Effect of mechanical alloying and sintering process on microstructure andmechanical properties of Al-Ni-Y-Co-La alloy
(1. Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education,
School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
2. Department of Mechanical Engineering, Faculty of Science and Engineering, Ritsumeikan University,
1-1-1Nojihigashi, Kusatsu, Shiga 525-8577, Japan)
School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
2. Department of Mechanical Engineering, Faculty of Science and Engineering, Ritsumeikan University,
1-1-1Nojihigashi, Kusatsu, Shiga 525-8577, Japan)
Abstract: Al86Ni7Y4.5Co1La1.5 (mole fraction, %) alloy powder was produced by argon gas atomization process. After high-energy ball milling, the powder was consolidated by vacuum hot press sintering and spark plasma sintering (SPS) under different process conditions. The microstructure and morphology of the powder and consolidated bulk sample were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is shown that amorphous phase appears when ball milling time is more than 100 h, and the bulk sample consolidated by SPS can maintain amorphous/ nanocrystalline microstructure but has lower relative density. A compressive strength of 650 MPa of Al86Ni7Y4.5Co1La1.5 nanostructured samples is achieved by vacuum hot extrusion (VHE).
Key words: mechanical alloying; aluminum alloy; nanocrystalline alloy; amorphous; spark plasma sintering; hot extrusion