Effect of carbon fibers content in selective laser sintering sand mold on relative density and mechanical properties of vacuum counter-pressure casting ZL205 Aalloy were analyzed by testing the aluminum castings prepared by resin coated sand mold with five different carbon fibers contents.The results indicate that with increase of the carbon fibers content

relative density of the ZL205 Aalloy is increased

and tensile strength and elongation of the ZL205 Aalloy are increased firstly and then decreased.The relative density

tensile strength and elongation of the ZL205 Aalloy reach 0.9962

496.42 MPa and10.23%

respectively

with 3%carbide fibre content.When carbide fibre content is more than 3%

relative density of the alloy is decreased.