Preparation of graded porous titanium coatings on titanium implant materials by plasma spraying

Graded porous titanium coatings have been deposited on titanium substrates for dental implants by plasma spraying in an argon atmosphere. X-ray diffra ction (XRD), scanning electron microscopy (SEM), surface rough ness measure ment, and tensile strength tests were performed on graded porous coatings. The results showed that Ti3O5 was formed in the outermost surface of the po rous coatings due to oxidation. The graded porous coatings consisted of thr ee layers. The outer layer was full of macropores with a surface roughness of approximately 100 mu m. The diameter of many macropores reached and even surpassed 150 mu m, which could be beneficial for tissue to grow into the coating. The middle layer consisted of a mixture of micropores and macropor es. The inner layer was a very dense and tight interface layer that include d mechanical, physical, and metallurgical bonding. In tensile strength test s, testing bars peeled off the coatings, because the adhesive agent fractur ed, but the coatings remained intact. (C) 2000 John Wiley & Sons, Inc.