Calcium phosphate coatings: A comparative study between simultaneous vapor deposition and electron beam deposition techniques

A comparative study on calcium phosphate coatings produced by two different physical vapor deposition techniques namely, simultaneous vapor deposition (SVD) and electron beam deposition (EBD), has been carried out. All the as-deposited films were annealed at various temperature levels to achieve crystalline structure. The films produced were studied using X-ray diffraction and Rutherford backscattering spectroscopy. Surface morphological studies were conducted using scanning electron microscope. The structure and topography of both films were greatly affected by the annealing temperature. Apart from the prominent HAp phase, the coatings revealed minor phases of alpha tricalcium phosphate and tetracalcium phosphate. The EBD and SVD coatings recorded maximum bonding strength with the underlying substrates, on the coatings annealed at 1000 and 1200 °C, respectively. Differences detected between the two types of coated films emanate from the fact that they correspond to two different coating philosophies. This study reveals that both techniques have the potential to be alternative coating methods for biomedical implant devices.