摘要
用超重力下燃烧合成(combustion synthesis under high gravity)法制备了(Ti,W)C基复合陶瓷。用X射线衍射仪、场发射扫描电镜及能谱仪研究了陶瓷产品的物相组成与微观形貌。对陶瓷的形成机理进行了分析,同时对陶瓷的性能进行了测试。结果表明:(Ti,W)C陶瓷基体主要由TiC与(Ti0.55W0.45)C0.51组成;其形成机理主要分为两个阶段,首先在超重力下燃烧反应快速进行,生成液态氧化物位于上部、Ti-W-Fe-C-B合金液位于下部的分层熔体结构,最后由于C原子相对于B原子具有更高的浓度与更快的扩散速率,TiC在合金液相冷却过程中优先成核、析出,随即,(Ti0.55W0.45)C0.51依附于TiC而析出。力学性能测试表明,(Ti,W)C基复合陶瓷相对密度、Vickers硬度、弯曲强度及断裂韧性分别为99.3%,25.6GPa,1060MPa与8.5MPa·m1/2。
（Ti,W）C matrix composite ceramics were fabricated by the combustion synthesis under high gravity. The phase composition and morphologies of the as-prepared ceramics were characterized by X-ray diffractometer,field emission scanning electron microscope and energy dispersive X-ray spectrometer. The formation mechanism was evaluated and properties were also analyzed. The results show the ceramic matrix is mainly composed of TiC and （Ti0.55W0.45）C0.51. The formation mechanism mainly involves two stages：first,the combustion reaction advances rapidly under high gravity,and the layered melt consisting of Ti-W-Fe-C-B liquid at the bottom and oxide liquid at the top is formed due to rapid liquid-liquid separation under high gravity; and then,TiC solids as the primary phase precipitates from Ti-W-Fe-C-B liquid due to the higher concentration and faster diffusion of C than those of B in the alloy liquid,whereas （Ti0.55W0.45）C0.51 nucleates on the surface of TiC solids,so （Ti,W）C carbide grows directly from the melt. The Vickers hardness,flexural strength and fracture toughness of the （Ti,W）C matrix composite ceramic are 25.6 GPa,1 060 MPa and 8.5 MPa？m1/2,respectively.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2010年第8期1463-1467,共5页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(50672131)资助项目
关键词
碳化钨钛
复合陶瓷
燃烧合成
超重力
熔体凝固
titanium tungsten carbides
composite ceramics
combustion synthesis
high gravity
melt solidification
