等离子活化烧结法制备Ni基金属/金属间化合物叠层复合材料微观组织与拉伸行为（英文）

Microstructure and Tensile Behavior of Ni-Base Metal-Intermetallic Laminate Composites Prepared by Plasma Activated Sintering

采用等离子活化烧结法,通过Ni箔和Al箔的原位燃烧反应制备了镍基金属/金属间化合物叠层复合材料。微观结构观察表明叠层由反应层和剩余镍层交替组成,且反应层由多个金属间化合物单层构成。这些金属间化合物相的成分呈梯度分布,且随试样处理温度的升高,逐步由富铝相向富镍相转变。相应地,叠层复合材料的抗拉伸强度随着温度升高而逐渐升高,在1473 K温度下制备的复合材料具有最高的抗拉伸强度和伸长率。拉伸试样的断口形貌显示,在较低处理温度(1073和1173 K)制备的叠层复合材料,其断裂是由于金属间化合物层内的横向裂纹与镍层内的剪切带交互作用所引起的。随着处理温度升高,试样的断裂由多重裂纹模式向单裂纹模式转变。

Ni-base metal-intermetallic laminate （MIL） composites were obtained from in-situ combustion reaction between the Ni and Al foils by a plasma activated sintering （PAS）. Microstructural observation reveals that the laminates consist of alternate residual Ni layers and reacted layers which can be further divided into multiple layers of Ni-aluminides. The compositional gradient series of these intermetallic phases change in a stepwise fashion from Al-rich phases to Ni-rich phases with the increasing of the treatment temperature. Accordingly, the tensile strength of the composite increases steadily with the increase of temperature. The composites fabricated at 1473 K have the highest tensile strength and elongation. The fractographies of the tensile samples indicate that the failure of the composites treated at lower temperatures （1073 K and 1173 K） result from the interaction between the transversal cracks in the intermetallic layers and the shear bands in the Ni layers. When the treatment temperature increases, a transition from multiple cracking to a single cracking of the intermetallic layers can be observed.