郑亮 1肖程波 1张国庆 1顾国红 1李鑫 1刘晓光 1薛明 1唐定中1
作者信息
- 1. 北京航空材料研究院先进高温结构材料重点实验室,北京100095
- 折叠
摘要
Abstract
The interfacial reaction between alloy and ceramic core in equiaxed and directional solidified high Cr content cast Ni-base superalloy K4648 castings was systematically investigated by optical metallography (OM) , scanning electron microscopy (SEM) , energy dispersive spectroscopy ( EDS) , electron probe micro-analysis (EPMA) and X-ray diffraction (XRD). The kinetic curve which indicates the relationship between reaction time and amount was illustrated. The morphology of reaction interface and the reaction products at different time were also presented. The results shown that a severe interfacial reaction occurred between high Cr content cast Ni-base superalloy K4648 melt and silica-based core, whereas it did not happened to alumina-based core. The inner surface of the casting was destroyed due to the formation of the metallic abnormal knobs during the interface reaction. Furthermore, the color of silica-based core changed from the normal white to abnormal black. The black reacted region contained some metallic element from the alloy such as Cr, Al and Ti. It was noteworthy that the grey region distributed in the black reaction zone after long time reaction. The amounts of Cr, Al and Ti in the grey region were much higher than that in the black reacted zone. The interfacial reaction between K4648 alloy and silica-based core could be roughly divided into three stages: (1) The (Cr, Al, Ti) rich melts infiltration into ceramic cores. (2) The reaction between (Cr, Al, Ti) rich melts and SiO2 matrix in ceramic cores. (3) The reaction between (Cr, Al, Ti) rich melts and blocky ZrSiO4 in ceramic cores. Partially liquefaction appeared in the ceramic core region during the reaction. The main products of interfacial reaction between K4648 alloy and silica-based core were layer-shpe or dendritic A12O3) blocky intermetallic Cr3Si, ZrO2 (Cr,Zr,Al,Ti) rich oxides, eutectic (Cr,Si,Al,Ti) rich oxides, blocky or dendritic (Ti,Al,Zr, Cr) rich oxides. Among these reaction products, the elements Cr, Al and Ti were from the alloy melt and the Zr, Si and 0 from the ceramic core.关键词
镍基高温合金/陶瓷型芯/界面反应/定向凝固/显微组织/K4648/Cr3Si/Al2O3Key words
Ni-base superalloy/ ceramic core/ interfacial reaction/ directionally solidification/ microstructure/ K4648/ Cr,Si/A12O3分类
矿业与冶金
