Papers by Keyword: CuAl₂

Abstract: Water vapor in the air affects aluminum based intermetallic compounds to form hydrogen. We take advantage of this fact to explore the amount of hydrogen obtained from CuAl₂ intermetallic after its mechanical attrition activation. For this propose, CuAl₂ intermetallic alloy was first produced by conventional casting methods and then subjected to mechanical milling processing. After the mechanical activation of the CuAl₂ powders, a chemical reaction between them and water was carried out at room temperature including additives such as CaO, Al and NaCl. The amount of hydrogen release was correlated with other phases produced after the chemical reaction. X-ray diffraction patterns and scanning electron microscopy studies indicates that these phases were aluminum hydroxides and cupper oxides. According to these studies, a significant presence of oxide and hydroxide products occurred in the samples with NaCl additions, indicating best capability for hydrogen generation.

Abstract: Five-layered Al/Al-Cu functionally graded material (FGM) was fabricated by powder metallurgy technology. The microstructure and composition of the prepared specimen were studied. Vickers hardness, flexural strength and fracture surface morphology were also measured. The results showed that Al/Al-Cu graded material with dense structure and compositional continuous change was obtained by solution-precipitation method. The graded materials presented a compositional continuous change along the graded direction because of the diffusion effect, and the Vickers hardness was liner proportional to the distribution of Cu content. Compared with pure sintered Al, remarkable improvement on hardness and fracture strength was achieved due to the CuAl2 phase dispersively distributed in the matrix. With the increase of Cu content, the fracture mode changed from tough fracture to the tendency of brittle fracture.