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高温下多主元合金的动态变形行为与本构建模OA北大核心CSTPCD

Dynamic deformation behavior and constitutive modeling of multi-component alloys at high temperature

中文摘要英文摘要

为加速多主元合金在航空工业领域的应用,将航空发动机经常面临的高温高应变率耦合环境作为实验条件,在5种温度下开展了CoCrFeNiMn多主元合金的动态压缩实验和变形后试样的塑性变形机理微观表征.结果表明:在1273 K的高温环境中,多主元合金的动态屈服强度可达200 MPa,表现出较好的耐高温性能;随着动态塑性应变的增加,材料内部出现了晶粒粗化的现象,并且在晶界处具有更高的亚结构孕育能力.此外,量化了不同环境温度下动态塑性变形过程中绝热温升的变化规律,指出了现有动态本构关系对CoCrFeNiMn多主元合金在宽温度域内动态应力-应变关系预测能力的不足.最后,通过解耦分析初始屈服与塑性流动阶段的温度效应,建立了一个指数形式的唯象动态本构方程.该本构方程可用于预测冲击载荷作用下宽温度域内多主元合金的屈服强度和塑性流动规律.

Compared to traditional alloys,the new multi-component alloy exhibits an excellent "cocktail effect". This effect allows for the collaborative control of structure and performance,making it highly suitable for application in the demanding service environment of the aviation industry. Experimental conditions simulating high temperature and high strain rate coupling environments encountered by aero engines are employed to expedite the adoption of multi-principal component alloys in the aviation industry. Using the CoCrFeNiMn multi-principal element alloy as the research object,dynamic impact tests were conducted at different temperatures (298,673,873,1073,1273 K) by using a split Hopkinson pressure bar with an impact velocity of 20 m/s. Dynamic stress-strain curves at five temperatures were obtained,and the results indicate that the stress-strain curve at 1273 K has higher strain-hardening ability compared to 873 K and 1073 K. When the temperature increases to 1273 K,the material's yield strength can still reach 200 MPa,demonstrating good high-temperature performance.The grain size,dislocation density,and microstructure types of the samples before and after deformation were discussed by electron backscatter diffraction tests. The experiment result reveals that an increase in dynamic plastic strain at 1273 K leads to a grain coarsening phenomenon,with higher substructure breeding ability observed at the grain boundary. In addition,the change in adiabatic temperature rise and ambient temperature during dynamic plastic deformation is quantified. It is also highlighted that the current dynamic constitutive relationship is inadequate in predicting the dynamic stress-strain relationship of the CoCrFeNiMn multi-principal component alloy across a wide temperature range. Finally,an exponentially phenomenological dynamic constitutive equation is established by decoupling the temperature effect between the initial yield and the plastic flow stage. This constitutive equation allows for accurate prediction of the yield strength and plastic flow behavior of multi-component alloys under impact loads over a wide temperature range.

邱吉;苏步云;金涛;姚小虎;树学峰;李志强;方慧青

太原理工大学航空航天学院,山西太原 030024||华南理工大学土木交通学院,广东广州 510641||山西省建设投资集团有限公司,山西太原 030032太原理工大学机械与运载工程学院,山西太原 030024华南理工大学土木交通学院,广东广州 510641太原理工大学航空航天学院,山西太原 030024

力学

高温高应变率耦合塑性变形机理动态本构关系绝热温升多主元合金

high temperature and high strain rate couplingplastic deformation mechanismdynamic constitutive relationadiabatic temperature risemulti-component alloy

《爆炸与冲击》 2024 (007)

1-11 / 11

国家自然科学基金(12302477,12272255,12272256);山西省基础研究自由探索项目(202203021222081)

10.11883/bzycj-2023-0439

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