固溶温度对DD416镍基单晶高温合金组织及拉伸性能的影响

Effect of solution temperature on microstructure and tensile properties of DD416 nickel⁃based single crystal superalloy

研究了固溶处理温度对一种高强低密度第一代的镍基单晶高温合金DD416的组织及拉伸性能的影响。结果表明,铸态试样中存在着明显的成分偏析与元素偏析现象。经过固溶处理后,合金中的成分偏析与元素偏析现象得到明显改善,随着固溶温度的提高,合金中的共晶组织含量逐渐减少。铸态合金中存在的孔洞为铸造疏松,在经过固溶处理后,由于元素扩散速率的不同会出现小部分的固溶孔洞,合金中空洞较多也会影响合金性能。通过对760℃高温拉伸数据可以看出,合金的拉伸性能在经过热处理后得到较为明显的提高,随着固溶温度的提高,合金的抗拉强度和屈服强度有所提高,合金的断后伸长率和断面收缩率也有着较为显著的增加,即经过固溶处理+时效处理后,随着固溶温度的提高,合金的强度与塑性得到改善与提高。

Effect of solution treatment temperature on microstructure and tensile properties of the first generations nickel⁃based single crystal superalloy DD416 with high strength and low density was studied.The results show that there are obvious component segregation and element segregation in the as⁃cast specimens.After solution treatment,the component segregation and element segregation in the alloy are obviously improved.With the increase of solution temperature,the content of eutectic structure in the alloy decreases gradually.The pores in the as⁃cast alloy are cast porosity.After solution treatment,a small number of solution pores appear due to the different diffusion rates of elements,and many hollow pores in the alloy also affect the properties of the alloy.According to the 760℃high temperature tensile data,the tensile properties of the alloy are significantly improved after complete heat treatment.With the increase of solution temperature,the tensile strength and yield strength of the alloy increase,and the elongation after fracture and the percontage reduction of area significantly increase.As a result,after solution treatment+aging,with the increase of solution temperature,the strength and plasticity of the alloy are improved.