Three-dimensional orthogonal C

f

/Al composites with volume fraction of 50% C

f

were fabricated by vacuum pressure infiltration.The microstructure and bending properties of the composites at room temperature and high temperature were investigated.The failure mechanism of bending properties of the composites was described.The results indicate that the micro-void defects in the warp microstructure of three dimensional orthogonal C

f

/Al composites are slightly more than those in the weft microstructure.The bending strength of the composites at room temperature、350℃and 400 ℃ reaches 498.8 MPa、363.0 MPa and 303.0 MPa

respectively.The bending modulus of the composites at room temperature、350℃ and 400℃ reaches 70.8 GPa、63.7 GPa and 65.6 GPa

respectively.The bending failure is mainly attributed to the buckling deformation of the warp fiber bundles caused by the compression on the inner surface

and the morphology of weft fiber bundles is relatively intact.In addition

the tensile failure of the composites is caused by the tension of the external side and existence of fiber pull-out.