DZ4高温合金的动态冲击压缩力学性能及修正J-C本构模型研究

    Dynamic Impact Compression Mechanical Properties and Modified J-C Constitutive Model of DZ4 Superalloy

    • 摘要: DZ4镍基高温合金主要用于制造航空发动机涡轮叶片、工作导片等核心高温部件。为了获取DZ4合金动态冲击压缩下的力学性能,并确定准确表征其动态力学行为的本构模型,本研究使用分离式霍普金森压杆系统,在25~900 ℃和1000~6000 s-1应变率下进行了动态冲击压缩试验,探讨了温度和应变率对DZ4合金应力-应变响应的敏感性。考虑应变-应变率-温度间的耦合作用,采用修正的J-C本构模型,以有效预测DZ4合金的塑性流动行为。结果表明:修正J-C本构模型的预测值与试验观察结果高度一致,其相关系数R为0.9768,平均相对误差MRE为2.16%,说明该模型能够准确描述DZ4合金在上述试验条件下的应力响应行为。

       

      Abstract: DZ4 nickel-based superalloy is primarily employed in the fabrication of critical high-temperature components such as turbine blades and working guide vanes for aero-engines. To obtain the mechanical properties of DZ4 alloy under dynamic impact compression and develop an accurate constitutive model for characterizing its dynamic mechanical behavior, dynamic impact compression tests were conducted using a split Hopkinson pressure bar (SHPB) system under temperature range of 25 ℃-900 ℃ and strain rate range of 1000 s-1-6000 s-1. The sensitivity of the stress-strain response of the DZ4 alloy to temperature and strain rate was discussed. A modified Johnson-Cook constitutive model was developed to effectively predict the plastic flow behavior of the DZ4 alloy. The results show that the modified J-C constitutive model accounts for the coupling effects of strain, strain rate and temperature. The model predictions exhibit a high degree of consistency with the experimental observations, with a correlation coefficient R of 0.9768 and a mean relative error (MRE) of 2.16%. It shows that the model can accurately characterize the stress response behavior of DZ4 alloy under the above test conditions.

       

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