Aluminium Matrix Composite Materials Reinforced by 3D-Printed Ceramic Preforms.

Current methods for creating ceramic-reinforced metal composites face challenges in achieving uniform microstructures and low porosity. Prior research has shown that traditional infiltration techniques often result in uneven reinforcement distribution and residual porosity. No prior work had resolved the issue of maintaining structural integrity during binder removal and sintering. This gap motivated the development of a new approach using 3D-printed ceramic preforms. The use of 3D printing allows for precise control over the geometry of the reinforcing phase. However, the integration of 3D-printed structures with metal matrix composites remains underexplored. The challenge lies in ensuring complete binder removal and avoiding carbon residue. This study addresses these limitations by combining 3D printing with gas-pressure infiltration.

The aim of this study was to develop a method for manufacturing alumina-reinforced AlSi12 composites using 3D-printed ceramic preforms. The specific problem addressed is the difficulty in achieving low porosity and uniform reinforcement distribution in metal matrix composites. The motivation stems from the need for stronger and more durable materials in industrial applications. The study sought to evaluate the feasibility of using fused deposition modelling for creating porous alumina skeletons. The researchers also aimed to optimize the sintering process to eliminate residual carbon. A secondary goal was to assess the mechanical properties of the resulting composites. The study focused on the interplay between printing parameters and final material performance. The ultimate objective was to establish a reproducible and scalable manufacturing process.

The researchers used fused deposition modelling to create alumina powder-filled filaments for 3D printing. Two different filament types were tested to compare their sintering behavior. After printing, the organic components were removed using a solvent and heat debinding process. The printed structures were then sintered at 1500 °C to form porous alumina skeletons. Thermogravimetric analysis and differential thermal analysis were used to determine optimal sintering conditions. The sintered samples were analyzed for porosity and microstructure. Gas-pressure infiltration was used to introduce liquid AlSi12 into the ceramic preforms. The final composites were evaluated using scanning electron microscopy, computer tomography, and mechanical testing.

The sintering process produced alumina samples with no detectable carbon residue. The open porosity in the ceramic skeletons was attributed to binder degradation. Liquid metal infiltration successfully filled the pores and formed a 3D network of the aluminum phase. The resulting composites exhibited low porosity and a uniform distribution of the reinforcing phase. Mechanical testing showed that the composites had higher hardness than the base AlSi12 matrix. The bending strength of the composites was also improved compared to the pure metal. Scanning electron microscopy confirmed the homogeneity of the microstructure. The developed method demonstrated the potential for practical application in composite manufacturing.

The study demonstrated that 3D-printed alumina preforms can be effectively used to create metal matrix composites. The sintering process successfully removed all organic components without leaving carbon residue. The infiltration of liquid metal resulted in a uniform distribution of the reinforcing phase. The mechanical properties of the composites exceeded those of the base material. The absence of residual porosity improved the overall structural integrity. The method offers a scalable and reproducible approach to composite manufacturing. The researchers propose that this technology can be applied in industrial settings. The findings suggest that the developed process is suitable for producing high-performance materials.