PROCESS FOR PRODUCING SM.SUB.2CO IN17 XX ALLOY SUITABLE FOR USE AS PERMANENT MAGNETS

摘要

ABSTRACT OF THE DISCLOSUREA process for producing an Sm2Co17 alloysuitable for use as a permanent magnet, the alloy alsocontaining iron, copper and zirconium or a similargroup IVB or VB transition metal, and optionally praseo-dymium in partial replacement of the samarium. Theprocess comprises providing the alloy in a preliminaryform, sintering the alloy at an elevated temperatureto achieve a high density and high remanence, selectinga solution heat treatment temperature which is. marginally be-low the solid+liquid/solid phase transformation tempera-ture of said alloy, cooling the sintered alloy body fromthe sintering temperature to the solution treatment tem-perature in a controlled manner to put the alloy consti-tuents into a substantially uniform 2-17 Sm-Co solidsolution, holding at the solid solution treatment tem-perature, quenching the alloy to room temperature, re-heating the alloy to a first aging temperature to trans-form the 2-17 Sm-Co solid solution into a structure com-prising a network of the 1-5 Sm-Co phase within a 2-17Sm-Co matrix, cooling the alloy to a second aging tem-perature in a controlled manner to cause regions of2-17 Sm-Co phase to nucleate coherently within the1-5 Sm-Co phase network and create lattice strain whichresults in high coercivity and good loop squareness,and cooling the alloy to room temperature.