摘要
Abstract
Objective To explore the effects of Ti coating thickness and spraying frequency on the fatigue strenght of implants,so as to provide theoretical basis for determining coating thickness and controlling spraying process.Methods A vertically downward load was applied to 300-and 600-μm-thick titanium-coated Ti-6Al-4V alloy substrate specimens until the test was stopped at the drop of the load according to the requirements of ASTM F1 160-14,with the maximum ultimate load of each specimen during the test recorded and the bending stresses deduced.The maximum bending stress values against bending fatigue were obtained by applying 107 times of vertically downward cyclic loads in a sinusoidal waveform to the 2 specimens to determine the effect of different titanium coating thicknesses on the fatigue strength of the specimens.According to the requirements of ISO 7206-4:2010 120-1200 N cyclic loads were applied to the femoral shafts of the alloy substrates after one time and two times of coating,and the fracture situations of the shafts and the numbers of cyclic fatigue tests in case of the fracture were recorded so as to determine the effects of Ti coating thickness on the fatigue strength of implants.Results The maximum beding stress of 600-μm-thick titanium-coated Ti-6Al-4V alloy substrate specimen showed no significant differences with that of 300-μm-thick coated specimen(P＞0.05),which was only lower than the latter by 1.5％after applying 107 times of vertically downward cyclic loads;under 120-1200 N cyclic loads,none of the three femoral shafts with one time of Ti coating fractured after 500 millon times of cyclic loading,while the three femoral shafts with two times of Ti coating fractured at cycles up to 180 000,300 000 and 2.3 million cycles,respectively.Conclusion There is no significant difference between 300-and 600-μm-thick titanium-coated Ti-6Al-4V alloy substrate specimens in fatigue strength;the femoral shaft with two times of Ti coating has the fatigue resistance decreased significantly when compared with the shaft with one time of coating.[Chinese Medical Equipment Journal,2024,45(6):38-43]关键词
植入物假体/钛涂层厚度/喷涂频次/疲劳性能/Ti-6Al-4V合金基体Key words
implant/Ti coating thickness/spraying frequency/fatigue strength/Ti-6Al-4V alloy substrate分类
医药卫生
