺杂量的W－（Ni，Fe）高比重合金进行了扫描电镜、透射电镜、X射线光电子能谱（XPS）及俄歇能谱（AES）分析，探讨了Si、Na掺杂在W－（Ni，Fe）及W－W界面所发生的反应，以及此类反应对合金显微结构所产生的影响。研究发现，Si、Na掺杂使合金出现孔隙并在W－（Ni，Fe）界面出现层状SiO2夹杂相，SiO2与液相Ni、Fe的低润湿性以及Na的挥发性是造成这种影响的根本原因。

SEM,TEM,XPS,and AES are used to analyze heavy alloys with different contents of trace impurities of Si and Na. The reactions caused by Si and Na at the interface of W-(Ni,Fe) and W-W and their effects on the microstructure of heavy alloy are also studied. It is found that the trace impurities of Si and Na result in the formation of pore and layer impurity phase of SiO2 at the interface of W-(Ni, Fe). The low Wettability between SiO2 and Ni,Fe and the volatility of Na during liquid phase sintering are the main reasons for such effect.