The Preparation And Characteristics Of The Composite Materials Of Mg Alloy And Porous HA, HA/β-TCP

In this paper, we used Ca(NO3)2·4H2O and (NH4)2HPO4 as the reactants of wet synthesis, HA and HA/β-TCP slurry synthesized by controlling the initial Ca/P and the reaction process of pH, and added a certain amount of dispersant and binder, prepared different pore sizes of porous HA and HA/β-TCP used polymeric sponge impregnation process. In the last, prepared the composite materials HA/Mg-1Ca, (HA/β-TCP)/Mg-1Ca and (HA/β-TCP)/Mg-3Zn-1Mn by suction pouring Mg alloy in different pore sizes of porous HA and HA/β-TCP. By using SEM, XRD, optical microscope, precise image instrument, universal testing machine and electrochemical workstation analysis and tensile test, tested the porosity, pore size and compressive property of the porous HA and HA/β-TCP, and also studied the influence of pore size of porous HA and HA/β-TCP composite on materials microstructure, compressive property and corrosion resistance.The research of the porous HA, HA/β-TCP showed that porous material which used impregnation method was sintered by 50PPI and 60PPI polyurethane foam, the average pore size which were 0.8 mm and 0.4 mm respectively, the pore belonged to penetrability structure, the porosity was about 90%, the maximum compressive strength of the porous HA/β-TCP which pore size was 0.4mm reached 0.5MPa.Studied on the composite materials of HA/Mg-1Ca and (HA/β-TCP)/Mg-1Ca showed, the compressive strength of the composite material which prepared by the 0.4mm pore size porous material was better than which prepared by the 0.8mm pore size porous material, moreover the plasticity of (HA/β-TCP)/Mg-1Ca was better than HA/Mg-1Ca. During the two composite materials which immersed into the Hank's simulated body fluid, the pH changing trend of the body fluid was first fast raised then raised slowly, and basically stable at last, the (HA/β-TCP)/Mg-1Ca which prepared by the 0.8mm pore size HA/β-TCP changed most slowly, and its mass loss rate was most slowly, further illustrated its corrosion resistance was best.Studied on the composite material of (HA/β-TCP)/Mg-3Zn-1Mn showed, the compressive strength of the composite material which prepared by the 0.4mm pore size porous HA/β-TCP was better than which prepared by the 0.8mm pore size porous HA/β-TCP. but the compressive strength of the composite material (HA/β-TCP)/Mg-3Zn-1Mn which prepared by the 0.8mm pore size porous HA/β-TCP also reached 180MPa, it can meet the requirement of human bone's compressive strength. The electrochemical polarization curves and the simulated body fluid immersion test showed, the pH changing trend of (HA/β-TCP)/Mg-3Zn-1Mn which prepared by the 0.8mm pore size porous HA/β-TCP raised most slowly, the mass loss rate was also most slowly, illustrated its corrosion resistance was best, so it suited for biomedical material.