摘要
以国内第2代单晶高温合金DD6为研究对象,研究了型壳中央散热对其凝固组织与持久性能的影响。结果表明,与合金中柱型壳相比,石墨中柱型壳能有效地改善单晶凝固过程中温度场的均匀性,提高温度梯度,有利于保持单晶凝固过程中热流方向的平直。因此,石墨中柱型壳有利于降低一次枝晶间距,细化γ-γ′共晶相,减少单晶生长方向与[001]方向的角度差,使单晶高温合金获得较高的持久寿命。
The influence of ceramic shell mold with central heat radiation on the microstructures and stress rupture property of DD6 single crystal superalloy was studied. The results indicate that the mold with graphite center pillar could improve the uniformity of the temperature field and the temperature gradient during the solidification, and it could straighten the direction of heat flow. As a result, the primary dendrite arm spacing decreases, the size and the volume fraction of γ-γ＇ eutectic decline, the angle between the single crystal growth orientation and the [001] orientation decreases, so the single crystal superalloy achieves a longer stress rupture life.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2016年第8期2057-2063,共7页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51202008)
中国博士后科学基金(2013M540037)
关键词
型壳中央散热
单晶高温合金
温度场
凝固组织
持久寿命
ceramic shell mold with central heat radiation
single crystal superalloy
temperature field
solidification microstructure
stress rupture life
