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- Title
高应变率下GH4720Li合金热压缩性能研究.
- Authors
陈杰; 王志军; 张海峰; 徐永杰; 杨庆祥; 韩玉坤; 李磊
- Abstract
In order to study the dynamic mechanical properties of nickel base superalloy GH4720Li at a high strain rate, this paper carries out uniaxial thermal compression tests to the materials with a Split Hopkinson Pressure Bar(SHPB) in a temperature range of 20 ℃ to 1 000 ℃ and a strain rate range of 10 s-1 to 5 000 s-1. The stress-strain curves of the materials at different temperatures and different strain rates are obtained. The results show that under the same test temperature, GH4720Li alloy shows different dynamic mechanical properties at a high and a low strain rates. At a low strain rate(10 s-1), the stress value of GH4720Li alloy decreases with the increase of temperature. Under the condition of a high strain rate(1 000 s-1 or 5 000 s-1), the stress value of GH4720Li alloy increases with the increase of temperature in a specific temperature range(400 ℃ to 800 ℃). Combined with the obtained test data, the original Johnson-Cook (J-C) constitutive equation is modified by the numerical fitting method to meet the stress variation law of GH4720Li alloy at a high strain rate. The accuracy of the modified J-C constitutive equation is verified by linear correlation coefficient and mean error. The results show that the modified J-C constitutive equation is in good agreement with the experimental data, which can greatly improve the fitting accuracy of the J-C constitutive equation to the GH4720Li alloy in a large range of strain rates.
- Subjects
MATERIALS compression testing; STRESS-strain curves; HEAT resistant alloys; STATISTICAL correlation; ALLOYS
- Publication
Journal of Ordnance Equipment Engineering, 2023, Vol 44, Issue 5, p150
- ISSN
2096-2304
- Publication type
Article
- DOI
10.11809/bqzbgcxb2023.05.022