Preparation of dense spherical AlN fillers by aqueous granulation and post-sintering process

详细信息    查看全文

• 作者：Qi Wang^a ; ^{wangqi15@ustb.edu.cn} ; Yiyao Ge^b ; Siyuan Sun^b ; Jianlei Kuang^a ; José ; M.F. Ferreira^c ; Wenbin Cao^a
• 关键词：Dispersing ability ; Aqueous granulation ; Post-sintering process ; Spherical AlN fillers
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：43
• 期：2
• 页码：2027-2032
• 全文大小：1985 K
• 卷排序：43

文摘

Herein, an innovative two-step method was proposed to prepare dense spherical aluminum nitride (AlN) fillers for the application of insulating encapsulants, involving spray granulation from AlN-based suspensions and subsequent sintering process to achieve full density. According to investigations on the dispersing ability of powders, the AlN-based aqueous suspensions with various solid loading were firstly prepared for spray granulation. It was indicated that a low-viscosity and high-concentration suspension could enhance the sphericity and uniformity of green granules and simultaneously facilitate the high green density. The spherical AlN green granules were further sintered with boron nitride (BN) powders, which played a role as the interval material to retain the spherical morphology and hinder the agglomerations of AlN granules. The distinct impacts of BN powders, sintering temperatures and additive species on the overall properties of resultant AlN fillers were further studied and rationally uncovered. Based on these results, spherical AlN granules with superior dispersion, low porosity and an average particle size of more than 40 µm were successfully fabricated via the newly-developed two-step method, showing promising potentiality for the application as thermal-conductive fillers.