论文部分内容阅读
研究重熔料及稀土钇对ZL205A合金铸态组织、热裂性能及凝固特性的影响。结果表明:单独和复合添加重熔料及稀土钇都能够细化合金组织,使之变得更加均匀、细小。单独添加重熔料对ZL205A合金相的组成没有影响,但是提高了ZL205A合金凝固过程中液相线温度,增大了固液共存区间,进而增加合金的热裂倾向性;单独添加稀土钇和复合添加重熔料及稀土钇均可使合金凝固过程中液相线温度降低,减小固液共存区间从而有效地改善合金的热裂倾向性,使得热裂抗力由原料ZL205A合金的330N左右分别提高至450和670N左右。除此之外,添加稀土钇后,三角晶界处出现了灰色块状富钇相。
The effects of remelting and rare earth yttrium on the as-cast microstructure, thermal cracking and solidification properties of ZL205A alloy were studied. The results show that both the remelt and the rare earth yttrium can be refined into fine and homogeneous alloy by both single and composite addition. The addition of remelting alone had no effect on the composition of the ZL205A alloy, but increased the liquidus temperature during the solidification of ZL205A alloy and increased the coexistence of solid and liquid zones, which in turn increased the hot cracking tendency of the alloy. Separate addition of rare earth yttrium and composite The addition of remelting material and rare earth yttrium can decrease the liquidus temperature during the solidification of the alloy and reduce the coexistence of solid and liquid so as to effectively improve the hot cracking tendency of the alloy and increase the thermal cracking resistance from about 330N of the starting material ZL205A 450 and 670N or so. In addition, after the addition of rare earth yttrium, the gray massive yttrium phase appears in the triangular grain boundaries.