Fabrication of Intermetallic Fiber/Metal Matrix Graded and/or Smart Composites by a Reaction at Narrow Holes Method

窄孔反应法（RANH法）是一种制备金属间化合物纤维/金属基复合材料的方法。在金属基体A中钻出具有小直径的窄孔。金属纤维B插入这些窄孔中。在升高的温度下加热包括金属基体A和金属纤维B的组件，以在窄孔中获得熔融金属B。那么，mA+nB→AmBn的反应至少应该发生在窄孔中。在处理之后，将组件冷却至环境温度。本研究采用RANH法制备了镍-铝系纤维/镍复合材料和铜-铝系复合材料。镍铝纤维/镍基复合材料1）反应区域仅限于纤维状区域，结果表明：（1）1000 ℃热处理后的试样硬度较高，1000 ℃和1200 ℃热处理后的试样中存在大量的气孔;（2）1000 ℃热处理后的试样硬度较高，1200 ℃热处理后的试样中存在大量的气孔在低于700 ℃的温度下加热，在孔周围形成双环区。内部环形区域由单相的γ1金属间化合物组成，具有非常高的硬度。外环形区由具有中等硬度的Al-Cu固溶体组成。2）当环形区域沿孔的边缘沿着形成为具有恒定宽度时，所得样品具有保持其原始窄孔的圆形截面形状的孔。

The reaction at narrow holes method (RANH method) has been proposed as a method for fabricating an intermetallic compound fiber/metal matrix composite. Narrow holes having a small diameter are drilled in a metal matrix A. Metal fibers B are inserted into these narrow holes. The assembly comprising the metal matrix A and metal fibers B is heated at elevated temperatures to obtain molten metal B in the narrow holes. Then, the reaction of mA+nB→AmBn should occur at least in the narrow holes. After the processing, the assembly is cooled to ambient temperature. Consequently, the intermetallic compound AmBn fiber/metal matrix A composite can be fabricated.In this study, a nickel-aluminides fiber/nickel composite and a copper-aluminum system composite are fabricated by the novel method, RANH method. The results are summarized as follows.Nickel-aluminides fiber/nickel composite1)Reacted region is limited to the fiber shaped region, since the nickel-aluminide replaces the pure aluminum maintaining its fiber shape surrounded by the nickel matrix.2)High hardness could be achieved for specimens beat-treated at 1000 ℃.3)Specimens heat-treated at 1000 ℃ and 1200 ℃ have lots of pores.Copper-aluminum system composite1)Double annular regions are formed around the hole by heating at a temperature less than about 700 ℃. The inner annular region consists of γ1 intermetallic compound in a single phase having very high hardness. The outer annular region consists of Al-Cu solid-solution having a mid-level hardness. The annular regions may work as a reinforcing metal fiber in FRM.2)When the annular region is formed with a constant width along the edge of the hole, the resultant specimen has the hole maintaining its circular section shape of the original narrow hole.