摘要
为了制备含有C40相、较高Al元素掺杂量以及高流动性的优质 Mo(Si,Al)_2喷涂粉末,使用自蔓延燃烧合成法制备不同Al掺杂量的(x=0.1,0.2,0.3,0.4,0.5)Mo(Si1-x,Alx)_2粉末,通过X射线衍射分析确定Mo(Si_(0.6),Al_(0.4))_2为最优产物,采用一系列不同工艺参数的感应等离子球化工艺改善粉末的流动性。通过在鞘气中加入氢气并且降低送粉率,制备具有优异流动性能(26.2 s/50 g)的喷涂粉末 Mo(Si,Al)_2。由于Al的损失以及氧化,导致球化后的粉末出现了成分偏析,且同一颗粒中出现各向异性的成分偏析,该现象是由于颗粒穿过等离子射流时的不均匀受热以及冷却造成。
In order to prepare high quality Mo（Si,Al）2 feedstock characterized with C40 phase, higher Al doping amount andexcellent flowability, Mo（Si1-x,Alx）2 with different Al contents （x=0, 0.1, 0.2, 0.3, 0.4, 0.5） were synthesized by self-propagatinghigh-temperature synthesis first and Mo（Si0.6,Al0.4）2 was confirmed as the suitable material through X-ray diffraction analysis. Aseries of tests with different parameters of induction plasma spheroidization were applied to improving the flowability of feedstock.Mo（Si,Al）2 feedstock with excellent flowability （26.2 s/50 g） was prepared through adding hydrogen into sheath gas and decreasingthe powder feeding rate. The composition segregation occurred in the spheroidized powder after Al consumption and oxidation. Theinhomogeneous structure of the same particle was caused by the asymmetric heating and cooling when particle passed through theplasma jet.
基金
Project (20101101120030) supported by International Graduate Exchange Program of Beijing Institute of Technology
supported by the Research Fund for the doctoral Program of Higher Education of China
关键词
Mo(Si
Al)2
C40相
自蔓延高温合成
感应等离子球化
成分偏析
Mo（Si, Al）2
C40 phase
self-propagating high-temperature synthesis
induction plasma spheroidization
compositionsegregation
