铸型温度对单晶高温合金叶片凝固组织的影响  

Influence of Mould Temperature on Solidification Microstructure of Single Crystal Superalloy Blade

作　　者：史振学[1] 刘世忠[1] 韩梅[1] 李嘉荣[1] 

机构地区：[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

出　　处：《钢铁研究学报》2014年第9期48-52,共5页Journal of Iron and Steel Research

摘　　要：在高温度梯度真空定向凝固炉中,采用螺旋选晶法通过3种不同铸型温度分别制备了[001]取向的DD6单晶高温合金叶片,利用光学显微镜和扫描电镜观察了不同工艺条件下合金的铸态组织,研究了铸型温度对单晶高温合金凝固组织的影响。结果表明,随着铸型温度的升高,合金的一次枝晶间距和二次枝晶间距变小,合金元素的偏析程度降低,枝晶干和枝晶间的铸态γ′相尺寸减小,共晶的尺寸和含量稍有减小,显微疏松的尺寸和体积分数稍有减小。DD6single crystal superalloy blade with [001]orientation was cast at three mould temperatures by means of crystal selection method in a directional solidification furnace with high temperature gradient.The microstructures of the alloy with different mould temperature were investigated by OM and SEM.The influence of mould temperature on the solidification microstructure of DD6 single crystal superalloy blade were investigated.The results show that with the increasing of the mould temperature,the distances between primary dendrite arms or secondary dendrite arms decrease,the segregation extents of elements in the alloy decrease,the sizes ofγ′phase particles at dendrite core and between dendrite arms slightly decrease,and the size and volume fraction ofγ/γ′eutectic and microporosity slightly decrease.

关 键 词：单晶高温合金 叶片 铸型温度 组织 

分 类 号：TG24[金属学及工艺—铸造] TG132.3[一般工业技术—材料科学与工程]