摘要
A comparative study was conducted by using solution combustion synthesis with three different doping routes(liquid-liquid(WL10), liquid-solid(WLNO) and solid-solid(WLO)) to produce nanoscale powders and further fabricate the ultrafine-grained W-1.0 wt.%La2O3 alloys by pressureless sintering. Compared with pure tungsten, W-1.0 wt.%La2O3 alloys exhibit ultrafine grains and excellent mechanical properties. After sintering, the average grain size of the WLO sample is larger than that of WL10 and WLNO samples;the microhardness values of WL10 and WLNO samples are similar but larger than the value of WLO sample. The optimized La2O3 particles are obtained in the WL10 sample after sintering at 1500 ℃ with the minimum mean size by comparing with WLNO and WLO samples, which are uniformly distributed either at grain boundaries or in the grain interior with the sizes of(57±29.7) and(27±13.1) nm, respectively. This study exhibits ultrafine microstructure and outperforming mechanical properties of the W-1.0 wt.%La2O3 alloy via the liquid-liquid doping route, as compared with conventionally-manufactured tungsten materials.
对采用溶液燃烧合成法并结合不同掺杂方法(液-液(WL10)、液-固(WLNO)和固-固(WLO))制备的纳米尺度粉末及采用常压烧结法制备的超细晶W-1.0wt.%La2O3合金进行对比研究。与纯钨相比,W-1.0wt.%La2O3合金具有超细晶粒和优异的力学性能。烧结后,WLO样品的平均晶粒尺寸大于WL10和WLNO样品的平均晶粒尺寸;WL10和WLNO的显微硬度相差不大,但大于WLO的显微硬度。相对于其他样品,在1500℃烧结后的WL10样品中La2O3颗粒呈现最佳分布状态,均匀分布在晶界或晶粒内部,且平均尺寸最小,晶界和晶粒内部的La2O3颗粒平均尺寸分别为(57±29.7)和(27±13.1)nm。与传统方法制备的钨材料相比,采用液-液掺杂方法制备的W-1.0wt.%La2O3钨合金呈超细的显微组织和优异的性能。
基金
Projects(2017YFB0306000,2017YFB0305600)supported by the National Key Research and Development Program of China
Projects(51774035,51604025,51574031,51574030,51574029,51604240)supported by the National Natural Science Foundation of China
Project(2019JZZY010327)supported by the Shandong Key Research and Development Plan Project,China
Projects(2174079,2162027)supported by the Natural Science Foundation Program of Beijing,China
Projects(FRF-IDRY-19-025,FRF-TP-17-034A2,FRF-TP-19-015A3,FRF-IDRY-19-003C2)supported by the Fundamental Research Funds for the Central Universities of China。
