Study On The Preparation Technology And Performance Of 3D-reticulated Porous SiC/Fe Composite Material

3D-reticulated porous（3D-RP）SiC ceramic was fabricated by polymer sponge replica technique with SiC ceramic slurry（77.0 wt%solid content）then the 3D-RP SiC preform was treated with secondary slurry by vacuum infiltration.At the same time,the mechanical properties of the prefabricated body are improved by changing the composition of secondary slurry and optimizing the precast surface structure.On that basis,3D-RP SiC/Fe composite materials based on the reinforcing material of 3D-RP SiC ceramics and iron were fabricated by normal pressure casting.And the compressive strength and internal structure of the 3D-RP SiC preform as well as the interface bonding,internal structure,compressive strength and wear resistance of the composite materials were analyzed,then calculating the reasonable experimental method and the composition ratio of the preparation of 3D-RP SiC/Fe composite materials.Through the secondary slurry technology（under the condition of 0.095 Mpa）,the internal triangular hole and skeleton cracks in preforms are fully filled by alumina slurry（77.0 wt%solid content）,and the pressure of the 3D-RP SiC preform is increased from0.3 Mpa to 0.78 Mpa.In addition,a moderate amount of rare earth oxides（Y₂O₃ and CeO₂）are added to the alumina slurry,and the compressive strength of the 3D-RP SiC preforms is increased to 0.95 Mpa.Moreover,the surface treatment of the 3D-RP SiC preform is carried out by means of high temperature and high pressure,and its compressive strength reachs 0.83 Mpa.Due to the defect of the process,the triangular hole is not fully filled.The analysis result of 3D-RP SiC/Fe composite materials show that an excellent interface bonding between 3D-RP SiC ceramic and iron matrix formed and intermediate products and apparent defects are not measured in the interface.Particularly,the 3D-RP SiC preform with the Ni coating is more closely bound with the metal matrix.And the abrasive resistance of 3D-RP Si C/Fe composite materials is 2.1⁷.9 times that of gray cast iron HT300,and the abrasive resistance of composite materials increases with the improvement of the compressive strength of 3D-RP SiC ceramic.The wear mechanism of 3D-RP Si C/Fe composite material is predominantly oxidative wear and adhesive wear,together with partial abrasive wear if under a high load.In addition,by theoretical calculation,the compressive strength of the 3D-RP SiC/Fe composite materials is about344.29 Mpa,and the strength increases as the volume of the Si C ceramic increasing.