Double gradient porous HA/Mg composites where both porosity and HA exhibited gradient distribution were prepared by powder metallurgy method.Effects of the content and distribution of the pore former and HA on the porosity and compressive strength of the composites were analyzed.The microstructure of the sintered composites was observed

and corrosion resistance of the composites was examined.The results show that with the increase of the pore former in the inner layer of double gradient porous Mg/HA materials

the porosity of the composites is increased and compressive strength is decreased.With the increase of the HA content in the outer layer of double gradient porous HA/Mg composites

the compressive strength of the composites is decreased and the porosity of the composites is increased.The corrosion resistance measurement shows that with the increase of the porosity

the corrosion resistance of the composites is weaken.Double gradient porous HA/Mg composites is superior to gradient porous Mg material in corrosion resistance.With the increase of HA content in the outer layer of the composites

the corrosion rate of the composites is decreased and pH of solution is increased slowly.