Improvement of powder properties and chemical homogeneity of partially alloyed iron powder by a nanopowder process

Abstract

The present investigation focuses on the improvements in chemical homogeneity and related powder properties of partially alloyed Fe1.50Cu1.75Ni0.50Mo powder by using a nanopowder process. The nanosized oxide powders of CuONiOMoO3 were prepared by ballmilling for the alloying elements and blended with iron powders. The powder mixture was annealed in a reducing atmosphere, in order to reduce the oxide powders and thereafter partially alloyed with the iron powder. The produced powder was used to evaluate the microstructure, chemical composition, compressibility, and sinterability. It was found that the powder had a uniform distribution of alloying elements with high compositional homogeneity. The fine alloying elements were mostly located in the grooves of the iron powder surface, yielding morphological change, which effectively improved the flow, packing and compaction properties of the powder. The nanopowder process also promoted a diffusion reaction during sintering at 1200°C for 2 h with a homogeneous microstructure and chemical composition.