试样尺寸对一种单晶高温合金组织的影响

Effect of Sample Size on Microstructures of a Single Crystal Superalloy

通过制备两种不同尺寸单晶试样的凝固试验,研究了试样尺寸对DD3单晶高温合金组织的影响。结果表明,在相同的凝固工艺条件下,试样尺寸增大,合金的一次枝晶间距和二次枝晶间距变大,合金元素的偏析程度稍有增加,枝晶干和枝晶间的铸态γ′相尺寸稍有增大,显微疏松无明显改变,共晶的尺寸和含量增加;经相同的热处理工艺处理后,试样尺寸增大,合金枝晶干和枝晶间的γ′相尺寸稍有增大。

The effects of sample size on the microstructure of DD3 single crystal superalloy were investigated.The results show that with the increasing of the sample size,the primary and secondary dendrite arm spacing increase,the extent of elements segregation is a little increase,the size of γ′ phase particles of dendritic core and indendritic slightly increases,the size and volume fraction of γ/γ′ eutectic increases,microporosity has no obvious change.After same heat treatment,the size of γ′ phase particles of dendritic core and indendritic slightly increases with the increasing of the sample size.