High-energy product rare earth-iron magnet alloys

A method of making a composition having permanent magnet properties at room temperature comprising

• preparing a melt of a composition comprising, on an atomic percentage basis of the total composition, at least about 0.5 percent boron, about 10 to 50 percent of one or more rare earth elements taken from the group consisting of neodymium and praseodymium, and one or more transition metal elements taken from the group consisting of iron and mixtures of iron and cobalt where iron constitutes at least about 50 percent of the total composition, such molten composition being susceptible to being rapidly cooled to solidification over a determinable and controllable range of cooling rates within which range a series of fine grained crystalline products are formed that respectively display (a) values of magnetic coercivity that continually increase toward a maximum value and decrease from such value as the cooling rate is increased, and (b) values of magnetic remanence that increase over at least a part of such range as the cooling rate is increased, and
• continually rapidly cooling portions of the melt by ejecting them onto a moving quench surface to form a fine grained crystalline product while controlling the cooling rate within said cooling range by a method comprising controlling the velocity of the quench surface such that the product has a desired combination of magnetic coercivity and remanence.