Research On The Dual-motion Fretting Corrosion Characteristics Of Pure Titanium And Ti6Al4V Alloys In Saline And Hank's Solutions

Metal implanted materials are subjected to wear and corrosion damage because of the effect of contact Mechanics and body's medium factors.Clinical practice showed that the fretting corrosion has become one of the primary damage to metallic implants.Most of studies from civil and abroad are focused on that various factors affect fretting corrosion of metallic implants, and the researchs method mostly use single loading, whereas few investigations have been done on the combination of radial and tangential fretting.The dual-motion fretting corrosion tests on ball-on-flat contacts of TA2/TA2 and Ti6A14V/TA2 have been carried out under deionized water, saline solution and Hank's solution.The kinetic behaviours of the dual-motion fretting corrosion tests were analyzed in combination with microscopic examinations through optical microscope, laser confocal scanning microscopy (LCSM) and scanning electrical microscope (SEM). The following conclusions were obtained.1.The F-D curves of two materials presented two types, i.e. the qusi-trapezoidal and elliptical in three mediums after fifty thousand,and the duration of the qusi- trapezoidal was less than ten cycles.There are no linear cycle in test conditions.The vertical displacement increased with the increase of load.The displacement in saline solution was larger than that of in Hank's solution and deionized water for the same material.The displacement of TC4 alloy was smaller that of TA2 in the first cycle.During the running-in period of the dual- motion fretting,the dissipated energy decreased rapidly with the cycle number increasing.After that,the dissipated energy decreased slowly and keep stable finally.3.The damage of two materials was slight when the load was small.The wear morphology of TC4 alloy had annular morphology,while the annular morphology of TA2 was not obvious.The fretting wear mechanisms of two materials exhibited mainly abrasive wear and delamination mechanism in three media.4.The volume-loss was bigger in medium than that of in air. The volume-loss was the biggest in saline solution and the smallest in deionized water. The volume-loss of TC4 alloy was smaller that of TA2.