Si_3N_4-SiC陶瓷材料的抗铜侵蚀性能

Corrosion resistance to copper of Si_3N_4-SiC ceramics

采用坩埚法研究了Si3 N4-SiC陶瓷材料在空气气氛中的抗铜侵蚀性能 ,侵蚀温度为 1130℃ ,时间为 2 5h ;选用铜熔炼用Si3 N4-SiC陶瓷塞棒在工厂实际生产环境中进行氮气气氛中的抗铜侵蚀试验 ,试验温度为 1130～ 115 0℃ ,时间是 4 0 0h。试验完成后 ,用XRD分析坩埚试样侵蚀层的相组成 ,用扫描电子显微镜观察坩埚试样侵蚀层的显微结构。结果表明 :在氮气气氛中 ,铜熔体含氧量低 ,Si3 N4-SiC材料具有优异的抗侵蚀性能。空气气氛中 ,铜熔体含氧量高 ,Si3 N4-SiC材料的抗侵蚀性能差。这是由于铜熔体中存在大量的Cu2 O ,促使Si3 N4快速氧化 ,生成SiO2 、N2 和Cu ,SiO2 熔入铜熔体中所致。

The corrosion resistance of the Si 3N 4-SiC ceramics to molten copper in air was studied by crucible method at 1130 ℃ for 25 h,and the corrosion resistance test in N 2 atmosphere was conducted using the Si 3N 4-SiC stopper for copper smelting in actual production condition at 1130～1150 ℃ for 400 h.The phase composition and microstructure of corrosion layer of the attacked specimen was examined by XRD and SEM.The conclusions are as follows:In nitrogen atmosphere,oxygen content in molten copper is low,so the corrosion resistance to molten copper of Si 3N 4-SiC ceramics is excellent;In air,oxygen content in molten copper is high,corrosion resistance of Si 3N 4-SiC ceramics is poor.In molten copper,there is a lot of Cu 2O,which can oxidize Si 3N 4 rapidly forming SiO 2,N 2,and Cu,and SiO 2 melt into copper melt,resulting in poor corrosion resistance of Si 3N 4-SiC ceramics in air.