关键词: 结合剂, 刚玉-尖晶石浇注料, 镍基高温合金, 抗侵蚀性能

Abstract: In order to expand the application of corundum-spinel materials in superalloy smelting,corundum-spinel strip specimens and crucible specimens were prepared using white fused corundum with particle sizes of 5-3,3-1,≤1 and ≤0.074 mm and sintered spinel with particle sizes of ≤1 and ≤0.044 mm as the main raw materials,active α-Al₂O₃ micropowder as the sintering aid,Secar 71 cement,ρ-Al₂O₃ micropowder or magnesium phosphate cement as the binder.The effects of different binders on the conventional properties and corrosion resistance to nickel-based superalloy of the specimens were researched.Among the three kinds of binders,the strip specimen with Secar 71 cement as the binder has optimal conventional performance and the lowest linear shrinkage rate after firing at 1 600 ℃.After the corrosion resistance test,the crucible specimen with Secar 71 cement as binder has the smallest macroscopic corrosion penetration area,the shallowest microscopic penetration depth,and the best corrosion resistance to nickel-based superalloy.The penetration of Cr into the crucible is shallow,and the penetration of Nb and Ti is obviously deeper than that of Cr,while the main components Ni and Fe hardly penetrate into the crucible specimens.

Key words: binder, corundum-spinel castable, nickel-based superalloy, corrosion resistance