Process for producing sm.sub.2 co.sub.17 alloy suitable for use as

Abstract

A process for producing an Sm.sub.2 Co.sub.17 alloy suitable for use as a permanent magnet, the alloy also containing iron, copper and zirconium or a similar group IVB or VB transition metal, and optionally praseodymium in partial replacement of the samarium. The process comprises providing the alloy in a preliminary form, sintering the alloy at an elevated temperature to achieve a high density and high remanence, selecting a solution heat treatment temperature which is marginally below the solid+liquid/solid phase transformation temperature of said alloy, cooling the sintered alloy body from the sintering temperature to the solution treatment temperature in a controlled manner to put the alloy constituents into a substantially uniform 2-17 Sm-Co solid solution, holding at the solid solution treatment temperature, quenching the alloy to room temperature, reheating the alloy to a first aging temperature to transform the 2-17 Sm-Co solid solution into a structure comprising a network of the 1-5 Sm-Co phase within a 2-17 Sm-Co matrix, cooling the alloy to a second aging temperature in a controlled manner to cause regions of 2-17 Sm-Co phase to nucleate coherently within the 1-5 Sm-Co phase network and create lattice strain which results in high coercivity and good loop squareness, and cooling the alloy to room temperature.