功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2015年
5期
5128-5131,5135
,共5页
郭圣达%羊建高%陈颢%朱二涛%张雪辉
郭聖達%羊建高%陳顥%硃二濤%張雪輝
곽골체%양건고%진호%주이도%장설휘
直接碳化原位合成%WC-Co 复合粉%碳化%吉布斯自由能%促进作用
直接碳化原位閤成%WC-Co 複閤粉%碳化%吉佈斯自由能%促進作用
직접탄화원위합성%WC-Co 복합분%탄화%길포사자유능%촉진작용
direct carbonization in situ synthesis%WC-Co composite powder%carbonation%gibbs free energy%pro-mote
以偏钨酸铵(AMT)、可溶性钴盐、有机碳源为原材料,采用喷雾转化、直接碳化原位合成法,成功制备出 WC-Co 复合粉末。利用 XRD、SEM等分析方法对粉末样品物相组成、微观形貌、粒度分布进行了研究。研究表明,由于 Co 对 W 碳化的促进作用,在900℃时,W就被完全碳化为 WC,远低于 W 正常被碳化完全的温度;W的碳化过程主要依靠钨粉颗粒表面与含碳气氛热解后沉积在钨颗粒表面上的碳元素的反应以及碳向钨粉颗粒内部的扩散来实现,属固-固反应;由于生成 W2 C的自由能比 WC 的更低,W很快先被碳化为 W2 C,然后再进一步碳化为 WC;W/Co/C碳化反应体系沿 WCo3,Co6 W6 C,W2 C-Co,WC-Co 步骤进行反应;随着温度的升高,反应体系可不经过前两步,而直接生成 W2 C-Co,再进一步碳化为 WC-Co 复合粉。
以偏鎢痠銨(AMT)、可溶性鈷鹽、有機碳源為原材料,採用噴霧轉化、直接碳化原位閤成法,成功製備齣 WC-Co 複閤粉末。利用 XRD、SEM等分析方法對粉末樣品物相組成、微觀形貌、粒度分佈進行瞭研究。研究錶明,由于 Co 對 W 碳化的促進作用,在900℃時,W就被完全碳化為 WC,遠低于 W 正常被碳化完全的溫度;W的碳化過程主要依靠鎢粉顆粒錶麵與含碳氣氛熱解後沉積在鎢顆粒錶麵上的碳元素的反應以及碳嚮鎢粉顆粒內部的擴散來實現,屬固-固反應;由于生成 W2 C的自由能比 WC 的更低,W很快先被碳化為 W2 C,然後再進一步碳化為 WC;W/Co/C碳化反應體繫沿 WCo3,Co6 W6 C,W2 C-Co,WC-Co 步驟進行反應;隨著溫度的升高,反應體繫可不經過前兩步,而直接生成 W2 C-Co,再進一步碳化為 WC-Co 複閤粉。
이편오산안(AMT)、가용성고염、유궤탄원위원재료,채용분무전화、직접탄화원위합성법,성공제비출 WC-Co 복합분말。이용 XRD、SEM등분석방법대분말양품물상조성、미관형모、립도분포진행료연구。연구표명,유우 Co 대 W 탄화적촉진작용,재900℃시,W취피완전탄화위 WC,원저우 W 정상피탄화완전적온도;W적탄화과정주요의고오분과립표면여함탄기분열해후침적재오과립표면상적탄원소적반응이급탄향오분과립내부적확산래실현,속고-고반응;유우생성 W2 C적자유능비 WC 적경저,W흔쾌선피탄화위 W2 C,연후재진일보탄화위 WC;W/Co/C탄화반응체계연 WCo3,Co6 W6 C,W2 C-Co,WC-Co 보취진행반응;수착온도적승고,반응체계가불경과전량보,이직접생성 W2 C-Co,재진일보탄화위 WC-Co 복합분。
Using ammonium metatungstate (AMT),soluble cobalt salt,and organic carbon source as the raw materials,the WC-Co composite powder was fabricated by spray conversion method and direct carbonized in-si-tu synthesize method.The phase compositions,powder morphology of WC-Co composite powder were charac-terized by XRD,SEM.Results show that W was carbonized completely at 900 ℃ because of the promoting effect of Co phase,the carbonize temperature in this experiment of W was lower than the normal carbonize tem-perature far;The carbonization process of W depends on the reaction of the surface of tungsten powder particles and carbon which resolved from carbon atmosphere,and the diffusion of carbon to the inside of W particles, was a solid-solid reaction,W was carbonized into W2 C firstly,and then carbonized into WC further because of the Gibbs free energy of W2 C is lower than WC;The W/Co/C system reacted along the specific steps of WCo3 , Co6 W6 C,W2 C-Co and WC-Co;With the increasing of carbonize temperature,the reaction system can skip the first two steps,and generated W2 C-Co directly,then carbonized into WC-Co composite powder further.