Zn对Al_2O_3-Al-C滑板中温性能和显微结构的影响

以板状刚玉、氧化铝微粉、金属铝粉、金属锌粉为主要原料,以酚醛树脂为结合剂,制备Al_2O_3Al-C滑板样品。研究了金属锌粉的引入对Al_2O_3-Al-C滑板显微结构和性能的影响。结果表明:在450～1050℃热处理温度条件下,锌粉的引入改变了滑板中金属铝粉的反应进程,金属锌粉氧化后形成的氧化锌沉积在金属铝粉表面,改变了金属铝粉熔化、扩散和反应的进程,有利于材料在较低温度下形成金属结合,提高中温(600～1100℃)性能。锌粉的引入对材料显微结构有较大影响,900℃热处理3 h后材料内部形成大量颗粒状、柱状和针状氮氧化物,1 050℃热处理3 h后材料内部形成大量碳化铝纤维,有利于材料性能的提高。

EFFECT OF ADDING ZINC ON INTERMEDIATE-TEMPERATURE PROPERTIES AND MICROSTRUCTURE OF Al2O3-Al-C SLIDE GATE PLATE

Al2O3-Al-C slide gate plate samples were prepared using tabular alumina, alumina powder, aluminum powder, zinc powder as main starting materials and phenolic resin as a binder. The effects of zinc content on property and microstructure of Al2O3-Al-C slide gate plate heat treated at 450 to 1050 ℃ were investigated. The results show that the addition of zinc changes the reaction process of aluminum. Zinc reacts with oxygen to form zinc oxide, then deposits on the surface of aluminum, which can change the melting, diffusion and reaction rate of aluminum. This process is beneficial to Al2O3-Al-C slide gate plate forming a metal bond at a low temperature and increasing the property at intermediate temperature (600 to 1100 ℃). Zinc has a great impact on the microstructure of the materials. A large number of granular, columnar, needle-like nitride-oxides formed at 900 ℃ for 3 h, and many fibrous aluminum carbides formed at 1 050 ℃ for 3 h, which is favorable for the improvement of material performance.