Positron Annihilation Study on TiC Powders

Titanium carbonitride (Ti(C, N)) based cermets are characterized by their high creep andwear resistance. These properties made themsuitable for cutting tool applications 11].Ti(C,N) cermets possess a very fine-grainedand stable microstyllctdre. This is attribllted tothe formation of a rim or shell around theTi(C, N) core, thereby enhancing the wetting ofthe carbonitrides to the metal binder and ililiibiting the coalescence and growth of the carbonitride grains dUring sintering. The core/ri…  

氧化镧的加入对PREP制备钨粉末性能的影响

采用等离子旋转电极雾化技术（plasma rotating electrode processing，PREP）制备出纯W和W-La合金球形粉末，对比分析了两种类型粉末的化学成分、形貌、物理性能、缺陷和粒度分布。结果表明：PREP法制备的球形纯W粉末表面光滑、球形度高，小于106 μm粉末的收得率为70%。在棒料中加入La2O3后，大部分La2O3在PREP过程中挥发，残余的La2O3优先附着于液滴表面，降低了的液态金属钨的表面张力，将小于106μm粉末的收得率提升至90%；但是，表面张力的降低同时也导致W-La合金粉末表面出现少量缺陷。La2O3提高粉末收率的现象为研究提高PREP技术粉末收率提供了新思路。