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首次在TEM下直接观察和研究了钛(TA2)/钢(A3)界面结合层内的微观组织结构,从而在更微观的尺度上确立了界面结合层内的组织结构模型。揭示了爆炸复合界面通过局部熔化和扩散的物理冶金过程实现其“冶金结合”的机制。所建立的温度场模型可用以预测和分析界面结合层内的微观组织结构。 第一次利用TEM直接观察并研究了界面结合层内TA2例所产生的绝热剪切带(ASB)内的微观组织结构,结合ASB内的形变热力学条件首次利用动态再结晶理论和起塑变形理论阐明了ASB内细小(<0.1μm)等轴晶粒组织的产生机制及ASB内大剪切应变机制。首次基于材料热粘塑性本构失稳理论对材料本身的物理-力学-热学性能及其晶体结构相耦合进行综合分析,阐明了界面结合层内仅在TA2侧产生、ASB而在A3侧从未产生ASB的机制。 通过对界面微观断裂过程的动态观察和分析,揭示了其不同波形状态界面的微观断裂机制。 深入系统地研究了界面扩散反应区内的微观组织结构和反应相的形成、生长规律。所得结论可指导TA2/A3复合材的工业生产和应用。 本研究中有关金属在冲击载荷下的塑性变形机制和力学行为(孪生、绝热剪切等)的研究结果对研究金属在高应变率冲击载荷下的力学冶金行为具有指导意义。
For the first time, the microstructure of the titanium (TA2) / steel (A3) interfacial bonding layer was directly observed and studied under the TEM, and the microstructure model of interfacial bonding layer was established on a more microscopic scale. The mechanism of “metallurgical bonding” by the physical metallurgy process of partial fusion and diffusion of the explosive interface was revealed. The established temperature field model can be used to predict and analyze the microstructure in the interface bonding layer. For the first time, the microstructures in the adiabatic shear band (ASB) produced by TA2 in the interface-binding layer were observed and studied directly by TEM. The dynamic recrystallization theory and plastic deformation theory The mechanism of fine (<0.1μm) equiaxed grains in ASB and the mechanism of large shear strain in ASB were clarified. Based on the thermo-viscoplastic constitutive instability theory, the physical-mechanical-thermal properties and the crystal structure coupling of the material itself are analyzed for the first time. The results show that the interface bonding layer is only produced on the TA2 side, ASB on the A3 side The mechanism that produces ASB. Through the dynamic observation and analysis of the microscopic fracture process at the interface, the microscopic fracture mechanism at different wave-shaped interfaces is revealed. In-depth and systematic study of the interfacial diffusion reaction zone microstructure and reaction phase formation, growth law. The conclusions can guide the industrial production and application of TA2 / A3 composite. The results of researches on the plastic deformation mechanism and mechanical behavior (twin, adiabatic shear, etc.) of metal under impact load in this study are instructive for studying the mechanical metallurgical behavior of metal under high strain rate impact loading.