Numerical simulation of hydroxyapatite powder behaviour in plasma jet

The paper deals with numerical simulation of hydroxyapatite (HA) coating deposition by plasma spraying. The velocity and temperature fields of Ar+N2 plasma generated by a commercial plasma torch of given power at atmospheric pressure are calculated in three-dimensional with the use of GENMIX numerical code. The HA powder particles granulometry and internal morphology were characterized with the use of laser sizer and scanning electron microscope, respectively. The image analysis enabled to determine the internal porosity of powder particles manufactured by the spray-drying method. The physical and thermophysical data of HA as a function of temperature were collected from literature sources. The HA particles injection velocity into the plasma jet was calculated analytically. The trajectories and temperatures fields inside these particles were calculated numerically using Plasma 2000 code. These fields determined at experimental spray distance, were used to predict the crystal phases composition of the sprayed coating.