摘要
在液氮温度和室温下对商业纯钛采用不同的压下量进行轧制,并进行真空退火处理。对试样进行单轴拉伸实验和硬度实验研究其力学性能,采用光学显微镜和扫描电子显微镜研究其微观组织和断口形貌,通过电化学实验研究其耐腐蚀性能。结果表明,冷轧可以显著提升商业纯钛的抗拉强度,变形量为90%时可由原始态的281. 4 MPa提升至848. 4 MPa;断裂伸长率由16. 0%降至4. 0%。同时在80%的变形量下,深冷轧制强度(794. 3 MPa)比室温轧制的抗拉强度(691. 8 MPa)更高。随着变形量的增加,断口形貌显示试样由韧性断裂向脆性断裂转变。退火后发生再结晶,硬度大幅度降低,深冷轧制相对室温冷轧的增强强化效果消失。在人工模拟体液中进行开路电位、极化曲线与电化学阻抗谱测试。结果表明,退火使腐蚀电位负移,腐蚀电流密度增大,电荷转移极化电阻减小,退火后纯钛晶粒长大,耐腐蚀性降低。
Commercial pure titanium(CP Ti)was rolled at liquid nitrogen temperature(LT)and room temperature(RT)under different reductions,and vacuum annealed.The microstructure and fracture morphology were investigated by optical microscope(OM)and scanning electron microscope(SEM),the mechanical properties were investigated by uniaxial tensile tests and hardness tests,and the corrosion resistance properties were fully investigated by electrochemical tests.The results suggest that the tensile strength of CP Ti increases obviously from 281.4 to 848.4 MPa at 90%deformation reduction while the elongation decreases from 16.0%to 4.0%.At 80%deformation reduction,the tensile strength of CP Ti is higher at LT(794.3 MPa)than that at RT(691.8 MPa).As deformation reduction increases,the fracture morphology shows that the sample changes from ductile fracture to brittle fracture.The sample recrystallizes after annealing,and the hardness decreases obviously,and the enhanced strengthening effect in LT samples disappeares compared with RT samples.The open circuit potential(OCP),polarization curve(PC),electrochemical impedance spectroscopy(EIS)electrochemical test were performed in simulated body fluid.The results show that after annealing,the positive corrosion potential decreases,the corrosion current density increases,and the charge transfer resistance decreases.Because of grain growth of pure titanium after annealing,the corrosion resistance properties decrease.
作者
方劲
刘芳
第文琦
许光丽
崔权
FANG Jin;LIU Fang;DI Wen-qi;XU Guang-li;CUI Quan(School of Materials Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期98-105,共8页
Journal of Plasticity Engineering
基金
上海理工大学大学生创新创业训练计划资助项目
关键词
商业纯钛
冷轧
退火
力学性能
微观组织
断口形貌
耐腐蚀性能
commercial pure titanium
cold-rolling
annealing
mechanical properties
microstructure
fracture morphology
corrosion resistance properties
