Clemson-MUSC Bioengineering Program, Charleston, South Carolina.
Department of Bioengineering, Clemson University, Clemson, South Carolina.
J Orthop Res. 2020 Jul;38(7):1617-1626. doi: 10.1002/jor.24681. Epub 2020 Apr 13.
Fretting corrosion at the head-neck taper junction was compared between silicon nitride (Si N ) and commercially available cobalt chrome (CoCrMo) femoral heads on titanium (Ti-6Al-4V) trunnions. An electrochemical setup was used to capture the fretting currents (characterized by oxide abrasion and repassivation) during cyclic loading. Onset load, pull-off force (disassembly load), short term and long term (1 million cycles) fretting currents were used to compare the fretting corrosion performance between the test group (Si N /Ti-6Al-4V) and the control group (CoCrMo/Ti-6Al-4V). Incremental cyclic fretting corrosion tests showed that the Si N /Ti-6Al-4V combination had statistically lower (P < .05) average fretting current of 0.189 µA (SD = 0.114 µA) compared to 0.685 µA (SD = 0.630 µA) for CoCrMo/Ti-6Al-4V for cyclic load of 3200 N. Similarly, for the one million cycle fretting corrosion tests, the Si N /Ti-6Al-4V couples had statistically lower (P < .05) average current (0.048 µA, SD = 0.025 µA) vs CoCrMo/Ti-6Al-4V couples (0.366 µA, SD = 0.143 µA). The Si N heads also had higher onset loads (P < .05) for fretting (vs CoCrMo, 2200 N vs 1740 N) indicating a difference in surface contact mechanics between the two groups. Scanning electron microscopy with energy dispersive spectroscopy confirmed material transfer from the trunnions to the heads for both groups tested, and from head to trunnion for the CoCrMo heads. Minimal Si N transfer was noted. The electrochemical, mechanical, and microscopic inspection data supported the hypothesis that Si N /Ti-6Al-4Vcombination had better fretting corrosion performance compared to CoCrMo/Ti-6Al-4V.
在钛（Ti-6Al-4V）轴颈上比较了氮化硅（SiN）和市售钴铬（CoCrMo）股骨头在头-颈锥度交界处的微动腐蚀。电化学装置用于捕获循环加载过程中的微动电流（特征为氧化物磨损和再钝化）。起始载荷、拔出力（拆卸载荷）、短期和长期（100 万次循环）微动电流用于比较实验组（SiN/Ti-6Al-4V）和对照组（CoCrMo/Ti-6Al-4V）的微动腐蚀性能。增量循环微动腐蚀试验表明，与 CoCrMo/Ti-6Al-4V 相比，SiN/Ti-6Al-4V 组合的平均微动电流显着降低（P<0.05），为 0.189µA（SD=0.114µA），循环载荷为 3200N。同样，对于一百万次循环的微动腐蚀试验，SiN/Ti-6Al-4V 对的平均电流（0.048µA，SD=0.025µA）显着低于 CoCrMo/Ti-6Al-4V 对（0.366µA，SD=0.143µA）（P<0.05）。SiN 头的微动起始载荷也更高（P<0.05）（与 CoCrMo 相比，2200N 与 1740N），表明两组之间的表面接触力学存在差异。带有能量色散光谱的扫描电子显微镜证实，两种测试组的材料都从轴颈转移到了头部，而 CoCrMo 头的材料则从头部转移到了轴颈。注意到很少的 SiN 转移。电化学、机械和微观检查数据支持 SiN/Ti-6Al-4V 组合的微动腐蚀性能优于 CoCrMo/Ti-6Al-4V 的假设。
