Development of titanium wire ropes for implantable stimulation electrode and their evaluation

1.植入式刺激电极用钛耐磨材料的研制(1)α+β钛合金Ti-4.5Al-6Nb-2Fe-2M拉丝，直径100μm。阳极氧化对拉丝表面氧化物的生成是有效的。在常压氧化生成氧化物的过程中，建议采用低温工艺。(2)将β钛合金拉伸到直径为42μm的线材上。采用低温大气氧化的方法在表面形成氧化物。此外，利用阳极氧化将β类合金拉伸至直径100μm，拉拔后表面光滑。(3)将Cp钛(4N)拉伸至直径47μm的线材上。该线材的表面形态优于市售的直径46μm的CP钛线材。(4)将α钛合金拉伸制得直径为51μm的Cp钛合金线材，具有良好的表面光洁度和力学性能。研制成功了7股、7股、7股、7股、7股的钛合金钢丝绳。评价(1)直径为47μm的CP钛丝的最大抗拉强度和总延伸率分别为980 Mpa和3.5%。测试了β钛合金线材和α钛合金线材的力学性能。(2)研制的直径为47μm的CP钛合金线材和市售的直径为46μm的CP钛合金线材的疲劳极限分别为2 0 0 Mpa和30 0 Mpa。疲劳极限的差异可能是由疲劳试验后的表面粗糙度引起的。经10^7次循环后，市售CP钛丝的表面比已开发的CP钛丝表面光滑。

1. Development of titanium wore for implantable stimulation electrodes(1) α+β type Ti-4.5Al-6Nb-2Fe-2M titanium alloy was drawn to the wire with 100 μm in diameter. Anodic oxidation was effective to the oxide formation on the surface for wire drawing. In the atmospheric oxidation for oxide formation process, it was suggested that the low temperature process was preferred.(2) β type Ti-14Mo-3Nb-1.5Zr titanium alloy was drawn to the wire with 42 μm in diameter. The low temperature atmospheric oxidation was used for oxide formation process on the surface. In addition to that, the β type alloy was drawn to 100 μm in diameter using anodic oxidation, which showed the smooth surface after drawing.(3) CP titanium (4N) was drawn to the wire with 47 μm in diameter. The surface morphology of this wire was better than that of commercially available CP titanium wire with 46 μm in diameter.(4) α type Ti-10Zr titanium alloy was drawn to the wire with 51 μm in diameter, which exhibited the excellent surface smoothness and mechanical properties. The wire ropes with 7 and 7x7 strands made of Ti-10Zr titanium alloy were successfully developed.2. Evaluation(1) The maximum tensile strength and total elongation of CP titanium wire with 47 μm in diameter were 980 MPa and 3.5 %. The mechanical properties of the β type Ti-14Mo-3Nb-1.5Zr titanium alloy wire and the α type Ti-10Zr titanium alloy wire were measured.(2) The fatigue limits of the developed CP titanium wire with 47 μm in diameter and commercially available CP titanium wire with 46 μm in diameter were 200 MPa and 300 MPa, respectively. The difference of fatigue limit may be caused by the surface roughness after fatigue testing. The commercially available CP titanium wire exhibited the smoother surface than developed CP titanium wire after 10^7 cycles.