Production Technology Of Ni-Based Superalloy Hollow Sphere Foams

Porous nickel-based superalloys were fabricated by powders sintering in the article. Polystyrene was used to be space-holder, K405 alloy was used to be material and polyvinyi was used to be binder in the experiment. The effection of polyvinyi consistency and addition to paintability was discussed. The sintering craft of hollow sphere foams was determined. By means of scanning electron microscopy(SEM), X-ray diffraction(XRD), the microstructure, phase composition and mechanical property of alloys were investigated.Hollow sphere foams were produced under: heating-up to 350℃with a speed of 5.4℃/min, then heat preservation for 20min, later heating-up to 1150℃fleetly. Relative density of hollow sphere foams whose particle size were less than 38μm and 38～53μm, were 0.113 and 0.074 under the optimum craft. Wall thickness of hollow sphere foams was homogeneous. Contraction percentage of hollow sphere foams minished along with the increment of particle size.Sintereing necks grow up along with the increasement of hours, and the microstructure was to be compact. Porosity increased along with the increment of particle size under the same sintering condition.γ-phase was matrix in K405 alloys hollow sphere foams, there were also someγ′-phase separate out at the same time. Compared to simple cubic lattice, body-centered cubic hollow sphere foams have higher relative density, stress and modulus. Under the same relative density, body-centered cubic hollow sphere foams were 11.2% and 2.2% larger than simple cubic lattice in stress and modulus. When hollow sphere foams were compressed, most of fractures concentrate on the sintereing necks. Sintereing necks grown up along with the minish of particle sizes.