To understand the synergistic effect of TiAl₃ and TiB₂ particles on grain refinement of α-Al, equal-channel angular pressing (ECAP) of Al-5Ti-1B (wt%) alloy was carried out. The ECAPed Al-5Ti-1B (wt%) alloy was characterized by X-ray Diffraction (XRD), electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The results reveal that α-Al grains and TiAl₃ phase of ECAPed Al-5Ti-1B (wt%) alloy were refined, while the average size of TiB₂was marginally decreased. The tensile strength was increased from 128 MPa to 218 MPa, and the elongation was reduced from 26% to 20.6%. The transformation from dislocations to low-angle grain boundaries (LAGBs) and high-angle grain boundaries (HAGBs) resulted in continuous dynamic recrystallization (CDRX), which induced grain refinement during ECAP. From 3 to 6 passes of ECAP, CDRX occurred in the alloy, and as ECAP passes increased to 9, the rate of formation of LAGBs and the transformation rate from LAGBs to HAGBs reached a dynamic balance. The present study indicates that the second phase particles promote the formation of LAGBs but prolong complete-recrystallization time, such that complete-recrystallization leads to grain refinement. TiB₂ particles are smaller than TiAl₃ particles and this is caused by the composition of the alloy and its synthesis method, and compared with TiAl₃, TiB₂ with a smaller size had a more obvious influence on the formation of LAGBs and grain refinement.

为了理解TiAl ₃和TiB ₂颗粒对α-Al晶粒细化的协同作用，进行了Al-5Ti-1B（wt％）合金的等通道角挤压（ECAP）。ECAPed Al-5Ti-1B（wt％）合金的特征在于X射线衍射（XRD），电子背散射衍射（EBSD）和透射电子显微镜（TEM）。结果表明，ECAPed Al-5Ti-1B（wt％）合金的α-Al晶粒和TiAl ₃相细化，而TiB ₂的平均尺寸略有下降。拉伸强度从128 MPa增加到218 MPa，伸长率从26％降低到20.6％。从位错到低角度晶界（LAGB）和高角度晶界（HAGB）的转变导致了连续动态重结晶（CDRX），从而在ECAP期间引起晶粒细化。从ECAP通过3到6次，合金中出现CDRX，随着ECAP通过至9次，LAGBs的形成速率和从LAGBs到HAGBs的转变速率达到了动态平衡。本研究表明，第二相颗粒促进了LAGBs的形成，但延长了完全重结晶时间，从而使完全重结晶导致晶粒细化。TiB ₂颗粒小于TiAl ₃这是由合金组成和合成方法引起的，与TiAl ₃相比，尺寸较小的TiB ₂对LAGBs的形成和晶粒细化的影响更为明显。