Preparation And Properties Of Three-dimensional Interpenetrating Minimal Surface Ceramic/aluminum Alloy Composites

Interpenetrating Phase Composites（Interpenetrating Phase Composites）is a new direction to study multi-functional composites with excellent mechanical properties.At present,the main problem of preparing composite materials by using aluminum alloy solution impregnated ceramic skeleton is that the surface of the ceramic skeleton prepared by traditional molding methods is rough,which is difficult to meet the design requirements of the skeleton structure.At the same time,the current research on composite structures is mostly based on honeycomb structure,which is simple in structure and poor in performance.In this paper,a minimum-curved three-dimensional network ceramic/aluminum alloy composite material was designed,and the three-dimensional minimum-curved ceramic skeleton structure was printed by light curing 3D printing technology.The aluminum alloy solution was impregnated into the prepared ceramic skeleton,and the three-dimensional interpenetrating ceramic/aluminum alloy composite material with fine structure and high interface bonding strength was successfully prepared.The effects of Al₂O₃ ceramic slurry preparation process,3D printing process and non-pressure infiltration process on the microstructure properties of composite materials were analyzed.The research results are as follows:（1）The influence of different layer thickness and laser power on the printed product was studied,and the best printing process parameters of the ceramic skeleton were obtained.When the laser frequency is 10000 Hz,the printing thickness is 0.05 cm,and the laser power is about 40%,the forming effect of the ceramic skeleton is the best,the structure is complete,the surface is smooth,there is no obvious crack,and it has excellent mechanical properties.（2）The effects of different heating rate,degreasing temperature and holding time on the degreasing sintering of green billet were studied.The optimum degreasing process was as follows:heating rate 0.4℃/min,temperature 650℃,time 2.5 h;The best sintering process is:temperature rise of 5℃per minute,heat preservation of 2.5 h,in order to ensure the integrity of the skeleton structure can shorten the sintering time.（3）The influence of different aluminum alloy composition,infiltration temperature and heating conditions on the infiltration experiment was studied,and the optimal infiltration process was obtained as follows:Mg Al₂O₄ and Mg O were generated by using a five-series metal with high magnesium content at the infiltration temperature of 950℃in a circulating nitrogen atmosphere,so as to enhance the interface bonding between aluminum alloy and ceramic particles.（4）The compressive fracture behavior of Al₂O₃/Al composites with minimal curved surface and honeycomb structure was studied,and the main fracture mechanism was analyzed.The results showed that the ultimate compressive strength and energy absorption of Al₂O₃/Al composites with TPMS structure were 260.64 MPa and 791.19KJ/m³,respectively.It is 4.8 times and 15.5 times that of honeycomb structure,respectively.It is found that TPMS structural composites can decompose stress and transfer load well due to its smooth and regular topological structure,and have higher strength and ductility than honeycomb structures.The SEM results show that the compressive failure of the composites is a mixed fracture composed of ductile and brittle fracture.