Ru含量对镍基高温合金铸态及热处理后组织的影响

Effect of Ru Content on the As-cast and Heat Treated Microstructure of Nickel-Based Superalloys

摘要:

对3种不同Ru元素含量的新型镍基高温合金铸态、热处理态的组织进行观察，研究了Re元素对合金凝固组织的特征及元素偏析行为的影响。结果表明：随着Ru元素含量（质量分数）的增加，合金γ′相的回熔温度及固相线温度（初熔温度）分别升高和降低，而液相线温度无显著变化；铸态合金组织的枝晶偏析明显，其枝晶干和枝晶间γ′相的尺寸及体积分数均呈下降趋势；铸态合金的主要强化元素的偏析，呈先升高后降低的趋势；经标准热处理后，合金中共晶组织消除，Ru元素含量的增加降低了合金的最高固溶处理温度。

Abstract:

The effects of Re on the solidification microstructure characteristics and elemental segregation behavior of three new nickel-based superalloys with different Ru contents were investigated in the as-cast and heat treated states， respectively. The results showed that with the increase of Ru content， the remelting temperature of the γ′ phase increases， the temperature of the solid phase line （initial melting temperature） decreases and the temperature of the liquid phase line does not change significantly. The dendritic segregation of the as-cast alloy was obvious， and the size and volume fraction of the γ′ phase between the dendrites and the interdendrites of the as-cast alloys decreased； the segregation of the main strengthening elements of the as-cast alloy firstly increased and then decreased. The average size and volume fraction of the γ′ phase between the dendrites and the interdendrites decreased. After the standard heat treatment， the eutectic microstructure was eliminated and the increase of Ru content reduces the maximum solution treatment temperature of the alloy.