Surface coating technology for biomaterials-morphology and nano-structure control

Thin film coatings have been widely employed, particularly in the semiconductor industry; however, thick oxide coatings also have promising applications including biomaterial coatings. High-speed deposition processes, commonly plasma spray or electron beam physical vapor deposition, have been utilized for thick coatings, whereas another deposition route has been pursued to obtain high-performance thick coatings. This paper introduces a new high-speed deposition process, laser chemical vapor deposition (LCVD), for thick coatings and its versatility of morphology and nano-structure control are advantageous to adherence of ceramic coatings to metal substrates. LCVD has achieved extremely high deposition rates ranging from 100 to 3000 μm/h for various oxide coatings such as ZrO₂, Y₂O₃, Al₂O₃ and TiO₂. Excellent adherence can be developed by columnar texture containing a large amount of nano-pores in the grain of oxide coatings.