| Ni-base composites are important alloys used in gas turbines.Most of the nickel-base composites have good heat resistance, corrosion resistance, high temperatures, large surface curvature,thermostablieity,excellent mechanical properties and so on.The nickel-base composites were made by powder-metallurgy using Ni alloys as matrix. We studied the effects of precipitates through aging treatment on the strengthened nickel-base composites. The amount of Ni deposited on the CNTs can be controlled by selecting the appropriate electroless plating conditions.The purification of CNTs,uniformly dispersion of CNTs among alloy powders,the thermal stability of CNTs and Ni and the densification of the composites were analyzed.By using XRD, SEM, VSM, tensile test and hardness test techniques,the microstructure,the mechanical properties and the processing parameters of the composites were examined and optimized.In addition,the effects of the microstructure on the overall mechanical properties were related.The CNTs content affected significantly the mechanical properties of the composites.The hardness,tensile strength,modulus and yield strength of the composites firstly increase and then reduce with CNTs content increasing.when CNTs content is 15vol.%.They are increased 35% in relation to the matrix during the same CNTs. |
