Mechanical properties of a dental ceramic coated by RF magnetron sputtering

Metal and ceramic thin film coatings were deposited onto a dental ceramic via radio frequency (RF) magnetron sputtering. The objectives of the study were to determine if a coherent interface could be produced between the coating and the substrate and if the coating significantly would improve the mechanical properties of the ceramic. Thin films of Au, Al, and AlN were deposited in this study. Mechanical testing results indicated that a significant improvement in flexural strength was observed with both Au and Al coatings while significant improvements in the flexural modulus were observed with all three materials. SEM analysis indicated that the interfaces were coherent and also suggested two mechanisms (crack bridging and crack blunting) that could be responsible for the enhanced mechanical properties.