Fabrication of Sintered Compact from Aluminum Powder Coated with Tin Deposits by Magnetron DC Sputtering
Fabrication of sintered compact from aluminum powder coated with tin deposits was examined, in order to enhance the bonding among the aluminum particles under the assistance of tin and thereby the sintering effect of the aluminum powder, aiming at improving the mechanical properties of sintered aluminum materials. For the coating of aluminum powder with tin deposits, the deposition of pure tin onto the aluminum particles was carried out by magnetron DC sputtering during the self-convective motion of the aluminum powder in a vacuum chamber. The tablet consisting of the aluminum powder coated with tin deposits was sintered at 650°C in a vacuum chamber for 2 hours, while the tablet consisting of non-coated aluminum powder was also sintered under the same condition for comparison. The sintered compact from the coated aluminum powder was solid and uniform, and its consolidation reached over 95% while that from non-coated aluminum powder was around 85%. According to tensile tests, the tensile strength of the sintered compact from the coated aluminum powder was 75.4N/mm2 while that from non-coated aluminum powder was 71.0N/mm2, and the elongation of the sintered compact from the coated aluminum powder reached over 20% while that from non-coated aluminum powder was around 10%. Therefore it was found that the consolidation and the mechanical properties of the sintered compact consisting of aluminum powder were considerably improved by this powder coating process.