摘要
In this study,Mg-9 Al-1 Si-1 SiC(wt%)composites were processed by multi-pass equal-channel angular pressing(ECAP)at various temperatures,and their microstructure evolution and strengthening mechanism were explored.Results showed that the as-cast microstructure was composed of anα-Mg matrix,discontinuous Mg17Al12 phase,and Chinese script-shaped Mg2Si phase.After solution treatment,almost all of the Mg17Al12 phases were dissolved into the matrix,whereas the Mg2Si phases were not.The subsequent multi-pass ECAP at different temperatures promoted the dynamic recrystallization and uniform distribution of the Mg17Al12 precipitates when compared with the multipass ECAP at a constant temperature.A large number of precipitates can effectively improve the nucleation ratio of recrystallization through a particle-stimulated nucleation mechanism.In addition,the SiC nanoparticles were mainly distributed at grain boundaries,which effectively prevented dislocation movement.The excellent comprehensive mechanical properties can be attributed to grain boundary strengthening and Orowan strengthening.
基金
supported by the National Natural Science Foundation of China(Nos.51404166,51704209,and U1810208)
Shanxi province scientific facilities and instruments shared service platform of magnesium-based materials electric impulse aided forming(No.201805D141005)
Science and Technology Major Project of Shanxi province(Nos.20191102008,20191102007,20191102004,and 20181101008)
Natural Science Foundation of Shanxi Province(No.201701D121045)
Shanxi Province Science Foundation for Youths(No.2016021063)
The Projects of International Cooperation in Shanxi(No.201803D 421086)
。
