U-Ti合金的动态压缩性能及剪切特征

Dynamic Compression Performances and Adiabatic Shearing Characters of U-Ti Alloys

摘要:

采用分段式霍普金森杆（SHPB）及材料试验机测试200 ℃时效4 h的U-Ti合金在室温下的动静态压缩力学性能，采用扫描电镜和金相显微镜分析U-Ti合金动态压缩后的绝热剪切特征。结果表明，U-Ti合金是应变速率敏感材料，产生了应变速率强化效应；当应变速率为3600 s-1时，U-Ti合金已经发生45°剪切断裂；当应变速率达到5000 s-1时，U-Ti合金剪切断裂的同时产生烧蚀变形，剪切断口上出现塑性金属的韧窝特征；当应变速率为7300 s-1时，U-Ti合金45°剪切断面上出现了重熔现象。

Abstract:

The quasi-static and dynamic compression mechanical performances of the U-Ti alloys aged at 200 oC for 4 h were tested by a mechanical equipment and Split Hopkinson Pressure Bar (SHPB) at room temperature. The adiabatic shearing characters of U-Ti alloys after dynamic compression were analyzed by SEM and OM. The results show that the U-Ti alloys are sensitive to strain rate because there is strengthening effect of strain rate. The 45o shear fracture had been yielded in the U-Ti alloys at the strain rate of 3600 s-1. Both the 45o shear fracture and ablative deformation were observed in U-Ti alloys when the strain rate reached 5000 s-1. Refusion phenomenon was found on the 45o fracture surface at the strain rate of 7300 s-1. The fracture morphology exhibits dimple character of plastic metal.