Use of Post-heat Treatment to Obtain a 2H Solid Solution in Spark Plasma Sintering-Processed AlN–SiC Mixtures
作者:Ryota Kobayashi、Junichi Tatami、Toru Wakihara、Katsutoshi Komeya、Takeshi Meguro、Takashi Goto、Rong Tu
DOI:10.1111/j.1551-2916.2008.02307.x
日期:2008.5
Dense aluminum nitride–silicon carbide (AlN–SiC) solid solutions with a 2H structure were fabricated by the post‐heat treatment of dense AlN–SiC composites fabricated by spark plasma sintering (SPS). The changes in the relative density, microstructure, and phases present were investigated for the compositions of 25 mol% AlN–75 mol% SiC (AlN 25), 50 mol% AlN–50 mol% SiC (AlN 50), and 75 mol% AlN–25 mol% SiC (AlN 75). The AlN–SiC composites fabricated by the SPS were dense ceramics with fine microstructures and composed of 2H and 6H AlN–SiC solid solutions. The AlN 50 samples heat treated at 2200°C and the AlN 75 samples heat treated at 2100°C were also dense ceramics and composed of only the 2H AlN–SiC solid solution. In contrast, the AlN 25 samples heat treated at 2200°C were porous ceramics and composed of several AlN–SiC solid solutions (2H, 4H, 6H, and 15R), and the AlN 75 samples heat treated at 2200°C were decomposed into an Al melt. Dense AlN–SiC solid solutions composed of only the 2H phase can be obtained by controlling the heat‐treatment temperatures, except for the AlN 25 sample.
通过火花浆料烧结(SPS)制备致密的铝氮化物-碳化硅(AlN-SiC)复合材料,并随后通过热处理得到了具有2H结构的致密AlN-SiC固溶体。研究了三种组分(25 mol% AlN-75 mol% SiC(AlN 25)、50 mol% AlN-50 mol% SiC(AlN 50)和75 mol% AlN-25 mol% SiC(AlN 75)的相对密度、微观结构和存在相的变化。通过SPS制备的AlN-SiC复合材料为致密陶瓷,具有精细的微观结构,由2H和6H AlN-SiC固溶体组成。在2200°C下热处理的AlN 50样品和在2100°C下热处理的AlN 75样品均为致密陶瓷,仅由2H AlN-SiC固溶体组成。相比之下,在2200°C下热处理的AlN 25样品为多孔陶瓷,由多种AlN-SiC固溶体(2H、4H、6H和15R)组成,而在2200°C下热处理的AlN 75样品分解为铝熔体。通过控制热处理温度,可以获得仅由2H相组成的致密AlN-SiC固溶体,除了AlN 25样品。