(上海大學(xué) 材料科學(xué)與工程學(xué)院，上海 200072)
摘 要: 研究縱向磁場(chǎng)對(duì)高溫合金DZ417G定向凝固顯微組織的影響。結(jié)果表明：在較低生長(zhǎng)速率下，磁場(chǎng)能顯著影響高溫合金柱狀枝晶的生長(zhǎng)；低磁場(chǎng)(＜0.1 T)能使枝晶生長(zhǎng)規(guī)則化，生長(zhǎng)方向逐漸統(tǒng)一并平行于磁場(chǎng)方向，一次枝晶臂間距減小；高磁場(chǎng)(＞2 T)破壞枝晶生長(zhǎng)，枝晶發(fā)生斷裂，逐漸出現(xiàn)一些云狀組織；隨著生長(zhǎng)速率的增大，磁場(chǎng)的影響逐漸減弱。并從磁場(chǎng)誘發(fā)熱電磁對(duì)流和熔體流動(dòng)影響枝晶生長(zhǎng)的角度對(duì)實(shí)驗(yàn)結(jié)果進(jìn)行分析。
關(guān)鍵字: Ni基高溫合金；縱向磁場(chǎng)；定向凝固；枝晶生長(zhǎng)行為
under longitudinal magnetic field
（Department of Materials Science and Engineering, Shanghai University, Shanghai 200072, China）
Abstract:The influence of longitudinal magnetic field on the microstructures of DZ417G superalloy at different growing rates was investigated. The results show that the magnetic field (＜0.1 T) can affect significantly the regular dendrite growth and primary dendrite arm spacing of DZ417G superalloy at low growing rate, and the growth direction is parallel to the direction of magnetic field. But the high magnetic field(＞2 T)can disturb the regular morphology of dendrite growth. The dendrite morphologies are destroyed when the magnetic field is applied. The effect of magnetic field is weak when the growing rate increases. Based on the theory of the influence of magnetic field on fluid, the above phenomenon was analyzed.
Key words: Ni-based superalloy; longitudinal magnetic field; directional solidification; dendrite growth behavior
