CAJ | 학술논문

采用溶胶喷雾干燥-煅烧还原方法制备超细/纳米W-La2O3复合粉末，将粉末压制成形后在1950℃烧结，制备 La2O3弥散强化钨合金，检测合金的密度与强度，并采用 SEM 对超细粉末形貌、合金的组织结构、断口形貌进行分析，结果表明：随La2O3加入量增加，粉末颗粒显著细化，W-0.7%La2O3复合粉末的粒径仅为0.1μm；制备的W-La2O3超细/纳米复合粉末具有很高的烧结活性，烧结后，合金最高相对密度达到99.1%；La2O3均匀弥散分布于钨晶界，抑制钨合金的晶粒长大，提高材料的强度，W-0.7%La2O3合金中钨平均晶粒尺寸仅为8.7μm，抗弯强度达到548 MPa；合金的断裂形式表现为穿晶-沿晶共有的复合断裂形式。
채용용효분무간조-단소환원방법제비초세/납미W-La2O3복합분말，장분말압제성형후재1950℃소결，제비 La2O3미산강화오합금，검측합금적밀도여강도，병채용 SEM 대초세분말형모、합금적조직결구、단구형모진행분석，결과표명：수La2O3가입량증가，분말과립현저세화，W-0.7%La2O3복합분말적립경부위0.1μm；제비적W-La2O3초세/납미복합분말구유흔고적소결활성，소결후，합금최고상대밀도체도99.1%；La2O3균균미산분포우오정계，억제오합금적정립장대，제고재료적강도，W-0.7%La2O3합금중오평균정립척촌부위8.7μm，항만강도체도548 MPa；합금적단렬형식표현위천정-연정공유적복합단렬형식。
Ultrafine/nano composite powders of W-La2O3 were prepared by Sol-spray drying-calcination-hydrogen reduction process, and sintered at 1 950 ℃ to form La2O3 dispersion strengthened tungsten materials and obtain high density after molding under the press of 275 MPa. The density and mechanical properties of the alloy were studied. Morphologies of superfine powder, microstructure and fracture morphology of the sintered materials were investigated by SEM. The results show, with increasing the amount of La2O3, particles size of the powder decreases. The BET particle size of W-0.7%La2O3 composite powder is 0.1μm. The highest relatively density can reach 99.1%after sintering due to high sintering activity of W-La2O3 ultrafine/nano composite powders. La2O3 uniformly disperses on the tungsten grain boundary and inside, which can restrain the grain growth process. As a result, the average grain size of W-0.7%La2O3 is 8.7μm. The property of La2O3 dispersion strengthened tungsten materials is greatly improved , the flexural strength of W-0.7%La2O3 is 548 MPa. The morphologies of fracture surface of W-La2O3 alloy show a mixed mode of transgranular and intergranular fracture.