【摘要】 将自制的25kg级BaZrO3坩埚用于Ti-55.8%Ni合金(质量分数)的真空感应熔炼,并将合金铸锭经锻造、轧制、拉拔等工序制成φ1.0mm的TiNi合金丝材,取样经不同的制度热处理后,分析了TiNi合金丝材的拉伸性能、低周弯曲疲劳性能以及拉伸、疲劳断口形貌。结果表明:丝材经700℃保温1h水淬处理后,延伸率可达23%,韧窝尺寸变小、数量增多,且微孔数量大幅减少。此外,丝材经500℃或550℃保温20min水淬处理后,疲劳寿命得到提高,最高可达3072次,疲劳断口处贝纹线排列紧密,裂纹较短且部分存在分叉现象。更多还原

【Abstract】 Ti-55. 8wt% Ni alloy ingot was prepared by vacuum induction melting in 25 kg-grade home-made Ba Zr O3 crucible,and the ingot was turned into φ1. 0 mm wire by forging,rolling,drawing and etc. For the Ti Ni wire samples followed by different heat treatments,their tensile properties,low cyclic bending fatigue behaviors,fractographies and fatigue fractography morphologies were analyzed. The results show that,after water quenching at 700 ℃ for 1 h,the elongation of samples can reach 23%,and the sizes of dimples become smaller,while the numbers of dimples and micropores are shrink. Besides,after water quenching at 500 ℃ or 550 ℃ for 20 min,the fatigue life of samples is improved,which can reach 3 072 times. Cowrie pattern lines of fatigue fractographies are arrayed closely,and cracks in the matrix are small and part of the cracks are bifurcate.更多还原