Accumulative press bonding (APB) is proposed as a novel method for inducing severe plastic deformation. This process can produce a homogeneous and ultrafine-grained nanocomposite, which is extremely difficult to obtain by other processes. AA1050/SiCp nanocomposite with an average grain size of 280 nm and well-developed high-angle grain boundaries (39� average misorientation angle and 82% high-angle boundaries) exhibited the highest tensile strength reported in the literature, i.e. 284 MPa. Theoretical models revealed that the contributions of Orowan and grain refinement strengthening mechanisms to yield strength were 76.6% and 14.8%, respectively.