Electron Microscopy Characterization of Humidity Ball-Milling AlCuFe Intermetallic Powders
- PDF / 1,398,493 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 71 Downloads / 242 Views
Electron Microscopy Characterization of Humidity Ball-Milling AlCuFe Intermetallic Powders C. Patiño-Carachure1, O. Téllez-Vazquez1, A. Bedolla-Jacuinde1, R. Esparza2, C. ÁngelesChávez3, R. Perez2 and G. Rosas1 1
Instituto de Investigaciones Metalúrgicas, UMSNH, Edificio U, Ciudad Universitaria, CP 58060, Morelia Michoacán, MEXICO. 2 Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, P.O. Box 48-3, Cuernavaca, Mor., 62251, MEXICO. 3 Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas No 152, Col. San Bartolo Atepehuacan, D. F., 07730, MEXICO. ABSTRACT An Al 58 Cu 25 Fe 17 alloy composition was produced by conventional casting technique. In order to take advantage from the hydrogen-environmental embrittlement reaction, which affects these alloys, this research was carried out subjecting prealloyed powders to wet-ball milling. Through these experiments it has been possible to evaluate the particle size reduction as consequence of hydrogen fracture and milling energy. The morphological and structural characteristics of the samples were performed using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The experimental results indicate that the samples with higher contents of humidity have a good particle size reduction. With the increment of milling time, the particle size was diminished even more reaching nanometer size scale. INTRODUCTION The AlFe intermetallic compound are closely related to the Al 5 (Cu,Fe) 5 intermetallic phase[1,2]. Both phases share similar crystalline structure. However, in Al5(Cu,Fe) 5 alloy the copper is now part of atomic lattice that has given rise to a substitutional solid solution. AlFe intermetallic has important properties for its applications as structural materials at high temperatures [3-5]. However, the main drawback of these materials is its brittle nature at room temperature and its strong vulnerability to the hydrogen environmental embrittlement (HEE) [6]. The HEE mechanism in intermetallic compounds has been studied in the past [7,8]. The mechanism indicates that the water vapor in the air react with the aluminum of the alloy to produce alumina and hydrogen. Hydrogen diffuses inside of the intermetallic alloy and induces bond instability and causes cleavage fracture of the material. Recently, has been demonstrated that the ball milling under humidity conditions can be used to produce nanoparticles [9]. These experiments were carried out using high aluminum at% alloys. Therefore, in this work we used the high-energy ball milling to increase the rate of HEE reaction and evaluate the particle size reduction of Al 5 (Cu,Fe) 5 β-phase.
EXPERIMENTAL DETAILS Ingots of Al-Cu-Fe were prepared by conventional casting using an induction furnace and high purity elements (99.9%). The nominal composition of the alloy was Al 58 Cu 25 Fe 17 . Highenergy ball milling in air of prealloyed ingots were subsequently carried out using SPEX 8000 mixer/mill equipment. The samples
Data Loading...
