中温轧制制备镁/铝/钽多层复合材料的界面扩散与力学性能研究

Interface Diffusion and Mechanical Properties of Mg/Al/Ta Multilayer Composites Prepared by Medium Temperature Rolling

目的实现镁铝钽异种金属复合板材的制备并优化复合板材的力学性能,以获得强轻质-高抗辐射屏蔽性能的复合金属材料。方法通过中温轧制工艺,先进行首道次大压下量轧制、随后不断提升轧制道次的方法开展Mg-Al-Ta板材轧制复合研究,分析不同轧制道次下Mg-Al-Ta的界面扩散行为。结果通过引入Al过渡层,成功实现Mg-Al-Ta轧制复合,不同轧制道次下制备出的Mg-Al-Ta层状复合材料表面较为平整,界面处结合良好;Mg-Al和Al-Ta界面的扩散宽度均随着轧制道次的增加而增大,在1道次到5道次的轧制中,Al-Ta界面的扩散宽度由1.2μm增大到5.18μm,Mg-Al界面的扩散宽度由2.38μm增大到4.25μm,随着轧制道次的增加,界面层硬度逐渐增大;Mg-Al-Ta层状复合板材的抗拉强度随轧制道次的增加而增大,2道次和5道次轧制板材的抗拉强度分别达到293、365 MPa;轧制道次对板材的塑性影响较小,不同轧制道次的复合板材伸长率均不足1%。结论研究结果表明,Al是互不相溶金属Mg和Ta冶金结合的有效媒介;中温轧制的热力耦合作用是实现Mg-Al-Ta板材协同变形和界面扩散的主要机制。

The work aims to realize the preparation of Mg-Al-Ta dissimilar metal composite plates and optimize the mechanical properties of the composite plates,to obtain composite metal materials with strong light weight and high radiation shielding performance.A study on the rolling composite of Mg-Al-Ta plates was carried out by a medium temperature rolling process,starting with the first pass with a large depression,followed by continuous upgrading of the rolling passes,and the interface diffusion behavior of Mg-Al-Ta at different rolling passes was analyzed.The Mg-Al-Ta laminated composite was successfully rolled by introducing Al transition layer,and the surface of the Mg-Al-Ta laminated composite prepared under different rolling passes was relatively flat and well bonded at the interface;the diffusion width of both Mg-Al and Al-Ta interfaces increased with the increase of rolling passes,and the diffusion width of Al-Ta interface increased from 1.2μm to 5.18μm,and the diffusion width of Mg-Al-Ta interface increased from 2.38μm to 4.25μm with the increase of rolling passes from 1 to 5.With the increase of rolling pass,the hardness of interface layer increased gradually.The tensile strength of Mg-Al-Ta laminate increased with the increase of rolling passes,and the tensile strengths of Mg-Al-Ta laminate reached 293 MPa and 365 MPa for 2 and 5 passes,respectively.The rolling pass had little effect on the plasticity of the plate,and the elongation of the composite plate with different rolling passes was less than 1%.The results show that Al is an effective medium for the metallurgical bonding of the mutually insoluble metals Mg and Ta.The thermal coupling effect of medium temperature rolling is the main mechanism to achieve the synergistic deformation and interface diffusion of Mg-Al-Ta sheets.