X-ray tomography studies on porosity and particle size distribution in cast in-situ Al-Cu-TiB₂ semi-solid forged composites

X-ray computed tomography (XCT) was used to characterise the internal microstructure and clustering behaviour of TiB₂ particles in in-situ processed Al-Cu metal matrix composites prepared by casting method. Forging was used in semi-solid state to reduce the porosity and to uniformly disperse TiB₂ particles in the composite. Quantification of porosity and clustering of TiB₂ particles was evaluated for different forging reductions (30% and 50% reductions) and compared with an as-cast sample using XCT. Results show that the porosity content was decreased by about 40% due to semi-solid forging as compared to the as-cast condition. Further, XCT results show that the 30% forging reduction resulted in greater uniformity in distribution of TiB₂ particles within the composite compared to as-cast and the 50% forge reduction in semi-solid state. These results show that the application of forging in semi-solid state enhances particle distribution and reduces porosity formation in cast in-situ Al-Cu-TiB₂ metal matrix composites. - Highlights: •XCT was used to visualise 3D internal structure of Al-Cu-TiB₂ MMCs. •Al-Cu-TiB₂ MMC was prepared by casting using flux assisted synthesis method. •TiB₂ particles and porosity size distribution were evaluated. •Results show that forging in semi-solid condition decreases the porosity content and improve the particle dispersion in MMCs.