準結晶を含むＡｌ‐７．８％Ｖ‐４％Ｆｅ合金Ｐ／Ｍ材の組織と耐摩耗性

Abstract

Microstructure and wear properties of an Al–7.8 mass%V–4 mass%Fe P/M alloy were examined with a transmission electron microscope (TEM) and a wear testing machine. It is confirmed by TEM that icosaphedral quasicrystalline (Q.C.) particles with a size of about 400 nm precipitate in the alloy. The analysis by an energy dispersive x–ray spectrometer indicates that the composition of Q.C. particles is Al–20.3 mass%V–6.7 mass%Fe. The rapidly quenched ribbon with the same composition that of Q.C. particles consists of a nearly single phase of Q.C.. The structure and morphology of Q.C. particles remain unchanged after heat treatment for 200 h at 573 K, indicating that the Q.C. phase is stable even at high temperatures. The wear measurement was made for the Al–7.8 mass%V–4 mass%Fe alloy and commercial aluminum alloy A390–T6. For both alloys the specific wear rate at slid ing velocities from 0.5 to 1.3 m/s is almost constant, i.e., 2.6 × 10−7 mm2/kg for Al–7.8 mass%V–4 mass%Fe alloy and 2.5 × 10−7 mm2/kg for A390–T6 aluminum alloy. The specific wear rate of Al–7.8 mass%V–4 mass%Fe alloy remains independent of the sliding velocity up to 2.0 m/s, while that of the A390–T6 aluminum alloy increases rapidly at sliding velocities above 1.3 m/s. These results indicate that the Al–7.8 mass%V–4 mass%Fe alloy with high elevated–temperature strength has also high wear resistance.