The changes in structure and the hardness of two electroless deposited Ni-P alloy coatings (with P content of 1.5 and 9.5 wt pet) with heat treatment have been studied by XRD and TEM. The deposits containing 1.5 wt pe...The changes in structure and the hardness of two electroless deposited Ni-P alloy coatings (with P content of 1.5 and 9.5 wt pet) with heat treatment have been studied by XRD and TEM. The deposits containing 1.5 wt pet P can be represented as an fee NiP supersaturated solid solution of 5 similar to 10 nm microcrystallites, whereas the deposits containing 9.5 wt pet P are amorphous. The heat treatment process induces crystallization of amorphous Ni to Ni phosphides and fee Ni. Both of the deposits reach maximum hardness after annealing at 400 degrees C for 1 h. All coated steel specimens are inferior in fatigue strength to uncoated steel specimens mainly due to the poor fatigue resistance of the coating itself.展开更多
Initial process is influenced by substrate microstructure according to the study of initial stage of electroless plating on low carbon steel and pure iron. For low carbon steels, depositing on cementite is prior to th...Initial process is influenced by substrate microstructure according to the study of initial stage of electroless plating on low carbon steel and pure iron. For low carbon steels, depositing on cementite is prior to that on ferrite; and for pure iron, the grain boundaries and some favourable grains are deposited more easily. The initial reactions of electroless depositing of Ni-P alloy have been tentatively proposed.展开更多
The effects of solution (quench) temperature on the properties of SiCW/Al composite have been investigated using tensile tests. The experiments indicate that the solution temperature of the composite fabricated by P/M...The effects of solution (quench) temperature on the properties of SiCW/Al composite have been investigated using tensile tests. The experiments indicate that the solution temperature of the composite fabricated by P/M technique can be raised to 560 degrees C. The tensile strength of the composite is obviously dependent on solution (quench) temperature and the composite solutionized at 540 degrees C exhibits a maximum of tensile strength and elongation-to-failure. These results can be accounted for by the variation of the dislocation density in the composite.展开更多
As an effective and economical surface strengthening method, flame spray technology is now widely used in surface shielding of engineering materials and equipments or parts repairments. However, the porosities inside ...As an effective and economical surface strengthening method, flame spray technology is now widely used in surface shielding of engineering materials and equipments or parts repairments. However, the porosities inside the coating and the poor bonding of the coating strength展开更多
文摘The changes in structure and the hardness of two electroless deposited Ni-P alloy coatings (with P content of 1.5 and 9.5 wt pet) with heat treatment have been studied by XRD and TEM. The deposits containing 1.5 wt pet P can be represented as an fee NiP supersaturated solid solution of 5 similar to 10 nm microcrystallites, whereas the deposits containing 9.5 wt pet P are amorphous. The heat treatment process induces crystallization of amorphous Ni to Ni phosphides and fee Ni. Both of the deposits reach maximum hardness after annealing at 400 degrees C for 1 h. All coated steel specimens are inferior in fatigue strength to uncoated steel specimens mainly due to the poor fatigue resistance of the coating itself.
文摘Initial process is influenced by substrate microstructure according to the study of initial stage of electroless plating on low carbon steel and pure iron. For low carbon steels, depositing on cementite is prior to that on ferrite; and for pure iron, the grain boundaries and some favourable grains are deposited more easily. The initial reactions of electroless depositing of Ni-P alloy have been tentatively proposed.
文摘The effects of solution (quench) temperature on the properties of SiCW/Al composite have been investigated using tensile tests. The experiments indicate that the solution temperature of the composite fabricated by P/M technique can be raised to 560 degrees C. The tensile strength of the composite is obviously dependent on solution (quench) temperature and the composite solutionized at 540 degrees C exhibits a maximum of tensile strength and elongation-to-failure. These results can be accounted for by the variation of the dislocation density in the composite.
文摘As an effective and economical surface strengthening method, flame spray technology is now widely used in surface shielding of engineering materials and equipments or parts repairments. However, the porosities inside the coating and the poor bonding of the coating strength
