MoSi_2-SiC复合材料的制备及其抗氧化性研究  

Preparation and oxidation resistance of MoSi_2-SiC materials

作　　者：雷乃旭 王文武[1] 万龙刚[1] 吴吉光[1] Lei Naixu;Wang Wenwu;Wan Longgang;Wu Jiguang

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039

出　　处：《耐火材料》2018年第5期365-367,共3页Refractories

摘　　要：先以SiC(粒度分别为≤2.5、≤0.062 mm)为主要原料,水溶性树脂为结合剂,经混练、成型、烘干后得到SiC坯体,再用MoSi_2微粉(d_(50)=3μm)掩埋SiC坯体,在真空条件下2 000℃保温3 h进行熔渗烧结,以直接熔渗法制备出MoSi_2-SiC复合材料,并与R-SiC和Si_3N_4-SiC材料一起进行在空气中于1 600℃的静态抗氧化试验,以对比研究其抗氧化性能。结果表明:经1 600℃氧化75 h后,Mo Si_2-SiC复合材料的抗氧化性优于R-Si C、Si_3N_4-SiC材料的;Mo Si_2在烧结过程中部分发生分解生成了Mo_5Si_3,Mo Si_2、Mo_5Si_3填充于Si C的内部并实现烧结致密化,使Mo Si_2-SiC复合材料的显气孔率显著降低至5.7%;Mo Si_2-SiC复合材料中Mo Si_2、Mo_5Si_3含量(w)分别为10%~15%、3%~5%,1 000℃下的热导率为46.5 W·m^(-1)·K^(-1),显著高于R-SiC和Si_3N_4-SiC材料的。SiC blocks were prepared using SiC （particle size ≤ 2.5 mm, ≤ 0.062 mm） as the main raw material and water-soluble resin as the binder,mixing, molding ,and drying. Then the blocks were buried with MoSi2 micropowder （d50 =3 μm） and sintered at 2 000 ℃ for 3 h in vacuum to obtain MoSi2-SiC composites by direct infiltration method. The static oxidation resistances of the developed composite, R-SiC and Si3N4-SiC materials in air at 1 600 ℃ were compared. The results show that after oxidation at 1 600 ℃ for 75 h,the oxidation resistance of MoSi2-SiC composite is better than that of R-SiC or Si3N4-SiC materials. During the sintering process,MoSi2 partially decomposes into MosSi3. The MoSi2 and Mo5Si3 fill in SiC and densify the structure by sintering. The apparent porosity of MoSi2-SiC composites significantly reduces to 5.7%. The content of MoSi2 and Mo5Si3 in MoSi2-SiC composites is 10% -15% and 3% -5%, respectively. The thermal conductivity of MoSi2-SiC composites is 46.5 W · m -1· K-1 , significantly higher than that of R-SiC and Si3N4-SiC materials.

关 键 词：MOSI2-SIC复合材料 MOSI2 重结晶SiC材料 直接熔渗法 抗氧化性 

分 类 号：TQ175[化学工程—硅酸盐工业]