In the present work, solid-liquid compound casting process was used to fabricate TC4/AZ91D bimetals using thermal diffused Ni-coated TC4 alloy. The effects of thermal diffusion time of Ni-coated TC4 alloy on interface microstructure evolution and mechanical features of TC4/AZ91D bimetals were investigated. The interface microstructure has undergone the evolution of NiTi₂, NiTi and Ni₃Ti to NiTi₂, NiTi and Ni₂Ti₄O (Mg) at Ni–Ti interface and (Mg₂Ni + α-Mg) eutectic structure + Ni₂Mg₃Al ternary phase to eutectic-free (only Al₃Ni, Al₃Ti and Ni₂Mg₃Al) at Ni–Mg interface as the thermal diffusion time of Ni-coated TC4 alloy increased from 0.5 h to 5 h and 9 h. The maximum shear strength of 105.2 MPa was obtained for the eutectic-free interface of TC4/AZ91D bimetals when Ni-coated TC4 alloy were thermal diffused by 5 h. The rupture of TC4/AZ91D bimetals mainly takes place at (Mg₂Ni + α-Mg) eutectic structure or between the interface of Ni₃Ti layer/(Mg₂Ni + α-Mg) eutectic structure when the thermal diffusion time of Ni-coated TC4 alloy is 0.5 h. Besides, with the thermal diffusion time increases to 5 and 9 h, the rupture occurs at the NiTi₂ and Ni₂Ti₄O (Mg) reaction layers, respectively.

在目前的工作中，采用固液复合铸造工艺，使用热扩散镀镍 TC4 合金制造 TC4/AZ91D 双金属。研究了镀镍TC4合金的热扩散时间对TC4/AZ91D双金属界面组织演变和力学性能的影响。界面组织经历了NiTi ₂、NiTi 和Ni ₃ Ti 向NiTi ₂、NiTi 和Ni ₂ Ti ₄ O (Mg) 在Ni-Ti 界面和(Mg ₂ Ni + α-Mg) 共晶结构+ Ni ₂的演变Mg ₃ Al 三元相至无共晶（仅 Al ₃ Ni、Al ₃ Ti 和 Ni ₂ Mg₃ Al）在 Ni-Mg 界面处，随着 Ni 涂层 TC4 合金的热扩散时间从 0.5 小时增加到 5 小时和 9 小时。当镀镍 TC4 合金热扩散 5 h 时，TC4/AZ91D 双金属无共晶界面的最大剪切强度为 105.2 MPa。TC4/AZ91D双金属的破裂主要发生在(Mg ₂ Ni + α-Mg)共晶结构或Ni ₃ Ti层/(Mg ₂ Ni + α-Mg)共晶结构的界面之间涂层 TC4 合金为 0.5 小时。此外，随着热扩散时间增加到 5 h 和 9 h，破裂分别发生在 NiTi ₂和 Ni ₂ Ti ₄ O (Mg) 反应层。