In order to estimate applicability to mechanical alloying of Ni-based alloy powder as the master alloy for preparing O.D.S. superalloy, milling characteristics of Ni-Co-Cr-Mo (AsI), Ni-Co-Mo (AsII) and Ni-W-Mo (MaI) atomized powders were examined by using vibration ball mill. Results were summarized as follows:
1) The rolling force of sintered preforms became a good index to assess the granulation characteristic of powder in the mechanical alloying. The rolling force of AsI, AsII and MaI preformes were of 1010, 730 and 750 MPa respectively. The values for AsI and MaI were close to that of carbonyl-Ni preform, i.e., 690 MPa.
2) Mean particle sizes of milled powder were influenced by the annealing temperature, carbon contents, atmospheres during milling and also surface conditions of milling balls and pots.
3) By milling in the vibration ball mill, AsI particles, pool in ductility, were granulated to coarse spherical particles, while AsII and MaI formed very coarse flaky ones having a lamellae structure similar to carbonyl-Ni granules.