【摘要】 用单边缺口拉伸试样研究了TiNi形状记忆合金在恒载荷下动态充氢时的滞后断裂过程,以及原子氢、氢致马氏体和氢化物在氢致滞后断裂中所起的作用.结果表明,TiNi合金能发生氢致滞后断裂,归一化门槛应力强度因子随总氢浓度对数的增加而线性下降,即KIH/KIC=2.01-0.25lnCT.在恒载荷动态充氢时氢化物含量不断升高,材料的断裂韧性不断下降,这是氢致滞后断裂的主要原因;而原子氢和氢致马氏体在氢致滞后断裂中所起的作用则极小.更多还原

【Abstract】 Hydrogen-induced delayed fracture during dynamic charging of TiNi shape memory alloy, and the role of atomic hydrogen, hydrogen-induced martensite and hydride in hydrogen-induced delayed fracture have been investigated. The results show that hydrogen-induced delayed fracture in TiNi alloy could occur, and the normalized threshold stress intensity factor decreased linearly with increasing the total hydrogen concentration, i.e., KIH/KIC=2.01-0.25 LnCT. The content of hydride increased continuously during dynamic charging, and the fracture toughness of the TiNi alloy decreased gradually, which is the main cause of hydrogen-induced delayed fracture. The role of atomic hydrogen and hydrogen-induced martensite in hydrogen-induced delayed fracture was very small.更多还原