论文部分内容阅读
将SiC颗粒在空气中进行850~1100℃高温氧化增重试验。研究了氧化时间、氧化温度对SiC颗粒表面氧化行为和氧化层结构的影响。采用烧结温度500℃压力30MPa保压时间30min的热压烧结工艺,制备出体积分数为20%的SiC_P/Al复合材料。研究了SiC氧化过程对SiC_P/Al复合材料界面的影响。结果表明:SiC在850℃以上,随氧化时间延长或温度升高,氧化层从非晶态向晶态转变。1100℃氧化4 h后,SiO_2氧化层厚度为252nm。本文优化的正四面体模型计算厚度约190nm,传统球形模型计算厚度约110nm。氧化层中SiO_2主要为高温型方石英晶型;SiC颗粒氧化后与Al基体形成了SiC/SiO_2和Al_2O_3/Al复合界面组织。
SiC particles in the air at 850 ~ 1100 ℃ high temperature oxidation weight gain test. The effects of oxidation time and oxidation temperature on the oxidation behavior and oxide layer structure of SiC particles were investigated. The SiC_P / Al composites with volume fraction of 20% were prepared by hot-pressing sintering process with sintering temperature of 500 ℃ and pressure of 30MPa for 30min. The effect of SiC oxidation on the interface of SiC_P / Al composites was studied. The results show that when the temperature of SiC is above 850 ℃, the oxide layer changes from amorphous to crystalline with the increase of oxidation time or temperature. After oxidation at 1100 ℃ for 4 h, the thickness of SiO 2 oxide layer was 252 nm. The optimized tetrahedron model calculated the thickness of about 190nm, the traditional spherical model calculated thickness of about 110nm. The SiO 2 in the oxide layer is mainly of high-temperature cristobalite. The SiC / SiO 2 and Al 2 O 3 / Al interface structures are formed by the oxidation of SiC particles with the Al matrix.