Hot deformation behavior and ring rolling process of SiCp/Al composites used in aircraft manufacturing

To study the thermal deformation behavior of high-strength and high-toughness SiC particle reinforced aluminum matrix composites (SiCp/Al) used in aircraft manufacturing and to provide the technical basis for the preparation of large size rings by ring rolling used for the aviation, the 17%SiCp/Al composites (volume fraction) were prepared by powder metallurgy process. The stress-strain relationships of the SiCp/Al composites under the different thermal deformation conditions were obtained through the thermal compression experiments at the different temperatures and deformation rates, and the thermal working diagram was established according to the relationship. In the results, with the increase of deformation, the SiCp/Al composites are prone to the instability deformation at the deformation temperature lower than 440 ℃ or higher than 490 ℃ and the deformation rates higher than 0.100 s^‒1. When the deformation temperature and deformation rate of the SiCp/Al composite are not suitable, besides the traditional process defects such as the instability deformation but also the surface cracking caused by the particle damage may occur, which cannot be removed by machining and should be avoided. Finally, under the guidance of the hot working diagram and the verification of the ring rolling experiment, the process parameters suitable for the ring rolling of the SiCp/Al composite are given, and the circular workpieces prepared using the SiCp/Al composites with the outer diameter of 1200 mm are prepared.