Si、Mn交互作用对一种Ni基合金凝固特性和力学性能的影响  

Influence of Si and Mn on Solidification Characteristics and Mechanical Properties of a Ni-Based Superalloy

作　　者：陆璐 倪家强 赵丹[1] 王常帅[2] LU Lu;Nl Jia-qiang;ZHAO Dan;WANG Chang-shuai(Shenyang Aircraft Company Limited,Shenyang 110850,Liaoning,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China)

机构地区：[1]沈阳飞机工业(集团)有限公司,辽宁沈阳110850 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《铸造》2021年第1期44-52,共9页Foundry

基　　金：国家自然科学基金(51971216,51301171);国家重大科技专项(2017-Ⅵ-0018-0090);国家能源局项目(NY20150102);“兴辽英才计划”项目(XLYC1807038)。

摘　　要：采用扫描电镜、电子探针等方法研究了Si、Mn交互作用对Ni基铸造高温合金IN625凝固特性和力学性能的影响。结果表明,Si、Mn均偏聚于枝晶间,粗化枝晶、增大Nb元素的枝晶偏析,却对Mo元素的偏析影响较小。与单独添加Si相比,同时添加Si、Mn进一步增大Si的枝晶偏析,但对Nb和Mn元素偏析影响较小,表明Mn显著影响Si的偏析行为,而Si对Mn的偏析无明显影响。Si促进γ/Laves共晶析出且其影响大于Nb元素,而Mn则对组成相无明显影响,同时含Si、Mn元素合金的凝固顺序与含Si合金相同,但γ/Laves共晶数量增加,被归因于Mn元素添加导致Si元素偏析的增大。Si、Mn对拉伸强度影响较小,但1.0wt.%Si、1.0wt.%Mn同时添加显著降低合金抗拉强度,随Si、Mn含量增加,断口表面韧窝减少,解离面增加,塑性降低。Influence of Si and Mn on the solidification characteristics and mechanical properties of a Ni-based superalloy was investigated by means of SEM, EPMA, DTA, TEM. The results show that Si and Mn segregate preferentially to the interdendritic regions, which increases the dendrite arm spacing and dendrite segregation of Nb, but only has negligible influence on the segregation of Mo. The combined addition of Si and Mn slightly increases the dendrite segregation of Nb and Mn, but obviously increases the dendrite segregation of Si. That is to say, Mn has obvious influence on the segregation behavior of Si. Further increasing the content of Si and Mn makes the dendrite segregation more serious. The phase transition route of the alloy without Si and Mn addition is determined as follows: L→L+γ→L+γ+MC→γ+MC. After Mn is added, the solidification sequence has no apparent change, but decreases solidus temperatures and slightly increases the amount of MC. The solidification sequence of the alloy containing Si is as follows: L→L+γ→L+γ+MC→ L+γ+MC+γ/Laves→γ+MC+γ/Laves, the as-cast microstructure are γ+MC+γ/Laves. The solidification sequence of the alloy containing Si and Mn is the same as that of the alloy only containing Si, but decreases the temperature of phase transition and obviously increases the amount of γ/Laves, but decreases the amount of MC. Si and Mn has slightly influence on the yield strength. However, the ultimate tensile strength obviously decreases after the addition of 1.0 wt.% Si and 1.0 wt.% Mn. The ductility gradually decreases with increasing Si and Mn content. The investigation of the fracture surfaces shows that the typical ductile fracture dimples decrease, but the cleavage fracture becomes obvious with increasing Si and Mn content.

关 键 词：NI基高温合金 凝固特性 力学性能 SI元素 MN元素 

分 类 号：TG146.2[一般工业技术—材料科学与工程]