Evaluation of Treatment Effect and Mechanism Analysis of Ti6AL4V Porous Scaffolds Prepared by Selective Laser Melting with Different Chemical Polishing Processes.

The large amount of unfused powder that remains on the surface of Ti6AL4V porous scaffolds prepared by selective laser melting technology is a common problem. Therefore, this article investigated the effects of three different chemical polishing processes on the surface state, pore structure, and mechanical properties of small pore size scaffold materials at different polishing times in the field of implantable medical devices. The results show that the overall treatment effect of the simple chemical polishing process is poor, the internal treatment depth of porous support is insufficient and uneven, and the overall mechanical properties of the sample with the same porosity are average. The outer structure during the electrochemical polishing process showed an obvious treatment effect. However, the internal treatment depth and uniformity were significantly lower compared with the simple chemical polishing process, and the overall mechanical properties of the sample with the same porosity were inferior. The overall treatment effect, depth, and uniformity of the inner and outer structure of the sample using a dynamic chemical polishing process were significantly optimized, and the overall mechanical properties of the sample with the same porosity were superior to the other two methods. Furthermore, the main reasons for the nonuniform treatment effect between the inner and outer layers during the chemical polishing of porous scaffolds were observed to be related to the restricted exchange of etchant caused by the complex internal structure of porous scaffolds and the gas generated by the chemical reaction.