Study On Preparation And Properties Of Al₆Fe Nanowires

Al-Fe alloy has a wide application prospect in aerospace and automobile fields for its advantages light weight and high heat-resistance.The content of aluminum and iron are abundant in the crust which not only reduces the cost of Al-Fe alloy,but also makes effective use of resources.The thick needle-like Al3Fe in Al-Fe alloys will split the matrix,while the Al₆Fe phase will not split the matrix because of its regular rod-like morphology.In order to determine the suitable preparation method of Al₆Fe nanowires and test their properties,the characteristics of solidification structure of DC casting Al-3Fe alloy were analyzed.Besides,I investigated the effects of different corrosives and corrosion conditions on the preparation of Al₆Fe nanowires and the mechanical properties of Al₆Fe nanowires.The conclusions are as follows:（1）The as-cast structure of DC casting Al-3Fe alloy consists of α-Al and Al₆Fe eutectic structure.A large number of fine and regular nanorod-like Al₆Fe phases are formed in the crystalline cells of the columnar crystal zone of the billet,with a diameter of 90 nm and a volume fraction of 10%.（2）The tensile strength of DC casting Al-3Fe alloy is 217.5 MPa,yield strength is 90.04 MPa and elongation is 10.84%at room temperature.Al-3Fe alloy shows ductile fracture because its fracture surface is composed of layered tearing and dimples.During the tensile process,Al₆Fe phase undergoes plastic deformation with the matrix,which enhances the plastic deformation ability of the alloy.（3）Al₆Fe nanowires with regular shape can be prepared by using ethanol as a suitable corrosive agent after 48 hours of corrosion under the catalysis of AlCl₃ and repeated cleaning with deionized water.Al₆Fe nano wires with a diameter of 80 nm and a length of more than ten to tens of microns were prepared and grown preferentially in the direction of [（?）00].（4）Al₆Fe nanowires exhibit strong brittleness in tensile tests.Point defects concentrated on the same crystal plane and zigzag surface morphologies become the "key defects" of Al₆Fe nanowires with high brittleness.