Study on Critical Infiltration Behavior and Law of Liquid Aluminum Alloy in Carbon Fiber Preform

Infiltration effect is an important factor for the preparation of ideal CF/Al composites by liquid infiltration method, so it is necessary to study the infiltration law of aluminum alloy in carbon fiber preform to obtain composite with sufficient and uniform infiltration effect. Through theoretical analysis and calculation of statics and dynamics, critical infiltration pressures of the liquid aluminum alloy in the 2D carbon fiber preform were 0.53 MPa and 3.24 MPa, respectively, when carbon fiber volume fraction was 45 %. Mechanical pressure infiltration method was used to study critical infiltration pressures and behavior of the liquid aluminum alloy in the 2D carbon fiber preform, and the experimental results indicated that the infiltration front of aluminum alloy had never broken through the surface of carbon fiber preform, when the infiltration pressure was 3.5 MPa. Carbon fibers and aluminum alloy were separated and the infiltration effect was not ideal under the pressure of 3.5 MPa. When the infiltration pressure was 7 MPa, the infiltration could be implemented. The actual infiltration pressure of the experiments is greater than the theoretical calculation value, because viscous resistance, solidification resistance and other factors are ignored in the calculation process. However, infiltration depth increases with increase in infiltration time at infiltration pressure of 7 MPa, and this verifies the correctness of the previous theoretical research results.