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通过组织形貌观察及蠕变曲线测定,研究了一种含Re镍基单晶合金的高温蠕变行为。结果表明:含4.2%Re单晶合金在1060-1100℃温度区间具有较好的承温能力,但表现出较强的施加应力敏感性。经高温蠕变断裂后,在试样不同区域γ′相具有不同的组织形貌,在远离断口区域γ′相形成的筏状组织与施加应力轴方向垂直,而在近断口区域,筏状γ′相的粗化及扭曲程度的增大为该区域发生较大塑性变形所致。在蠕变后期,合金的变形机制是迹线方向为[011]和[011]的滑移位错切入筏状γ′相,主、次滑移系交替开动,使筏状γ′相发生扭折形成不规则的扭曲形态,直至发生断裂是合金的蠕变断裂机制。
The high temperature creep behavior of a Re-containing nickel-based single crystal alloy has been investigated by microstructure and creep curve. The results show that the 4.2% Re single crystal alloy has good temperature-bearing ability in the temperature range of 1060-1100 ℃, but shows a strong sensitivity to applied stress. After high temperature creep rupture, the γ ’phase has different microstructure in different regions of the sample, and the raft structure formed in the γ’ phase away from the fracture region is perpendicular to the direction of the applied stress axis. In the near fracture region, the γ The coarsening and distortions of the phase lead to larger plastic deformation in this area. At the late stage of creep, the deformation mechanism of the alloy is that the slip dislocations with the trace directions of [011] and [011] are cut into the raft γ ’phase and the primary and secondary slip systems are alternately activated to make the raft γ’ phase twist Fold into irregular twisted form, until the occurrence of fracture alloy creep rupture mechanism.