紫钨喷雾干燥-直接碳化法制备纳米WC-Co复合粉
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摘要
以WC-6%Co为基本成分,计算原料紫钨、醋酸钴、有机碳及超纯炭黑配料量,称量后加入装有适量纯水的可倾斜式滚动球磨机,湿磨混匀12 h,形成复合盐料浆,然后充分搅拌,进行喷雾干燥后制备的前驱体粉末粒度在10~100μm,平均粒度为50μm。将喷雾干燥好的粉末装舟(200 g),推入高温钼丝炉中,通入氢气,还原碳化温度950℃,时间30min制备的纳米WC-Co复合粉,粉末粒度分布窄,颗粒粒度在5~45μm,平均粒度为23.38μm。SEM、BET结果表明WC晶粒度在300 nm左右,由扫描电镜(SEM)、X光微区分析(EDS)及元素面分布图得到,W、Co、C分布均匀、Co相均匀包覆在WC晶粒周围,不存在成分偏析。XRD的半高宽窄,晶粒细小;物相纯净,无η相。
Using WC-6 % Co as raw materials, the ingredients of violet tungsten oxide, cobalt acetate, organic carbon and ultrapure carbon are calculated. Then these ingredients are mixed wet with pure water in the inclinable rolling mill for 12 h. The complex salt slurry formed is sufficiently stirred with spray drying at 230 ℃ inlet temperature and 125 ℃ outlet temperature with 60 mL/min feeding rate and 12 000 r/min spinner speed. Then precursor powder is prepared. Its size is about 10~100μm with the average particle size 50 μm. The spray dried powders are loaded in boat( 200 g), then pushed into the heated molybdenum wire furnace. Hydrogen gas is then charged, carburized & reduced at 950 ℃ for 30 min. In this way, nano WC-Co composite powder was prepared with a narrow particle size distribution( particle size 5~45 μm, an average particle size of 23.38 μm). SEM and BET data indicate the grain size of WC is about 300 nm. SEM, X ray microanalysis( EDS) and the element distribution images shows that W, Co, C distribute uniformly with uniform Co phase coating around WC grain without segregation.The half height width of XRD shows fine grain size, pure phase without η phase.
Using WC-6 % Co as raw materials, the ingredients of violet tungsten oxide, cobalt acetate, organic carbon and ultrapure carbon are calculated. Then these ingredients are mixed wet with pure water in the inclinable rolling mill for 12 h. The complex salt slurry formed is sufficiently stirred with spray drying at 230 ℃ inlet temperature and 125 ℃ outlet temperature with 60 mL/min feeding rate and 12 000 r/min spinner speed. Then precursor powder is prepared. Its size is about 10~100μm with the average particle size 50 μm. The spray dried powders are loaded in boat( 200 g), then pushed into the heated molybdenum wire furnace. Hydrogen gas is then charged, carburized & reduced at 950 ℃ for 30 min. In this way, nano WC-Co composite powder was prepared with a narrow particle size distribution( particle size 5~45 μm, an average particle size of 23.38 μm). SEM and BET data indicate the grain size of WC is about 300 nm. SEM, X ray microanalysis( EDS) and the element distribution images shows that W, Co, C distribute uniformly with uniform Co phase coating around WC grain without segregation.The half height width of XRD shows fine grain size, pure phase without η phase.
引文
[1]张武装,刘咏,黄伯云.纳米晶WC-Co硬质合金的研究现状[J].材料导报,2007,21(2):79-82.
[2]张凤林,崔晓龙,朱敏,等.高能球磨制备纳米WC-Co复合粉末及其SPS烧结[J].硬质合金,2007,24(2):80-83.
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[9]ZHOU Y T,MANTHIRAM A.Influence of processing parameters on the formation of WC-Co nanocomposite powder using a polymer as carbon source.Composite Part B,1996,27B(5):407-413.
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[11]魏崇斌,宋晓艳,赵世贤,等.超细WC-Co复合粉的原位反应合成及烧结致密化[J].粉末冶金材料科学与工程,2010,15(2):145-150.
[12]ZAWRAH M F.Synthesis and Characterization of WC-Co Nanocomposites by Novel Chemical Method[J].Ceramics International.2007,33(2):155-161.
[13]KEAR B K,MCANDLISH L E.Chemical processing and properties of nanostructured WC-Co matericals[J].Nanostuructured Matericals,1993,3(1/6):19-30.
[14]MCANDLISH L E,POLIZZOTTI R S.Control of compositionand microstructure in the Co-W-C system using chemical synthetic techniques[J].Solid State Ionics,1989,32-33(2):795-801.
