Deformation Behavior And Properties Of Al/Al-Al₂O₃/Al Laminated Aluminum Matrix Composites

Particle Reinforced Aluminum Matrix Composites（PRAMCs）have a broad application prospect in military,aerospace,rail transportation and electronic communication fields due to their low density,high specific strength and wear resistance.However,PRAMCs are prepared with uneven particle distribution and weak particle/matrix interfacial bonding and prone to cracking,resulting in a significant decrease in plasticity and fracture toughness,which severely limits the application scenarios of aluminum matrix composites as structural components.Therefore,the mismatch between strength and plasticity/toughness of PRAMCs needs to be solved urgently.In this paper,we designed pure aluminum materials and aluminum matrix composites with"hamburger"structure by taking advantage of the laminate structure,and successfully prepared 1060Al/CS-Al/1060Al laminate pure aluminum materials and1060Al/Al-Al₂O₃/1060Al laminate aluminum matrix composites by combining heat treatment and rolling process.aluminum matrix composites.The heat deformation behavior was studied,and the microstructure and mechanical property changes at each stage of preparation were analyzed to establish the correlation of"process-tissue-property"and provide theoretical support for the preparation of high performance laminated aluminum matrix composites.The main findings are as follows:The flattening rate of Al particles in CS-Al pure aluminum material and Al-Al₂O₃aluminum matrix composites prepared by CSAM technology is 58%and 37.5%,respectively,and Al₂O₃ particles promote the interfacial bonding of Al matrix.The grain size of Al-Al₂O₃ Al matrix composites increased after heat treatment,the recrystallization and deformation crystal content decreased,the subgrain content increased,and the dislocation density distributed at the particle boundaries decreased significantly.The porosity of CS-Al pure aluminum material and Al-Al₂O₃ aluminum matrix composites decreased from 5.23%and 3.08%to 2.71%and 1.62%,respectively,with increasing heat treatment temperature and time.the tensile strength of CS-Al pure aluminum material was 59.2 MPa and elongation was 7.73%at 450℃/2 h,which increased by 4%and 286%,respectively,compared with the cold sprayed state;Al-Al₂O₃ aluminum matrix composites showed strength and elongation of 73.8 MPa and 7.2%after 450°C/2 h,which were 5.7 MPa lower in tensile strength but 260%higher in elongation compared with the cold sprayed state.The fractures showed typical brittle fracture characteristics before heat treatment,and ductile fracture characteristics started to appear after heat treatment.Both 1060Al/CS-Al/1060Al laminated pure aluminum material and 1060Al/Al-Al₂O₃/1060Al laminated aluminum matrix composite deformation process is dominated by work hardening,but the rheological stress increases significantly with the addition of reinforcing particles;moreover,the rheological stress increases with increasing strain and deformation rate and decreases with increasing temperature.The more suitable rheological stress prediction models for 1060Al/CS-Al/1060Al laminated pure aluminum materials and 1060Al/Al-Al₂O₃/1060Al laminated aluminum matrix composites are MJC model and MZA model,respectively.The correlation coefficients（R）and average relative errors（AARE）of the two models were 0.98364,0.065332 and 0.99085,0.046966,respectively.The suitable thermal processing process parameters for the two laminated composites were 350-400°C,0.01-0.1 s^-1 and 275-350°C,0.01-1 s^-1,respectively.The grain orientation in the 1060Al/Al-Al₂O₃/1060Al laminated aluminum matrix composites was random,and the average grain size increased,the substructured grain content decreased significantly,the deformed grain content increased significantly,and the dislocation density became significantly larger at higher temperatures and strain rates compared to low temperatures and low strain rates.No obvious cracks appeared in the intermediate layers of both laminated composites at different rolling temperatures,and the macroscopic interfaces of the laminated pure aluminum materials were relatively flatter compared with those of the laminated aluminum matrix composites with Al₂O₃ particles added.The flattening of Al particles after rolling was about 10%,with fewer defects and reduced and blurred interfacial spacing of the particles.The grain sizes were 1.81μm,1.75μm and 1.82μm at the three rolling temperatures,respectively,and the subcrystalline content decreased sharply,the deformed crystal content increased sharply and the dislocation density increased after rolling compared with the heat treatment state.The tensile strength of 1060Al/CS-Al/1060Al laminated pure aluminum material gradually decreased and the elongation gradually increased with the increase of rolling temperature,and the highest tensile strength was 125.1 MPa at 260℃and the highest elongation was 8.8%at 400℃;with the increase of rolling temperature,the 1060Al/Al-Al₂O₃/1060Al laminated aluminum matrix composites The tensile strength gradually decreased and the elongation was the first to decrease and then increase,with the highest tensile strength of 119.3 MPa at 260℃and the highest elongation of 12.4%at 400℃.With the increase of rolling temperature,the number of tough nests in the cold sprayed additive layers of both laminated composites increased and were more uniformly distributed.