The coarsening and ageing hardening behaviors of γ' particles in superalloy GH742 have been investigated by field emission scanning electron microscopy(FESEM),coarsening kinetics calculation and microhardness testing when ageing at 1 050,950 and 900 ℃ for different time.The cube of γ' particle size and ageing time follows a linear law as predicted by LSW theory.The particle size distributions give better fit to the LSW theoretical distribution.The activation energy for γ' coarsening is accurately determined to have 245.06±14.42 kJ/mol when considering the effect of temperature on the solution concentrations in matrix.Based on the activation energy,the coarsening kinetics of γ' particle is predicted as r3t=7.35×1015Ce/Texp-(245 060±14 420)/RTt.The microhardness studies indicate that microhardness decreases rapidly with increasing the ageing temperature and it has a maximum value corresponding to a critical particle size beyond which the microhardness increase stalls with increasing the ageing time.
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机译:铝合金/碳纤维/聚醚醚酮混和十字迭奈米复材积层板之研制与高温下机械行为 Fabrication and Mechanical Behavior of Al/APC-2 Hybrid Cross-Ply Nanocomposite Laminates at Elevated Temperature
机译:Effects of calcination temperature and water-washing treatment on n-hexane hydroisomerization behavior of pt-promoted sulfated zirconia based catalysts