热变形对GH4169合金中NbC析出相尺寸形貌影响研究

Effect of Thermal Deformation on Size and Morphology of NbC Precipitates in GH4169 Alloy

摘要:

通过Gleeble3500热模拟试验机进行热压缩试验并结合微观组织观察和统计分析，研究了热变形对GH4169合金中NbC颗粒尺寸形貌、分布特征的影响规律。研究表明压缩过程中的绝热效应会导致试样心部温度的进一步升高，从而为变形过程中的NbC回溶提供条件。NbC颗粒与基体在变形过程中形成的高位错密度区促进了元素的扩散，并加速了小曲率半径的尖角区域回溶和钝化。随变形量的增加NbC回溶趋势增加，其平均尺寸与体积分数均呈降低趋势。变形过程金属流动会促进NbC颗粒的位移，在70%的变形量下，NbC颗粒平均间距增加趋势显著高于30%和50%变形量试样。因此随变形量的增加，NbC颗粒有从链状→链条弯曲→链条方向改变→弥散分布的分布特征，促进基体中原链状NbC呈细小、弥散分布。研究结果为GH4169闪光焊接性能的提高提供了直接的参考。

Abstract:

The thermal compression test was carried out by Gleeble 3500 thermal simulator and combined with microstructure observation and statistical analysis to study the effect of thermal deformation on the size and distribution characteristics of NbC particles in GH4169 alloy. Studies have shown that the adiabatic effect during compression leads to a further increase in the core temperature of the sample, thus providing conditions for NbC re-dissolution during the deformation process. The high dislocation density region formed by the NbC particles and the matrix during the deformation process promotes the diffusion of the elements and accelerates the remelting and passivation of the sharp corner regions with small radii of curvature. With the increase of deformation, the NbC remelting tendency increased, and the average size and volume fraction showed a decreasing trend. During the deformation process, the metal flow promotes the displacement of the NbC particles. Under the 70% deformation amount, the average spacing of the NbC particles increases significantly higher than the 30% and 50% deformation samples. Therefore, with the increase of deformation, the NbC particles have a distribution characteristic from chain→chain bending→chain direction→dispersion distribution, which promotes the fine and diffuse distribution of the original chain NbC in the matrix. The results provide a direct reference for the improvement of GH4169 flash soldering performance.