(南京航空航天大學(xué) 機電學(xué)院，南京 210016)
摘 要: 利用冷等靜壓法將摻有粘結(jié)劑的SiC納米顆粒壓制成塊體并經(jīng)大功率CO2激光器照射，在激光照射區(qū)域獲得SiC晶須，利用掃描電鏡對晶須進行觀察，分析照射層不同區(qū)域和不同氣氛環(huán)境下晶須形態(tài)的變化。結(jié)果表明：不同氣氛環(huán)境下晶須形態(tài)有顯著區(qū)別，分別表現(xiàn)為放射狀團簇特征、螺旋狀團簇特征和密排短棒狀團簇特征；同一照射層內(nèi)，不同區(qū)域晶須形態(tài)也不一致，沿光束入射方向，可見以較大晶粒為核心的團簇狀小長徑比晶須和數(shù)量豐富、形態(tài)良好的大長徑比晶須；不同的氣氛組分和光強梯度分布是造成晶須形態(tài)不同的主要原因。
關(guān)鍵字: 激光照射；原位生長；SiC晶須；形態(tài)
（College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics,
Nanjing 210016, China）
Abstract:The in-situ growth of SiC whiskers by laser irradiation directly on nano-particles mixed with binder and compressed by the cold isostatic pressing method was performed. The morphologies of SiC whiskers were observed by means of the scanning electron microscopy. The results show that the whiskers exhibit, respectively, as the feature of actinomorphic cluster, helical cluster and short-rod cluster, which grow in the specimen with the binder. In the different irradiation regions within discretionary specimen, the whiskers morphologies are not alike. Along the direction of incidence of laser beam, the whiskers with small long-diameter ratio grow around the large crystal grain in the middle region of irradiation layer, the shape of them is the short-rod. At the bottom, the abundant and fine whiskers with the feature of large long-diameter ratio are observed. The gasification products of different binders and the grads distributing of laser intensity are the master factors to cause different whisker morphologies.
Key words: laser irradiation; in-situ growth; SiC whiskers; morphology
