(南昌航空大學 航空制造工程學院，南昌 330063)
摘 要: 采用真空差壓鑄造技術在不同凝固壓差下制備ZL114A合金試樣，通過金相、掃描電鏡、高溫蠕變性能測試等技術考察凝固壓差對真空差壓鑄造ZL114A合金初生相組織、共晶硅形貌和高溫蠕變性能的影響。結果表明：隨著凝固壓差的增大，合金的初生相組織得到明顯細化，由粗大的樹枝晶轉變?yōu)榧毿〉牡容S晶，共晶硅形貌也由粗大的針狀向短棒或顆粒狀轉變；同時ZL114A合金的高溫蠕變性能得到顯著改善；當凝固壓差為90 kPa時，其蠕變時間達到100 h后合金試樣仍未見斷裂，此時試樣的變形量僅為0.21%。
關鍵字: ZL114A合金；真空差壓鑄造；凝固壓差；微觀組織；高溫蠕變
（School of Aeronautic Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:ZL114A alloy samples were prepared by vacuum counter-pressure casting technique under different solidification pressure differences. The effects of solidification pressure difference on the primary phase structure, eutectic silicon morphology and high temperature creep properties of vacuum counter-pressure casting ZL114A alloy were investigated by metallography, SEM and high temperature creep performance tests. The results show that as the solidification pressure difference increases, the primary phase structure of the alloy is remarkably refined from coarse dendrites to fine equiaxed crystals, and the eutectic silicon is also transformed from a coarse needle shape to a small short rod or granular shape. At the same time, the high temperature creep property of ZL114A alloy is significantly improved. When the solidification pressure difference is 90 kPa, the alloy sample still has no fracture after the creep time reaches 100 h. At this time, the deformation of the sample is only 0.21%.
Key words: ZL114A alloy; vacuum counter-pressure casting; solidification pressure differences; microstructure; high temperature creep
