The Consolidation Behavior of L1 2 Phase Al 3 Zr & (Al+12.5at%) 3 Zr Powders with Nanocrystalline Structure During Spark Plasma Sintering

The spark plasma sintering (SPS) of L12 phase Al3Zr and (Al+12.5at.%Cu)3Zr powders with a nanocrystalline microstructure has been studied to produce bulk intermetallic compounds which maintain metastable structures such as L12 structure and nanocrystalline microstructure. The powders were prepared by 10 h planetary ball milling (PBM). Full-density L12 (Al+12.5at.%Cu)3 Zr intermetallic compounds were obtained by SPS for 0 min. at 600°C. The smallest grain size was obtained in the specimen prepared at 600°C for 0 min., which was 20-30 nm as confirmed by TEM observation. Accordingly, the highest micro-hardness, 989.5HV, was obtained in the specimen and this value was three times higher than those of the specimens with micro grain sizes. Full density Al3Zr intermetallics were prepared by SPS at 700°C for 0 min.. However, their crystal structure was D023 and micro-hardness was 778.1HV. By using SPS, the sintering time can be reduced within 10 min.