Interfacial reaction process of the hot-pressed WC/2024Al composite

12 vol%WCp/2024Al composite was fabricated from mixed powders by hot-pressing at various tempera-tures. Investigation of the interfacial reaction between the WC phase and the Al alloy matrix was performed by X-ray diffraction （XRD）, transmission electron microscope （TEM） and energy dispersive spectroscopy （EDS）. A multiple layer interface structure, which is composed of Al/ WAl12/AlnC3/WC, is found to form by the interfacial reaction during hot-pressing. Further study shows that the AlaC3 layer forms along with a given crystal orientation of WC phase and might retard the interfacial reaction process.

Formation of interfacial Al-Ce-Cu-W amorphous layers in aluminum matrix composite through thermally driven solid-state amorphization

Interfacial Al-Ce-Cu-W amorphous layers formed through thermally driven solid-state amorphization within the(W+Ce O2)/2024 Al composite were investigated.The elemental distributions and interfacial microstructures were examined with an electron probe microanalyzer and a high-resolution transmission electron microscope,respectively.The consolidation of composites consisted of two thermal processes:vacuum degassing(VD)and hot isostatic pressing(HIP).During consolidation,not only the three major elements(Al,W,and Ce)but also the alloying elements(Mg and Cu)in the Al matrix contributed to amorphization.At VD and HIP temperatures of 723 K and763 K,interfacial amorphous layers were formed within the composite.Three diffusion processes were necessary for interfacial amorphization:(a)long-range diffusion of Mg from the Al matrix to the interfaces during VD;(b)long-range diffusion of Cu from the Al matrix to the interfaces during HIP;(c)short-range diffusion of W toward the Al matrix during HIP.The newly formed interfacial Al-Ce-Cu-W amorphous layers can be categorized under the Al-Ce-TM(TM:transition metals)amorphous system.