型壳中央散热对DD6单晶高温合金凝固组织与持久性能的影响  

Effects of Ceramic Shell Mold with Central Heat Radiation on Solidification Microstructure and Stress Rupture Property of DD6 Single Crystal Superalloy

作　　者：乐献刚[1] 周亦胄[2] 尚伟[1] 裴延玲[3] 顾欣[1] 孙长波[1] 

机构地区：[1]沈阳黎明航空发动机(集团)有限责任公司,辽宁沈阳110043 [2]中国科学院沈阳金属研究所,辽宁沈阳110016 [3]北京航空航天大学,北京100083

出　　处：《稀有金属材料与工程》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)

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.

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 

分 类 号：TG132.3[一般工业技术—材料科学与工程]