Effects of Diamond-like Carbon Coatings with Different Thickness on Mechanical Properties and Corrosion Behavior of Biomedical NiTi Alloy

摘要:

采用电弧增强磁控溅射技术在生物医用NiTi合金表面沉积253~1880 nm厚的类金刚石涂层。用轮廓仪、划擦仪、摩擦磨损仪和电化学工作站等检测涂层的力学性能和腐蚀行为。结果发现，厚度在700 ~1000 nm之间的涂层具有较低的残余应力、较高的膜基结合力、长的磨损寿命和良好的耐腐蚀性。因此，更适合于作为生物医用NiTi合金的保护性涂层，同时也对NiTi合金表面类金刚石涂层的厚度对其力学性能和腐蚀行为的影响机制进行探讨。

Abstract:

Diamond-like carbon (DLC) coatings with the thickness between 253-1880 nm were prepared on NiTi alloy by arc enhanced magnetron sputtering (AEMS). Surface profilometry, scratch tests, tribometry, and electrochemical tests were conducted to determine the mechanical properties and the corrosion behavior of the DLC-coated NiTi alloy, and it is found that DLC coatings with thickness between 700 and 1000 nm have moderate residual stress, high critical load, long wear life and good corrosion resistance. So DLC coatings with thickness between 700 and 1000 nm are suitable for improving the mechanical properties and corrosion resistance of biomedical NiTi alloy. The associated mechanisms were also discussed in detail.