Abstract
The purpose of this paper is to discuss the hardening mechanisms of Ag-Ni sintered two phase alloys containing fibrous Ni prepared by cold drawing. Deformation behavior during cold drawing and softening behavior during isochronal annealing were studied by hardness measurements.
The results are summerized as follows:
(1) Ag-Ni alloys containing fibrous Ni were obtained by cold drawing of sintered alloys. The hardness of these alloys was higher than that calculated by the mixing rule based on the hardness of Ag and Ni.
(2) In the region of low Ni volume fractions and low reduction, the matrix and secondary phases were deformed with different strain. Deformation in the matrix was larger than that in the secondary phase.
(3) Hardening by fine structure and strain hardening were distingusihed. Structural hardening was represented by the Hall-Petch type relation.
(4) Ag-Ni alloys containing fibrous Ni had a higher recrystallization temperature than that of Ni. The main cause of this behavior was the inhibition of the strain energy relief due to the fine structure.
