Ultrasonic consolidation of pure Al and composite Al-Ni powder compacts

Abstract

A novel ultrasonic powder consolidation technique was employed to produce monolithic Al and composite Al-Ni compacts (0.5 mm thick, 3.5 mm in diameter) from elemental powders. Al specimens were prepared systematically at temperatures up to 300°C and pressures up to 120 MPa, while keeping the vibration frequency, duration, and amplitude fixed at 20 kHz, 1 s, and 10 urn, respectively. Examination by optical and scanning electron microscopy showed that full-density, oxide-free consolidation in air is possible. Full density-consolidated Al specimens withstood 180° bending at room temperature. Al-Ni specimens (1:1 molar ratio), fabricated under similar conditions, were also fully dense exhibiting a composite microstructure of Ni particles distributed uniformly in an Al matrix. Differences in microstructure and ductility are discussed with respect to processing conditions. © 2008 MS&T\u2708®