[15]RUTGERS.Carbothermic reaction process for making nanophase WC-Co powders:US,5230729[P].1992-12-10.
[16]KEAR B K,MCANDLISH L E.Chemical processing and properties of nanostructured WC-Co materials[J].Nanostructured Materials,1993,3(1/6):19-30.
[17]汤昌仁,易茂中,谭兴龙.喷雾干燥-直接碳化法制备WC-Co复合粉末[J].粉末冶金技术,2010,28(4):279-283.
[18]羊建高,吕健,朱二涛,等.连续还原碳化法制备纳米WC-Co复合粉研究[J].有色金属材料与工程,2013,4(5):23-27.
[19]陈绍衣,钱崇梁.氧化钨氢还原过程中的物相转变[J].中南工业大学学报,1995,26(5):605-609
[20]BOCK A,ZEILER B.Production and characterization of ultrafine WC powders[J].International Journal of Refractory Metals and Hard Materials,2002,(20):23-30.
[21]吕健,羊建高,陈灏,等.喷雾干燥与低温还原碳化法制备纳米晶WC-Co复合粉[J].粉末冶金材料科学与工程,2013,18(6):835-839.
[2]张凤林,崔晓龙,朱敏,等.高能球磨制备纳米WC-Co复合粉末及其SPS烧结[J].硬质合金,2007,24(2):80-83.
[3]FAN Y S,LEI F,XIAN J D,etal.Preparation of nanosize WC-Co composite powders by plasma.Joumal of Materials Science Letters,1996,15(24):2184-2187.
[4]曹立宏,欧阳世翕.硬质合金WC-Co超细粉末的制备研究[J].硅酸盐学报,1996,24(5):604-608.
[5]徐志花,马淳安,甘永平.超细碳化钨及其复合粉末的制备[J].化学通报,2003,8:544-548.
[6]羊建高,谭敦强,陈颢.硬质合金[M].长沙:中南大学出版社,2012:138-140.
[7]张伟.WC-Co硬质合金纳米前驱粉的制备[D].北京:北京工业大学,2006:5-6.
[8]ZHOU Y T,MANTHIRAM A.A new route for the synthesis of tungsten carbide-cobalt nanocomposite.Journal of American Ceramic Society,1994,77(10):2777-2778.
[9]ZHOU Y T,MANTHIRAM A.Influence of processing parameters on the formation of WC-Co nanocomposite powder using a polymer as carbon source.Composite Part B,1996,27B(5):407-413.
[10]张久兴,宋晓艳,刘文彬.一种简单快速的超细WC-CO复合粉的制备方法:中国,CN1986124A[P].2007-06-26.
[11]魏崇斌,宋晓艳,赵世贤,等.超细WC-Co复合粉的原位反应合成及烧结致密化[J].粉末冶金材料科学与工程,2010,15(2):145-150.
[12]ZAWRAH M F.Synthesis and Characterization of WC-Co Nanocomposites by Novel Chemical Method[J].Ceramics International.2007,33(2):155-161.
[13]KEAR B K,MCANDLISH L E.Chemical processing and properties of nanostructured WC-Co matericals[J].Nanostuructured Matericals,1993,3(1/6):19-30.
[14]MCANDLISH L E,POLIZZOTTI R S.Control of compositionand microstructure in the Co-W-C system using chemical synthetic techniques[J].Solid State Ionics,1989,32-33(2):795-801.
[15]RUTGERS.Carbothermic reaction process for making nanophase WC-Co powders:US,5230729[P].1992-12-10.
[16]KEAR B K,MCANDLISH L E.Chemical processing and properties of nanostructured WC-Co materials[J].Nanostructured Materials,1993,3(1/6):19-30.
[17]汤昌仁,易茂中,谭兴龙.喷雾干燥-直接碳化法制备WC-Co复合粉末[J].粉末冶金技术,2010,28(4):279-283.
[18]羊建高,吕健,朱二涛,等.连续还原碳化法制备纳米WC-Co复合粉研究[J].有色金属材料与工程,2013,4(5):23-27.
[19]陈绍衣,钱崇梁.氧化钨氢还原过程中的物相转变[J].中南工业大学学报,1995,26(5):605-609
[20]BOCK A,ZEILER B.Production and characterization of ultrafine WC powders[J].International Journal of Refractory Metals and Hard Materials,2002,(20):23-30.
[21]吕健,羊建高,陈灏,等.喷雾干燥与低温还原碳化法制备纳米晶WC-Co复合粉[J].粉末冶金材料科学与工程,2013,18(6):835-839.