Microstructural characterization of dispersion-strengthened Cu–Ti–Al alloys obtained by reaction milling

Creep behavior of a dispersion-strengthened Cu–Ti–Al alloy obtained by reaction milling

“…The resulting aggregates were encapsulated at low vacuum and then consolidated by hot extrusion at 1023 K, using an extrusion ratio of 10:1. Other processing details are described elsewhere [9]. Cylindrical specimens 6.5 mm in diameter and 9.8 mm in length were machined from as-extruded bars, with the axis parallel to the extrusion direction.…”

“…The characterization and microstructural description of the H-20 alloy used in the present creep tests has been reported elsewhere [9]. Briefly, the material exhibited a stable microstructure with nanodispersoids homogeneously distributed both at the grain boundaries and within the grains.…”

“…On the other hand, under the assumption that all the Al and Ti detected in the alloy chemical analysis [9] reacts forming Al 2 O 3 and TiC particles, a total volume fraction for these two dispersed phases f 0 = 0.049 is obtained. The difference between this value and f m is here associated to the precipitation of dispersoids in grain boundaries.…”

“…In a preceding paper [9], we described the processing and microstructural characterization of two dispersion-strengthened alloys of nominal-composition Cu-2.5 vol%TiC-2.5 vol% Al 2 O 3 , obtained by reaction milling and followed by extrusion. It was shown that one of the developed alloys, referred to as the H-20 alloy, presented a stable microstructure with Ti-Al-Fe nanodispersoids embedded in the Cu matrix.…”

“…Creep tests were performed at 773, 973 and 1123 K, under loads that produced steady-state creep rates between ∼9 × 10 −7 and ∼2 × 10 −4 s −1 . These experimental results, taking into account the previously reported TEM microstructural characterization [9], are then analyzed within the framework of existing creep models [7,8], and the operating creep mechanisms are determined.…”